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An ultra-sensitive and rapid immunosensor for the onsite detection of circulating tumor DNA in breast cancer

FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY 2024年 12卷 1412598页

作者： Bi, Yi Lv, Xiao Wang, Ke Wu, Jinyu Shi, Xiang Zheng, Xiaodong Lin, Xiaogang Chongqing Univ Chongqing Univ Canc Hosp Chongqing Peoples R China Chongqing Univ Key Lab Optoelect Technol & Syst Minist Educ China Chongqing Peoples R China Chongqing Key Lab Translat Res Canc Metastasis & I Chongqing Peoples R China Chenjiaqiao Hosp Chongqing Med & Pharmaceut Coll Affiliated Hosp Chongqing Peoples R China

Breast cancer currently stands as the most prevalent form of cancer worldwide and the primary cause of cancer-related deaths among women. However, the current diagnostic methods for breast cancer exhibit several limitations, including invasiveness, high costs, and limited sensitivity and specificity. The detection of the PIK3CA-H1047R variant is of paramount importance due to its close association with tumor growth and treatment resistance. Consequently, developing a straightforward, rapid, and highly sensitive approach for detecting PIK3CA-H1047R is of utmost importance. We have been working on the development of a rapid and ultrasensitive biosensor, leveraging the alternating current (AC) electrokinetic (ACEK) capacitive sensing method. This biosensor involves modifying the surface of interdigital electrodes with antibodies, facilitating the antibody-antigen-binding process through AC electrokinetic techniques. Our sensor strategy directly measures the interface capacitance, and the rate of change serves as a quantitative marker for event identification. Remarkably, our biosensor successfully detects the PIK3CA-H1047R antigen within a concentration range of 1 ng/mL to 1 mu g/mL. In conclusion, this study proposes a fast and highly sensitive biosensor for the detection of a key breast cancer marker, the PIK3CA-H1047R variant. This technology is expected to improve breast cancer diagnosis, address the limitations of current methods, and provide patients with better treatment options. This detection method offers a promising avenue for on-site and real-time sensitive detection of the PIK3CA-H1047R antigen, potentially revolutionizing breast cancer diagnosis.

关键词： affinity sensor capacitive biosensor circulating tumor DNA PIK3CA-H1047R alternating current electrokinetics

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Glucose measurement by affinity sensor and pulsed measurements of fluidic resistances: Proof of principle

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Journal of Diabetes Science and Technology 2014年第1期8卷 100-108页

作者： Beyer, Uwe Wyss, Thomas Robin, Franck Heinemann, Lutz Sensile Medical AG CH-4614 Hägendorf Fabrikstr 10 Switzerland Profil Institut für Stoffwechselforschung GmbH Neuss Germany

affinity sensors for glucose are based on a different measuring principle than the commercially available amperometric needle type sensors: reversible affinity interaction of glucose with specific receptors is the primary recognition mechanism instead of an enzymatic glucose oxidation. A novel pulsed-flow micro-fluidic system was used to characterize first the viscosity of a sensitive liquid containing the glucose receptor Concanavalin A and dextran and in a second approach to characterize the geometry of a fluidic resistance. In the viscometric sensor, glucose of the sensitive liquid is equilibrated, while passing through a dialysis chamber, with the surrounding medium. With the membrane flow sensor, the viscosity of the liquid remains constant but the pores of the flow-resisting membrane contain a swellable hydrogel affecting the width of the pores. Two types of hydrogel were tested with the membrane flow sensor;one is highly sensitive to pH and salt concentration, the other contains receptors of phenyl boronic acids to obtain sensitivity to glucose. The viscometric affinity sensor (first approach) showed a linear response over 0 to 30 mmol/L glucose concentration range. The disturbing effect of air bubbles could be compensated for. The sensing proof of principle of the second approach could be demonstrated by its linear response to different saline concentrations;however, the glucose-sensitive membrane developed showed only a small response to glucose. Glucose monitoring based on this pulsed flow measuring principle offers interesting alternatives for the development of CGM systems with different options for the glucose sensing part. © 2014 Diabetes Technology Society.

