The present disclosure generally relates to cancer diagnosis, and particularly, to a system and method for real-time diagnosis of cancer cells in a sample via monitoring photocurrent changes of a graphene/silicon schottky junction in the presence of the sample attached to graphene/silicon schottky junction and under light illumination.
Cancer has become one of the greatest challenges of global healthcare. According to the World Health Organization (WHO), cancer is now the second leading cause of death in the world. Glioma, a general term describing primary brain tumors, is the most frequently occurring tumor of central nervous system. Based on the level of malignancy, the World Health Organization (WHO) classifies gliomas as grade I to grade IV. Glioblastoma multiform (GBM) is designated as grade IV and is the most malignant and common primary brain cancer in adults (more than 60%). GBM is known as malignant and invasive cancer with high resistance to various treatments. Most of patients only have 14-15 months of survival after diagnosis and less than 5% will survive for 5 years. In more advanced stages of a diffusely invasive brain cancer, surgery cannot fully remove the invasive cells and this creates recurrence and increased mortality rates. Such an occurrence may be prevented if diagnosis is made possible in the earlier stages of tumor development, where the tumor cannot be visually distinguished. As seen from an increasing number of new cancer cases, and increasing death rates for different cancers of the nervous system, early diagnosis will play a vital role to control, help select the best treatment option, and eventually, decrease the mortality rate of such cancers in the future.
In recent years, nanotechnology has created rapid advances in development of various biosensors based on available solid state devices and nanostructures. Among these, carbon nanostructures (carbon nanotubes, graphene, graphene oxide, etc.) have been widely used as sensing platforms for different biological material. Biocompatibility and excellent electrical properties of these nanostructures, along with their low cost and high sensitivity, has prompted their application as both transducers, where they directly interact with target biomaterial, or templates, where they capture and immobilize biological transducers, such as proteins, DNA, RNA, etc. in various biosensors in different studies. However, most of the proposed sensors for cancer cells detection are suitable for biomarker detection. Whereas, there is a need to analyze cancer cells themselves. Furthermore, reliability and validity of results obtained by biomarker detection are the main problem that limits use of biomarkers as a diagnostic or analyzing variable in a clinical trial or in an epidemiologic study.
Hence, there is a need for a label-free and real-time sensor, method, and system to detect cancer cells. There is also a need for a highly precise and fast approach for detecting cancer cells in a sample acquired from a person suspected to have cancer utilizing a simply fabricated and non-expensive sensor.
This summary is intended to provide an overview of the subject matter of this patent, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed embodiments. The proper scope of this patent may be ascertained from the claims set forth below in view of the detailed description below and the drawings.
In one general aspect, the present disclosure is directed to a system for detecting Glioblastoma cancer cells. The system may include a biosensor, a light source placed above the biosensor, an electrical stimulator-analyzer device electrically connected to the biosensor, and a processing unit electrically connected to the electrical stimulator-analyzer device and the light source.
In an exemplary embodiment, the biosensor may include a semiconductor layer, an electrically passivating layer, two electrodes, and a graphene layer. In an exemplary embodiment, the semiconductor layer may include a silicon (Si) wafer and electrically passivating layer may include a silicon dioxide (SiO2) layer coated on a first portion of the Si wafer. In an exemplary embodiment, the two electrodes may include a first electrode deposited on a second portion of the Si wafer and a second electrode deposited on the SiO2 layer. In an exemplary embodiment, the graphene layer may be coated on parts of the substrate and the second electrode forming a graphene-Si Schottky junction between the Si wafer and the graphene layer. In an exemplary embodiment, a first side of the graphene layer may be in contact with the Si wafer and a second side of the graphene layer may be in contact with the second electrode. In an exemplary embodiment, the graphene-Si Schottky junction may be configured to put a sample thereon. In an exemplary embodiment, the sample may be in contact with the graphene side of the graphene-Si Schottky junction.
In an exemplary embodiment, the light source may include a light emitting device with a wavelength range of 300 nm to 1000 nm. In an exemplary embodiment, the light source may be configured to irradiate a light beam to the graphene-Si Schottky junction with the sample thereon. In an exemplary embodiment, the electrical stimulator-analyzer device may be electrically connected to the two electrodes of the biosensor. In an exemplary embodiment, the stimulator-analyzer device may include an electrical voltage generator and an electrical current sensor. In an exemplary embodiment, the electrical voltage generator may be configured to apply a voltage between the two electrodes and the electrical current sensor may be configured to measure a produced electrical current between the two electrodes responsive to the applied voltage.
In an exemplary embodiment, the processing unit may include a memory having processor-readable instructions stored therein and a processor. In an exemplary embodiment, the processor may be configured to access the memory and execute the processor-readable instructions to configure the processor to perform a method. In an exemplary embodiment, the method may include irradiating a light beam in a range of 500 nm to 900 nm to the graphene-Si Schottky junction with the sample thereon utilizing the light source, applying a first voltage of −1 V and a second voltage of −0.05 V between the two electrodes utilizing the electrical stimulator-analyzer device, measuring a first electrical current generated between the two electrodes responsive to the applied first voltage and a second electrical current generated between the two electrodes responsive to the applied second voltage utilizing the electrical stimulator-analyzer device, and detecting a presence of Glioblastoma cancer cells in the sample if a difference between the first electrical current and the second electrical current is detected to be more than 10 nA.
