Graphene Nano-Biosensors for Detection of Cancer Risk

Biosensor diagnostics based on bio-functionalized semiconductor devices are an important development in ultrasensitive sensors for early detection of disease biomarkers. Electrochemical devices using chemically modified graphene (CMG) channels are excellent candidates for nanobiosensors. This paper presents the development of novel antibody functionalized epitaxial graphene devices for bio-sensing applications. Epitaxial graphene has been grown on silicon carbide (SiC) substrates under high vacuum and high temperature conditions (1200 – 1700°C). A generic electrochemical surface functionalisation chemistry, which can be used to attach a variety of “bio-receptors” to graphitic surfaces, has been developed. The attached bio-receptors are capable of specific and selective interaction with disease biomarkers. When a target biomarker molecule interacts with the “bio-receptor” functionalized surface, the charge density at that surface is affected. This change can be detected as an electrical signal from the biosensor, enabling highly sensitive (nM) detection of biomarker analytes. This paper reports the fabrication of graphene channel sensors for detection of disease biomarkers.

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Recent Advances in Quenchbody, a Fluorescent Immunosensor

Sensors ◽

10.3390/s21041223 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1223

Author(s):

Jinhua Dong ◽

Hiroshi Ueda

Keyword(s):

Fluorescence Intensity ◽

Fluorescent Dyes ◽

Antibody Fragment ◽

Disease Diagnosis ◽

Disease Biomarkers ◽

Highly Sensitive ◽

Physiologically Active Substances ◽

New Type ◽

Antigen Antibody ◽

Active Substances

The detection of viruses, disease biomarkers, physiologically active substances, drugs, and chemicals is of great significance in many areas of our lives. Immunodetection technology is based on the specificity and affinity of antigen–antibody reactions. Compared with other analytical methods such as liquid chromatography coupled with mass spectrometry, which requires a large and expensive instrument, immunodetection has the advantages of simplicity and good selectivity and is thus widely used in disease diagnosis and food/environmental monitoring. Quenchbody (Q-body), a new type of fluorescent immunosensor, is an antibody fragment labeled with fluorescent dyes. When the Q-body binds to its antigen, the fluorescence intensity increases. The detection of antigens by changes in fluorescence intensity is simple, easy to operate, and highly sensitive. This review comprehensively discusses the principle, construction, application, and current progress related to Q-bodies.

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Terahertz quantum sensing

Science Advances ◽

10.1126/sciadv.aaz8065 ◽

2020 ◽

Vol 6 (11) ◽

pp. eaaz8065 ◽

Cited By ~ 11

Author(s):

Mirco Kutas ◽

Björn Haase ◽

Patricia Bickert ◽

Felix Riexinger ◽

Daniel Molter ◽

...

Keyword(s):

Layer Thickness ◽

Region Of Interest ◽

Coherent Detection ◽

Semiconductor Detectors ◽

Terahertz Frequency ◽

Sensing Applications ◽

Highly Sensitive ◽

Quantum Sensing ◽

Thickness Measurements ◽

Detection Schemes

Quantum sensing is highly attractive for accessing spectral regions in which the detection of photons is technically challenging: Sample information is gained in the spectral region of interest and transferred via biphoton correlations into another spectral range, for which highly sensitive detectors are available. This is especially beneficial for terahertz radiation, where no semiconductor detectors are available and coherent detection schemes or cryogenically cooled bolometers have to be used. Here, we report on the first demonstration of quantum sensing in the terahertz frequency range in which the terahertz photons interact with a sample in free space and information about the sample thickness is obtained by the detection of visible photons. As a first demonstration, we show layer thickness measurements with terahertz photons based on biphoton interference. As nondestructive layer thickness measurements are of high industrial relevance, our experiments might be seen as a first step toward industrial quantum sensing applications.

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Hybrid Grating in Reduced-Diameter Fiber for Temperature-Calibrated High-Sensitivity Refractive Index Sensing

Applied Sciences ◽

10.3390/app9091923 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1923

Author(s):

Biqiang Jiang ◽

Zhen Hao ◽

Dingyi Feng ◽

Kaiming Zhou ◽

Lin Zhang ◽

...