关键词： affinity sensor Fluidic resistance Glucose monitoring Pressure relaxation

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A label-free fiber-optic Turbidity affinity sensor (TAS) for continuous glucose monitoring

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BIOsensorS & BIOELECTRONICS 2014年 61卷 280-284页

作者： Dutt-Ballerstadt, Ralph Evans, Colton Pillai, Arun P. Gowda, Ashok BioTex Inc Houston TX 77054 USA

In this paper, we describe the concept of a novel implantable fiber-optic Turbidity affinity sensor (TAS) and report on the findings of its in-vitro performance for continuous glucose monitoring. The sensing mechanism of the TAS is based on glucose-specific changes in light scattering (turbidity) of a hydrogel suspension consisting of small particles made of crosslinked dextran (Sephadex G100), and a glucose-and mannose-specific binding protein - Concanavalin A (ConA). The binding of ConA to Sephadex particles results in a significant turbidity increase that is much greater than the turbidity contribution by the individual components. The turbidity of the TAS was measured by determining the intensity of light passing through the suspension enclosed within a small semi-permeable hollow fiber (OD: 220 mu m, membrane thickness: 20 pm, molecular weight cut-off: 10 kDa) using fiber optics. The intensity of measured light of the TAS was proportional to the glucose concentration over the concentration range from 50 mg/dL to 400 mg/dL in PBS and whole blood at 37 degrees C (R > 0.96). The response time was approximately 4 min. The stability of the glucose response of the TAS decreased only slightly (by 20%) over an 8-day study period at 37 degrees C. In conclusion, this study demonstrated proof-of-concept of the TAS for interstitial glucose monitoring. Due to the large signal amplitude of the turbidity change, and the lack of need for wavelength-specific emission and excitation filters, a very small, robust and compact TAS device with an extremely short optical pathlength could be feasibly designed and implemented for invivo glucose monitoring in people with diabetes. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Continuous glucose monitoring affinity sensor Turbidity Concanavalin A Dextran Fiber-optics

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Tailoring the pore accessibility using proteins in laser induced porous graphitic structures: Correlating the physicochemical & electrochemical characteristics

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ELECTROCHIMICA ACTA 2024年 483卷

作者： Suresh, Raghavv Raghavender Dutta, Gorachand Indian Inst Technol Kharagpur Sch Med Sci & Technol NanoBiosensors & Biodevices Lab Kharagpur 721302 India

While the popular means of enhancing the sensor's electroanalytical performance involves novel nanomaterial modifications and functionalization, these are multistep procedures which require several material/electrode characterization studies and are resource intensive. Alternatively, the sensor's performance can also be greatly enhanced by appropriately choosing the electroanalytical technique and by tuning its associated parameters. While such optimization has been popularly addressed via one -parameter -at -a -time strategies, this method demands greater number of experiments and fails to factor in the interaction between variables. Such issues can be addressed via the DoE multivariate statistical technique, which, however has not been widely employed in the field of electroanalysis. Moreover, there is a significant dearth in DoE based works for optimizing the LIG electrode's electroanalytical performance. Hence, in this work we have performed the DoE, FFD-based SWV technique optimization in bare LIG electrodes and have demonstrated a label -free affinity sensing application. While the optimized parameters significantly improved the output signals, we observed counterintuitive traits of increasing current values with protein loading. Hence, to explain these contrary trends we evaluate the electrochemical and physicochemical traits of model protein, BSA modified LIG electrodes, wherein we report the eccentric porous electrode behavior ensuant upon protein modification, associated with pore accessibility in these electrodes. Subsequently, we attribute the pore accessibility traits to hydrophilicity & steric hindrance aspects, and correlate it to the CPE effects, relaxation times and diffusion resistance. While few LIG -based works have reported such contrary trends in label -free affinity sensing, they have not provided the plausible explanation, and this is the first report to comprehensively elucidate the reasons.

关键词： Porous electrodes Transmission line model Laser induced graphene Design of experiment Square wave voltammetry affinity sensor

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A MIP-based low-cost electrochemical sensor for 2-furaldehyde detection in beverages

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ANALYTICA CHIMICA ACTA 2021年 1142卷 201-210页

作者： Pesavento, M. Merli, D. Biesuz, R. Alberti, G. Marchetti, S. Milanese, C. Univ Pavia Dept Chem Pavia Italy