In an exemplary embodiment, irradiating the light beam to the graphene-Si Schottky junction with the sample thereon may include irradiating the light beam with a wavelength of 850 nm to the graphene-Si Schottky junction with the sample thereon.
In an exemplary embodiment, detecting the presence of Glioblastoma cancer cells in the sample may further include differentiating between T98G Glioblastoma cells and U87 Glioblastoma cells in the sample. In an exemplary embodiment, differentiating between T98G Glioblastoma cells and U87 Glioblastoma cells in the sample may include detecting a presence of T98G Glioblastoma cells in the sample if the first electrical current is less than 1 μA. In another exemplary embodiment, differentiating between T98G Glioblastoma cells and U87 Glioblastoma cells in the sample may include detecting a presence of T98G Glioblastoma cells in the sample if the first electrical current is more than 1 μA.
In an exemplary embodiment, the sample may include a biological sample containing biological cells acquired from a person suspected to have Glioblastoma cancer. In an exemplary embodiment, the sample may include a biopsied sample from a cancer-suspicious mass in body of the person, and combinations thereof.
In an exemplary embodiment, each of the two electrodes may include a gold (Au) film with a thickness in a range of 50 nm to 200 nm. In an exemplary embodiment, the graphene layer may include a monolayer graphene. In an exemplary embodiment, the system may further include a sample holder. In an exemplary embodiment, the sample holder may be placed around the graphene-Si Schottky junction. In an exemplary embodiment, the sample holder may include one or more sidewalls enclosing an area of the graphene-Si Schottky junction with the sample placed thereon. In an exemplary embodiment, the sample holder may be configured to keep the sample on surface of the graphene-Si Schottky junction, prevent the sample from flowing out of the graphene-Si Schottky junction, and prevent entrance of pollutants or external materials to the graphene-Si Schottky junction.
In one more general aspect, the present disclosure is directed to a system for detecting cancer cells. The system may include a biosensor, a light source placed above the biosensor, an electrical stimulator-analyzer device electrically connected to the biosensor, and a processing unit electrically connected to the electrical stimulator-analyzer device and the light source.
In an exemplary embodiment, the biosensor may include a semiconductor layer, an electrically passivating layer, two electrodes, and a graphene layer. In an exemplary embodiment, the electrically passivating layer may be coated on a first portion of the semiconductor layer. In an exemplary embodiment, the two electrodes may include a first electrode deposited on a second portion of the semiconductor layer and a second electrode deposited on the electrically passivating layer. In an exemplary embodiment, the graphene layer may be coated on parts of the semiconductor layer, the electrically passivating layer, and the second electrode forming a graphene-semiconductor Schottky junction between the semiconductor layer and the graphene layer. In an exemplary embodiment, a first side of the graphene layer may be in contact with the semiconductor layer and a second side of the graphene layer may be in contact with the second electrode. In an exemplary embodiment, the graphene-semiconductor Schottky junction may be configured to put a sample thereon.
In an exemplary embodiment, the light source may include a light emitting device with a wavelength range of 300 nm to 1000 nm. In an exemplary embodiment, the light source may be configured to irradiate a light beam to the graphene-semiconductor Schottky junction with the sample thereon. In an exemplary embodiment, the electrical stimulator-analyzer device may be electrically connected to the two electrodes of the biosensor. In an exemplary embodiment, the stimulator-analyzer device may include an electrical voltage generator and an electrical current sensor. In an exemplary embodiment, the electrical voltage generator may be configured to apply a sweeping range of reverse bias voltages between the two electrodes and the electrical current sensor may be configured to measure a set of produced electrical currents between the two electrodes responsive to the applied sweeping range of reverse bias voltages.
In an exemplary embodiment, the processing unit may include a memory having processor-readable instructions stored therein and a processor. In an exemplary embodiment, the processor may be configured to access the memory and execute the processor-readable instructions to configure the processor to perform a method. In an exemplary embodiment, the method may include generating a set of photocurrents in a reverse bias regime through the graphene-Si Schottky junction with the sample placed thereon, measuring the set of generated photocurrents in the reverse bias regime through the graphene-Si Schottky junction with the sample placed thereon, and detecting a presence of cancer cells in the sample if a change in photocurrent within the reverse bias regime is detected.
In an exemplary embodiment, generating the set of photocurrents in the reverse bias regime through the graphene-Si Schottky junction with the sample placed thereon may include irradiating a light beam in a range of 500 nm to 900 nm to the graphene-Si Schottky junction with the sample thereon utilizing the light source and applying a sweeping range of reverse bias voltages between the two electrodes utilizing the electrical stimulator-analyzer device. In an exemplary embodiment, applying the sweeping range of reverse bias voltages between the two electrodes may include applying a set of voltage in a range of −1 V to −0.01 V between the two electrodes.