Keyword(s):

Refractive Index ◽

Simultaneous Measurement ◽

Surrounding Medium ◽

High Sensitivity ◽

Fiber Grating ◽

Bragg Resonance ◽

Core Mode ◽

Promising Alternative ◽

Sensing Applications ◽

Highly Sensitive

We propose and experimentally demonstrate a hybrid grating, in which an excessively tilted fiber grating (Ex-TFG) and a fiber Bragg grating (FBG) were co-inscribed in a reduced-diameter fiber (RDF). The hybrid grating showed strong resonances due to coupling among core mode and a set of polarization-dependent cladding modes. This coupling showed enhanced evanescent fields by the reduced cladding size, thus allowing stronger interaction with the surrounding medium. Moreover, the FBG’s Bragg resonance confined by the thick cladding was exempt from the change of the surrounding medium’s refractive index (RI), and then the FBG can work as a temperature compensator. As a result, the Ex-TFG in RDF promised a highly sensitive RI measurement, with a sensitivity up to ~1224 nm/RIU near the RI of 1.38. Through simultaneous measurement of temperature and RI, the temperature dependence of water’s RI is then determined. Therefore, the proposed hybrid grating with a spectrum of multi-peaks embedded with a sharp Bragg resonance is a promising alternative for the simultaneous measurement of multi-parameters for many RI-based sensing applications.

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Highly sensitive broadband binary photoresponse in gateless epitaxial graphene on 4H-SiC

Carbon ◽

10.1016/j.carbon.2021.07.098 ◽

2021 ◽

Author(s):

Shivi Rathore ◽

Dinesh Kumar Patel ◽

Mukesh Kumar Thakur ◽

Golam Haider ◽

Martin Kalbac ◽

...

Keyword(s):

Epitaxial Graphene ◽

Highly Sensitive

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Highly sensitive electrochemiluminescent DNA biosensor based on hydrazide-modified graphene quantum dots and hemin/G-quadruplex DNAzyme

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2016.10.031 ◽

2016 ◽

Vol 781 ◽

pp. 351-355 ◽

Cited By ~ 6

Author(s):

Xiaoying Wang ◽

Li Liu ◽

Zhaoyin Wang ◽

Zhihui Dai

Keyword(s):

Quantum Dots ◽

Graphene Quantum Dots ◽

Dna Biosensor ◽

Highly Sensitive ◽

G Quadruplex ◽

Modified Graphene

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Specific detection of biomolecules in physiological solutions using graphene transistor biosensors

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1625010114 ◽

2016 ◽

Vol 113 (51) ◽

pp. 14633-14638 ◽

Cited By ~ 95

Author(s):

Ning Gao ◽

Teng Gao ◽

Xiao Yang ◽

Xiaochuan Dai ◽

Wei Zhou ◽

...

Keyword(s):

Ionic Strength ◽

Real Time ◽

Protein Detection ◽

High Ionic Strength ◽

Polymer Layer ◽

General Strategy ◽

Detection Of Biomolecules ◽

Permeable Polymer ◽

Graphene Devices ◽

Modified Graphene

Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high–ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high–ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.

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Trimodal Waveguide Demonstration and Its Implementation as a High Order Mode Interferometer for Sensing Application

Sensors ◽

10.3390/s19122821 ◽

2019 ◽

Vol 19 (12) ◽

pp. 2821 ◽

Cited By ~ 3

Author(s):

Jhonattan C. Ramirez ◽

Lucas H. Gabrielli ◽

Laura M. Lechuga ◽

Hugo E. Hernandez-Figueroa

Keyword(s):

Free Spectral Range ◽

Point Of Care ◽

Low Cost ◽

High Order Mode ◽

Sio2 Substrate ◽

Polymer Waveguide ◽

Sensing Applications ◽

Highly Sensitive ◽

Different Types ◽

Mode Order

This work implements and demonstrates an interferometric transducer based on a trimodal optical waveguide concept. The readout signal is generated from the interference between the fundamental and second-order modes propagating on a straight polymer waveguide. Intuitively, the higher the mode order, the larger the fraction of power (evanescent field) propagating outside the waveguide core, hence the higher the sensitivity that can be achieved when interfering against the strongly confined fundamental mode. The device is fabricated using the polymer SU-8 over a SiO2 substrate and shows a free spectral range of 20.2 nm and signal visibility of 5.7 dB, reaching a sensitivity to temperature variations of 0.0586 dB/ ∘ C. The results indicate that the proposed interferometer is a promising candidate for highly sensitive, compact and low-cost photonic transducer for implementation in different types of sensing applications, among these, point-of-care.

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