In an exemplary embodiment, detecting the presence of cancer cells in the sample may include detecting at least two photocurrent values of the measured set of the generated photocurrents being different with each other by a difference magnitude of more than 10 nA.
In an exemplary embodiment, the semiconductor layer may include a silicon (Si) wafer and the electrically passivating layer may include a silicon dioxide (SiO2) layer coated on a first portion of the Si wafer.
In an exemplary embodiment, the sample may include a biological sample containing biological cells acquired from a person suspected to have cancer. In an exemplary embodiment, the sample may include a biopsied sample from a cancer-suspicious mass in body of the person, and combinations thereof.
In an exemplary embodiment, each of the two electrodes may include a gold (Au) film with a thickness in a range of 50 nm to 200 nm. In an exemplary embodiment, the graphene layer may include a monolayer graphene film. In an exemplary embodiment, the system may further include a sample holder. In an exemplary embodiment, the sample holder may be placed around the graphene-semiconductor Schottky junction. In an exemplary embodiment, the sample holder may include one or more sidewalls enclosing an area of the graphene-semiconductor Schottky junction with the sample placed thereon. In an exemplary embodiment, the sample holder may be configured to keep the sample on surface of the graphene-semiconductor Schottky junction, prevent the sample from flowing out of the graphene-semiconductor Schottky junction, and prevent entrance of pollutants or external materials to the graphene-Si Schottky junction.
The drawing figures depict one or more embodiments in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.
In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
Herein, an exemplary biosensor for cancer cells detection in a biological sample is described. An exemplary biosensor may comprise a mono-layer graphene/(n-type)Si Schottky junction. Furthermore, an exemplary system and method utilizing an exemplary biosensor are described for detection of cancer cells in an exemplary biological sample. An exemplary method may include putting an exemplary biological sample on an exemplary graphene/Si Schottky junction of an exemplary biosensor, irradiating a light beam onto an exemplary graphene/Si Schottky junction with an exemplary biological sample thereon, and monitoring photocurrent of exemplary graphene/Si Schottky junction while applying a reverse bias voltage regime (diode voltage (VD) of less than zero) in the presence of an exemplary biological sample. In an exemplary embodiment, photocurrent of exemplary graphene/Si Schottky junction may be monitored by recording a set of reverse electrical currents respective to an exemplary applied range of reverse voltages. In an exemplary embodiment, each type of cancer cells may show a unique behavior of changes in reverse electrical currents versus an exemplary applied range of reverse voltages. In an exemplary embodiment, an exemplary method may further include comparing an exemplary set of reverse electrical currents versus an exemplary applied range of reverse voltages (an exemplary I-V set) associated with an exemplary biological sample with a plurality of reference I-V sets associated with a respective plurality of cancer cells and detecting a presence of a first-type cancer cells in an exemplary biological sample if an exemplary I-V set is identical to a first reference I-V set associated with the first-type cancer cells. In an exemplary embodiment, the plurality of reference I-V sets associated with the respective plurality of cancer cells may be generated as a calibration dataset for a plurality of cancer cell types utilizing a plurality of biological samples with known cancer type. An exemplary biosensor, system, and method may not only be capable of distinguishing two different cancer cell types, but may also be utilized easily to differentiate cancer cells from healthy human cells.
As used herein, “a reverse electrical current” and “a reverse voltage” may respectively refer to electrical current and electrical voltage in a reverse bias regime of an exemplary graphene/Si Schottky junction. An exemplary graphene/Si Schottky junction comprises an exemplary diode structure having a reverse bias regime and a forward bias regime in a current-voltage (I-V) diagram including a plurality of electrical currents generated within an exemplary graphene/Si Schottky junction versus a respective plurality of applied electrical voltages to an exemplary graphene/Si Schottky junction. In forward bias, a positive terminal of an electrical voltage generator device is connected to p-type or metallic material of an exemplary diode (herein, graphene side) and a negative terminal is connected to n-type material (herein, Si side) so that electrons are injected into n-type material and holes are transferred from Si to the graphene. Whereas, in reverse bias, a reverse process is applied and electrons must overcome the Schottky barrier to reach the conduction band of the n-type semiconductor.
In an exemplary embodiment, an exemplary sample may include a biological sample containing cells. In an exemplary embodiment, an exemplary biological sample may be acquired from a person or an animal suspected to have cancer. In an exemplary embodiment, an exemplary biological sample may include at least one of a blood sample, a biopsied sample from a mass suspicious to be cancerous in a person's body, a cell line, a cell-containing liquid sample drawn from a living body, and combinations thereof. In an exemplary embodiment, an exemplary biological sample may include a sample acquired from a person suspected to have Glioblastoma cancer. As used herein, “Glioblastoma” is an aggressive type of cancer that may occur in brain and/or spinal cord. In an exemplary embodiment, exemplary system 100 may be utilized for detecting Glioblastoma cancer cells in an exemplary sample.
In an exemplary embodiment, biosensor 102 may include a substrate 103, two electrodes 122 and 124, and a graphene layer 126 coated on parts of surface of substrate 103 and two electrodes 122 and 124. In an exemplary embodiment, substrate 103 may include a semiconductor layer 118 and an electrically passivating layer 120 coated on a first portion 117 of semiconductor layer 118. In an exemplary embodiment, first portion 117 of semiconductor layer 118 may include a first half of semiconductor layer 118. In an exemplary embodiment, semiconductor layer 118 may include a silicon (Si) wafer and electrically passivating layer 120 may include a silicon dioxide (SiO2) layer coated on surface of a first half of an exemplary Si wafer. In an exemplary embodiment, semiconductor layer 118 may include an n-type Si wafer. In an exemplary embodiment, semiconductor layer 118 may have a thickness of about 500 μm. In an exemplary embodiment, electrically passivating layer 120 may have a thickness in a range of about 200 nm to about 1 μm.
In an exemplary embodiment, two electrodes 122 and 124 may include a first electrode 122 deposited on electrically passivating layer 120 and a second electrode 124 deposited on a second portion 119 of semiconductor layer 118. In an exemplary embodiment, each of two electrodes 122 and 124 may include a gold (Au) film with a thickness in a range of about 50 nm to about 200 nm.
In an exemplary embodiment, graphene layer 126 may include a monolayer graphene film coated on parts of surface of electrode 124 and substrate 103. In an exemplary embodiment, graphene layer 126 may cover parts of electrode 124, electrically passivating layer 120, and semiconductor layer 118. In an exemplary embodiment, coated graphene layer 126 may form an exemplary graphene-semiconductor Schottky junction 128 between semiconductor layer 118 and graphene layer 126. In an exemplary embodiment, exemplary graphene-semiconductor Schottky junction 128 may comprise a graphene-Si Schottky junction. In an exemplary embodiment, exemplary graphene-semiconductor Schottky junction 128 may be configured to be able to receive or have put on it an exemplary sample 129. In an exemplary embodiment, a first side of graphene layer 126 may be in contact with semiconductor layer 118 and a second side of graphene layer 126 may be in contact with second electrode 124.
In an exemplary embodiment, biosensor 102 may further include a sample holder.
In another general aspect of the present disclosure, a method for fabricating an exemplary biosensor 102 is described.
Furthermore,
In an exemplary embodiment, step 204 may include removing a first half 311 of SiO2 layer 314 from surface of a respective first half 310 of Si wafer 312 considering a hypothetical symmetric line 302 at the middle of SiO2 layer 314 and a respective hypothetical symmetric line 304 at the middle of Si wafer 312. In an exemplary embodiment, exemplary first half 311 of exemplary SiO2 layer 314 may be removed using a standard photolithography technique through a two-step process shown in
Furthermore, step 206 may include forming two exemplary electrodes similar to electrodes 122 and 124. In an exemplary embodiment, step 206 may include forming an exemplary first electrode on first half 310 of Si wafer 312 with bare surface 318 and forming an exemplary second electrode on remaining second half 320 of SiO2 layer 314. In an exemplary embodiment, step 206 may be done through four steps schematically illustrated in
Moving to step 208, a graphene-Si Schottky junction similar to graphene-semiconductor Schottky junction 128 may be formed by coating a graphene layer on parts of surface of Si wafer 312, remaining second half 320 of SiO2 layer 314, and second electrode 330. In an exemplary embodiment, step 208 may include coating an exemplary graphene layer 332 on parts of surface of Si wafer 312, remaining second half 320 of SiO2 layer 314, and second electrode 330 as illustrated in
In an exemplary embodiment, exemplary method 200 may further include placing an exemplary sample holder 334, similar to exemplary sample holder 130, around a portion or the entire surface of graphene-Si Schottky junction 333 as illustrated in
Referring back to
Referring to
In an exemplary embodiment, processing unit 108 may include a memory having processor-readable instructions stored therein and a processor. In an exemplary embodiment, the processor may be configured to access the memory and execute the processor-readable instructions. In an exemplary embodiment, executing the processor-readable instructions by the processor may configures the processor to perform a method. In an exemplary embodiment, the method may include an exemplary method for detecting cancer cells in a sample described herein below.
In another general aspect of the present disclosure, an exemplary method for detecting cancer cells in an exemplary sample is described. In an exemplary embodiment, an exemplary method may be carried out utilizing exemplary system 100 described hereinabove.
In detail, step 401 may include putting an exemplary sample, for example, sample 129 in contact with graphene side 142 of graphene-semiconductor Schottky junction 128 of biosensor 102. In an exemplary embodiment, exemplary sample 129 may include a sample including biological cells acquired from a person suspected to have cancer. In an exemplary embodiment, exemplary sample 129 may include at least one of a blood sample drawn from a person, a biopsied sample acquired from a person, a sample containing biological cells suspected to be cancerous, and combinations thereof. In an exemplary embodiment, exemplary sample 129 may include a biopsied sample from a mass suspected to be a cancerous tumor in a person's body. In an exemplary embodiment, putting exemplary sample 129 in contact with graphene side 142 of graphene-semiconductor Schottky junction 128 may include dropping or placing exemplary sample 129 inside sample holder 130 on graphene-semiconductor Schottky junction 128. In an exemplary embodiment, putting exemplary sample 129 in contact with graphene side 142 of graphene-semiconductor Schottky junction 128 may lead to attaching/adhering exemplary sample 129 to graphene side 142 of graphene-semiconductor Schottky junction 128 due to dangling bonds of graphene.
Furthermore, step 402 may include generating an exemplary set of photocurrents in a reverse bias regime passed through graphene-semiconductor Schottky junction 128. In an exemplary embodiment, generating an exemplary set of photocurrents through graphene-semiconductor Schottky junction 128 may be carried out utilizing electrical stimulator-analyzer device 106 and light source 104.
In an exemplary embodiment, step 406 of irradiating an exemplary light beam to exemplary sample 129 on graphene-semiconductor Schottky junction 128 may include irradiating an exemplary light beam to biosensor 102. In an exemplary embodiment, irradiating an exemplary light beam to exemplary sample 129 on graphene-semiconductor Schottky junction 128 may include irradiating an exemplary light beam to graphene-semiconductor Schottky junction 128 while exemplary sample 129 being on graphene-semiconductor Schottky junction 128 using exemplary light source 104. In an exemplary embodiment, irradiating an exemplary light beam to graphene-semiconductor Schottky junction 128 with exemplary sample 129 thereon may include irradiating an exemplary light beam with a wavelength in a range of about 500 nm to about 900 nm to graphene-semiconductor Schottky junction 128 with exemplary sample 129 thereon utilizing light source 104.
In an exemplary embodiment, step 407 of applying an exemplary set of voltages in reverse bias regime to graphene-semiconductor Schottky junction 128 may include applying an electrical voltage to graphene-semiconductor Schottky junction 128 in such a way that semiconductor side (Si side) 140 may be held at a higher voltage than graphene side 142. In an exemplary embodiment, step 407 of applying an exemplary set of voltages in reverse bias regime to graphene-semiconductor Schottky junction 128 may include applying a set of voltages in a range of about −1 V to about −0.01 V to graphene-semiconductor Schottky junction 128. In an exemplary embodiment, applying an exemplary set of voltages in reverse bias regime to graphene-semiconductor Schottky junction 128 may include applying an exemplary set of voltages in an exemplary reverse bias regime to graphene-semiconductor Schottky junction 128 in the presence of exemplary sample 129 on graphene-semiconductor Schottky junction 128 while irradiating the light beam to graphene-semiconductor Schottky junction 128. In an exemplary embodiment, applying an exemplary set of voltages in reverse bias regime to graphene-semiconductor Schottky junction 128 may include applying a sweeping range of reverse bias voltages between two exemplary electrodes 122 and 124 utilizing electrical stimulator-analyzer device 106.
In an exemplary embodiment, steps 406 and 407 of irradiating an exemplary light beam to exemplary sample 129 on graphene-semiconductor Schottky junction 128 and applying an exemplary set of voltages in reverse bias regime to graphene-semiconductor Schottky junction 128 may be done concurrently so that an exemplary set of photocurrents passing through graphene-semiconductor Schottky junction 128 may be generated. As used herein, “photocurrent” may refer to a photo-generated electrical current. In an exemplary embodiment, a photo-generated electrical current may be an electrical current with charge carriers generated due to light irradiation by converting photons to electrons. Herein, irradiating a light beam to an exemplary semiconductor material of graphene-semiconductor Schottky junction 128 may lead to generating a photocurrent passed through graphene-semiconductor Schottky junction 128. In detail, when photons hit a depletion region of graphene-semiconductor Schottky junction 128 while conducting step 406 of irradiating an exemplary light beam to exemplary sample 129 on graphene-semiconductor Schottky junction 128, an amount of energy may be absorbed to graphene-semiconductor Schottky junction 128 and may cause excitation of electrons and creation of electron-hole pairs. Exited electrons and created electron-hole pairs are charge carriers which may be separated (electrons go towards Si and holes towards graphene) due to an electric field (applied in step 407) in graphene-semiconductor Schottky junction 128; thereby, leading to generation of photocurrent in graphene-semiconductor Schottky junction 128.
Referring back to
Additionally, step 404 may include detecting a presence of cancer cells in exemplary sample 129 if a change is detected in an exemplary measured set of generated photocurrents within an exemplary reverse bias regime. In an exemplary embodiment, detecting the presence of cancer cells in exemplary sample 129 may include detecting at least two electrical currents within an exemplary measured set of produced electrical currents being different with each other by a difference magnitude of more than about 10 nA. In an exemplary embodiment, exemplary sample 129 may be detected to be healthy or normal if all electrical current magnitudes of the measured set of produced electrical currents are the same. In an exemplary embodiment, exemplary sample 129 may be detected to be healthy or normal if a difference between magnitudes of each two electrical currents of an exemplary measured set of produced electrical currents is less than about 10 nA.
In an exemplary embodiment, step 407 may include applying two electrical voltages in an exemplary reverse bias regime between two exemplary electrodes 122 and 124; therefore, step 403 may include measuring two respective photocurrents generated responsive to exemplary applied two electrical voltages. Thereafter, detecting a presence of cancer cells in exemplary sample 129 (step 404) may include comparing exemplary two measured photocurrents respective to exemplary two applied electrical voltages with each other and detecting cancer cells in exemplary sample 129 if exemplary two measured photocurrents are different with each other by a value of more than about 10 nA. In an exemplary embodiment, exemplary two applied electrical voltages may include a first voltage of −1 V and a second voltage of −0.05 V.
In an exemplary embodiment, an exemplary method for detecting Glioblastoma cancer cells in an exemplary sample is described.
In detail, step 412 may include putting exemplary sample 129 in contact with graphene side 142 of graphene-semiconductor Schottky junction 128 of biosensor 102 similar to step 401 of exemplary method 400. In an exemplary embodiment, putting exemplary sample 129 in contact with graphene side 142 of graphene-semiconductor Schottky junction 128 of biosensor 102 may include putting exemplary sample 129 on graphene-semiconductor Schottky junction 128. In an exemplary embodiment, exemplary sample 129 may include a sample drawn from a person suspected to have Glioblastoma cancer.
In an exemplary embodiment, step 414 may include irradiating a light beam with a wavelength in a range of about 500 nm to about 900 nm to exemplary sample 129 put on graphene-semiconductor Schottky junction 128 similar to step 406 of exemplary method 405. In an exemplary embodiment, irradiating an exemplary light beam with a wavelength in a range of about 500 nm to about 900 nm to exemplary sample 129 may include irradiating an exemplary light beam with a wavelength of about 600 nm to exemplary sample 129 put on graphene-semiconductor Schottky junction 128. In an exemplary embodiment, irradiating an exemplary light beam with a wavelength in a range of about 500 nm to about 900 nm to exemplary sample 129 may include irradiating an exemplary light beam with a wavelength of about 850 nm to exemplary sample 129 put on graphene-semiconductor Schottky junction 128.
Furthermore, step 416 may include applying two voltages in a range of bias voltages between two electrodes 122 and 124 of biosensor 102. In an exemplary embodiment, a first voltage of about −1 V and a second voltage of about −0.05 V may be applied between two electrodes 122 and 124 of biosensor 102. In an exemplary embodiment, two electrical currents (photocurrents) may be generated due to the applied first voltage and the applied second voltage while irradiating an exemplary light beam in the presence of exemplary sample 129 on graphene-semiconductor Schottky junction 128. In an exemplary embodiment, step 416 may include an exemplary process similar to step 407 of exemplary method 405.
In an exemplary embodiment, step 418 may include measuring the two generated electrical currents utilizing electrical stimulator-analyzer device 106. In an exemplary embodiment, measuring the two generated electrical currents may include measuring a first electrical current generated between two electrodes 122 and 124 responsive to the applied first voltage of about −1 V and a second electrical current generated between two electrodes 122 and 124 responsive to the applied second voltage of about −0.05 V. In an exemplary embodiment, step 418 may include an exemplary process similar to step 403 of exemplary method 400.
Moreover, step 420 may include detecting a presence of Glioblastoma cancer cells in an exemplary sample if a difference between the measured first electrical current and the measured second electrical current is more than about 10 nA. In an exemplary embodiment, step 420 may include comparing the measured first electrical current with the measured second electrical current by calculating a difference between values of the measured first electrical current and the measured second electrical current and detecting the presence of Glioblastoma cancer cells in an exemplary sample if the measured first electrical current and the measured second electrical current are different with each other by a value of 10 nA or more. Furthermore, step 420 may further include detecting an exemplary sample being normal or healthy if a difference between the measured first electrical current and the measured second electrical current is less than about 10 nA. In an exemplary embodiment, an exemplary sample may be detected to be normal or healthy if the measured first electrical current and the measured second electrical current have the same magnitude.
In an exemplary embodiment, exemplary methods 400, 405, and 410 may be utilized as fast and real-time methods for detecting cancer. In an exemplary embodiment, exemplary methods 400, 405, and 410 may be done in less than about one minute. In an exemplary embodiment, exemplary methods 400, 405, and 410 may be done in less than about 30 seconds.
In an exemplary embodiment, exemplary biosensor 102 may be utilized for detecting and differentiating biological cells by recording and monitoring changes in photocurrent generated in graphene-semiconductor Schottky junction 128 of exemplary biosensor 102 in reverse bias. In an exemplary embodiment, changes in photocurrent generated in graphene-semiconductor Schottky junction 128 of exemplary biosensor 102 in reverse bias may be explained and analyzed by an interplay of two different physical mechanisms of operation of exemplary biosensor 102, each more prominent in a particular wavelength range. In an exemplary embodiment, exemplary two different physical mechanisms may include a first mechanism including a shadow effect regime and a second mechanism including a charge transfer effect regime. In an exemplary embodiment, an exemplary first mechanism of shadow effect regime may be activated when a light beam with a wavelength in a first wavelength range is irradiated to biosensor 102, whereas an exemplary second mechanism of charge transfer effect regime may be activated while irradiating a light beam with a wavelength in a second wavelength range to biosensor 102. In an exemplary embodiment, an exemplary second wavelength range may include higher wavelengths than wavelength of an exemplary first wavelength range. In an exemplary embodiment, an exemplary first wavelength range may include wavelength magnitudes of less than a threshold wavelength and an exemplary second wavelength range may include wavelength magnitudes of more than the threshold wavelength. In an exemplary embodiment, an exemplary threshold wavelength may include a wavelength of about 600 nm. In an exemplary embodiment, the threshold wavelength may include a wavelength of 520 nm for Glioblastoma cancer cells. In an exemplary embodiment, an exemplary second wavelength range may include wavelength magnitudes near infrared (IR) window between about 600 nm and 900 nm.
In an exemplary first mechanism of shadow effect regime illustrated in
In an exemplary embodiment, an exemplary second mechanism of charge transfer effect regime is illustrated in
If programmable logic is used, such logic may execute on a commercially available processing platform or a special purpose device. One ordinary skill in the art may appreciate that an embodiment of the disclosed subject matter can be practiced with various computer system configurations, including multi-core multiprocessor systems, minicomputers, mainframe computers, computers linked or clustered with distributed functions, as well as pervasive or miniature computers that may be embedded into virtually any device.
For instance, a computing device having at least one processor device and a memory may be used to implement the above-described embodiments. A processor device may be a single processor, a plurality of processors, or combinations thereof. Processor devices may have one or more processor “cores.”
An embodiment of the present disclosure is described in terms of this example computer system 600. After reading this description, it will become apparent to a person skilled in the relevant art how to implement the invention using other computer systems and/or computer architectures. Although operations may be described as a sequential process, some of the operations may in fact be performed in parallel, concurrently, and/or in a distributed environment, and with program code stored locally or remotely for access by single or multi-processor machines. In addition, in some embodiments the order of operations may be rearranged without departing from the spirit of the disclosed subject matter.
Processor device 604 may be a special purpose or a general-purpose processor device. As will be appreciated by persons skilled in the relevant art, processor device 504 may also be a single processor in a multi-core/multiprocessor system, such system operating alone, or in a cluster of computing devices operating in a cluster or server farm. Processor device 604 may be connected to a communication infrastructure 606, for example, a bus, message queue, network, or multi-core message-passing scheme.
In an exemplary embodiment, computer system 600 may include a display interface 602, for example a video connector, to transfer data to a display unit 630, for example, a monitor. Computer system 600 may also include a main memory 608, for example, random access memory (RAM), and may also include a secondary memory 610. Secondary memory 610 may include, for example, a hard disk drive 612, and a removable storage drive 614. Removable storage drive 614 may include a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory, or the like. Removable storage drive 614 may read from and/or write to a removable storage unit 618 in a well-known manner. Removable storage unit 618 may include a floppy disk, a magnetic tape, an optical disk, etc., which may be read by and written to by removable storage drive 614. As will be appreciated by persons skilled in the relevant art, removable storage unit 618 may include a computer usable storage medium having stored therein computer software and/or data.
In alternative embodiments, secondary memory 610 may include other similar means for allowing computer programs or other instructions to be loaded into computer system 600. Such means may include, for example, a removable storage unit 622 and an interface 620. Examples of such means may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM, or PROM) and associated socket, and other removable storage units 622 and interfaces 620 which allow software and data to be transferred from removable storage unit 622 to computer system 600.
Computer system 600 may also include a communications interface 624. Communications interface 624 allows software and data to be transferred between computer system 600 and external devices. Communications interface 624 may include a modem, a network interface (such as an Ethernet card), a communications port, a PCMCIA slot and card, or the like. Software and data transferred via communications interface 624 may be in the form of signals, which may be electronic, electromagnetic, optical, or other signals capable of being received by communications interface 624. These signals may be provided to communications interface 624 via a communications path 626. Communications path 626 carries signals and may be implemented using wire or cable, fiber optics, a phone line, a cellular phone link, an RF link or other communications channels.
In this document, the terms “computer program medium” and “computer usable medium” are used to generally refer to media such as removable storage unit 618, removable storage unit 622, and a hard disk installed in hard disk drive 612. Computer program medium and computer usable medium may also refer to memories, such as main memory 608 and secondary memory 610, which may be memory semiconductors (e.g. DRAMs, etc.).
Computer programs (also called computer control logic) are stored in main memory 608 and/or secondary memory 610. Computer programs may also be received via communications interface 624. Such computer programs, when executed, enable computer system 600 to implement different embodiments of the present disclosure as discussed herein. In particular, the computer programs, when executed, enable processor device 604 to implement the processes of the present disclosure, such as the operations in methods 400 and 410 illustrated by
Embodiments of the present disclosure also may be directed to computer program products including software stored on any computer useable medium. Such software, when executed in one or more data processing device, causes a data processing device to operate as described herein. An embodiment of the present disclosure may employ any computer useable or readable medium. Examples of computer useable mediums include, but are not limited to, primary storage devices (e.g., any type of random access memory), secondary storage devices (e.g., hard drives, floppy disks, CD ROMS, ZIP disks, tapes, magnetic storage devices, and optical storage devices, MEMS, nanotechnological storage device, etc.).
In this example, an exemplary biosensor similar to biosensor 102 was fabricated via a process similar to a process according to exemplary method 200 described hereinabove and schematically illustrated in
In this example, a method similar to exemplary methods 400 and 410 utilizing a fabricated biosensor (similar to biosensor 102) of Example 1 hereinabove was used to detect and differentiate Glioblastoma cancer cells from each other and from normal (healthy) cells. Glioma cell line U87MG (IBRC C10982), Glioma cell line T98G, and healthy human fibroblast cells were provided and STR DNA Profiling Analysis was performed to authenticate of Glioma cell lines. Cells were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 100 U/ml penicillin and 100 g/ml streptomycin plus 10% fetal bovine serum (FBS). Cells were incubated at 37° C. in a humidified atmosphere containing 5% CO2 until 90% confluency was reached. In order to coat exemplary fabricated biosensors similar to sensor 102 by cells similar to each of steps 401 and 412, approximately 1.2×106 of each cell lines and human fibroblast were suspended in 1 ml phosphate buffer saline and poured gently on the biosensors which were placed on the bottom of 6 respective well plates in duplicate. The plates were incubated at 37° C. in a humidified atmosphere containing 5% CO2. Controls of cell growth and confluency were wells which were coated by each of the cell lines and human fibroblast. By the time the control wells have reached 90% confluency, the cell coated biosensors were removed from each well and were used in photocurrent tests. Silicon epoxy containers were used to isolate exemplary graphene layers of the biosensors and to act as a barrier to hold an exemplary solution containing the cells. All biosensors were characterized in dark and also under irradiation by different wavelengths of light before the addition of cells. The cells were added to the epoxy containers that were created to hold the cell solution, and during tests, these wells were filled with PBS solutions. These tests were carried out similar to steps 404-408 and/or 414-420 and repeated in the presence of different cell lines, and changes in photocurrent were recorded for comparison. High quality commercial 3W LEDs were used as light sources with peak intensities in 380 nm, 425 nm, 520 nm, 620 nm, 740 nm and 850 nm for irradiating a light beam to cells adhered to an exemplary graphene/Si Schottky junction of an exemplary fabricated biosensor similar to each of steps 401 and 412.
Healthy human fibroblast cells were also tested to determine behavior of an exemplary biosensor in the presence of healthy cells.
As described hereinabove referring to
To better demonstrate sensitivity and selectivity of an exemplary biosensor, amperometric tests were performed under a reverse bias voltage of −1 V.
To better quantify the results, relative photocurrent change (RPC) in the reverse bias is plotted in
On the other hand, the U87 cell line in the IR window shows a marked increase in RPC relative to the device with T98G cells. This suggests the existence of local regions with lower Schottky barriers where the cells have adhered to the graphene. This increases the electron emission from graphene to Si in these regions. The different behavior of the two Glioblastoma cancer cell lines can be used to identify and differentiate between U87 and T98G cell lines.
It should also be noted that the T98 cell line comes from a 61 years old male patient, which has no tumorigenic ability. Tumorigenicity is the tendency of cultured cells to develop benign or malignant growing tumors when injected to an immunologically unresponsive animal. U87 cell line is reported to come from a male patient of unknown age, which has tumorigenic ability. U87 cells were significantly more invasive, compared to the T98G cell line.
While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.
Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.
The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101, 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.
Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent to the public, regardless of whether it is or is not recited in the claims.
It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “a” or “an” does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments. This is for purposes of streamlining the disclosure, and is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
While various embodiments have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and embodiments are possible that are within the scope of the embodiments. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any embodiment may be used in combination with or substituted for any other feature or element in any other embodiment unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.
This application is a continuation-in-part of International Patent Application PCT/IB2022/054230, filed on May 6, 2022, and entitled “CANCER CELL DETECTION BY MONITORING CHANGES IN PHOTORESPONSE OF GRAPHENE/SILICON SCHOTTKY DIODE”, which takes priority from U.S. Provisional Patent Application Ser. No. 63/298,666, filed on Jan. 12, 2022, and entitled “GRAPHENE/SILICON SCHOTTKY JUNCTION BASED DEVICE FOR CANCER CELL ANALYSIS”, which are both incorporated herein by reference in their entirety.
Number | Date | Country | |
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63298666 | Jan 2022 | US |
Number | Date | Country | |
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Parent | PCT/IB22/54230 | May 2022 | US |
Child | 18099103 | US |