There is an increasing interest in determining the concentration of furanic compounds naturally formed in food aqueous matrices, by in situ, fast and low-cost methods. A sensor presenting such characteristics is here proposed, and characterized. It is based on a molecularly imprinted polymer (MIP) as a receptor with electrochemical transduction on a screen printed cell (SPC). The molecularly imprinted polymer has been developed for a particular furanic derivative, 2-furaldehyde (2-FAL). The detection bases on the reduction of 2-FAL selectively adsorbed on the polymer layer in contact with the working electrode. The polymer layer is simply formed by in situ polymerization, directly over the SPC and it was characterized by IR, SEM and electrochemical methods. Even if based on an easy and fast preparation procedure, the layer sufficiently adheres to the cell surface giving a reusable sensor. Square wave voltammetry (SWV) was applied as the signal acquisition method. The sensor performance in aqueous solution (NaCl 0.1 M) was tested, obtaining that the dose-response curve is fitted by the Langmuir adsorption isotherm. The sensitivity, and so the limit of detection, were noticeably improved by a chemometric approach based on the Design of experiment method. (optimized conditions: E-step = 0.03 V, E-pulse = 0.066 V, integral = 31 s(-1)). In water solution at pH around neutrality the dynamic range was from about 50 mu M to 20 mM. Similar results were obtained for a white wine containing 12% ethanol, which has been considered as a typical example of beverage possibly containing furhaldehydes. The higher limit of quantification can be modulated by the amount of MIP deposited, while the lower detection limit by the conditions of the electrochemical measurement. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Molecularly imprinted polymer Electrochemical transduction Screen printed cell affinity sensor Furanic compounds Beverages

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An alternating current electrokinetics biosensor for rapid on-site serological screening of Taenia solium cysticercosis infection

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MICROCHIMICA ACTA 2022年第12期189卷 476-476页

作者： Lin, Xiaogang Jiang, Yu Wu, Jie Jayne Eda, Shigetoshi Wan, Nan Chongqing Univ Coll Optoelect Engn Key Lab Optoelect Technol & Syst Minist Educ Chongqing 400044 Peoples R China Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA Univ Tennessee Dept Forestry Wildlife & Fisheries Knoxville TN 37996 USA

Cysticercosis, caused by Taenia solium infection, is a leading cause of acquired epilepsy in many developing countries. Several types of immunoassays have been developed for the detection of Taenia solium infection in both infected humans and livestock animals. However, these methods require central laboratory facilities and are both time- and labor-consuming with longer than desired turnaround time. In this work, we demonstrated that AC electrokinetics (ACEK) capacitive sensing can be used to realize point-of-care immunosensor in general, with the on-site screening of Taenia solium infection as an example here. The sensor employs interdigitated microelectrodes (IDME) functionalized with a recombinant Taenia solium antigen, rT24H, to detect anti-rT24H antibodies in clinical serum samples. ACEK capacitive sensing method interrogates the IDME sensors with a special AC signal, which serves the dual purposes of enriching target antibodies by ACEK effects and directly measuring the capacitance change induced by specific binding. First, to characterize the ACEK biosensor as an immunosensor in general, IgG in phosphate-buffered saline buffer was tested against IDME sensors functionalized with anti-IgG. The limit of detection of the sensor was 24.1 fg/mL, and the linear dynamic range was 0.1-100 pg/mL. To test the clinical usage of this sensor, ACEK capacitive sensors with rT24H probe were used to test clinical serum samples from patients with or without Taenia solium infection. The diagnostic sensitivity of the ACEK capacitive sensor for Taenia solium infection was found to be 88.24%. ACEK capacitive immunosensors have shown good potential for point-of-care diagnostics.

关键词： AC electrokinetics Capacitive sensing affinity sensor Serological diagnosis Point-of-care Taenia solium

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A single-step DNAzyme sensor for ultra-sensitive and rapid detection of Pb²⁺ ions

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ELECTROCHIMICA ACTA 2021年 368卷 137551-137551页

作者： Meng, Jiyu Huang, Jiamei Oueslati, Rania Jiang, Yu Chen, Jiangang Li, Shanshan Dai, Shijie He, Qiang Wu, Jayne Hebei Univ Technol State Key Lab Reliabil & Intelligence Elect Equip Tianjin 300132 Peoples R China Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA Univ Tennessee Dept Publ Hlth Knoxville TN 37996 USA Hebei Univ Technol Sch Mech Engn Tianjin 300401 Peoples R China Hebei Key Lab Smart Sensing & Human Robot Interac Tianjin 300130 Peoples R China Univ Tennessee Dept Civil & Environm Engn Knoxville TN 37996 USA

Effective protection from Pb2+ contamination calls for its rapid detection in environmental and biological samples, including water sources. This work demonstrates a rapid, highly sensitive and specific DNAzyme-based Pb2+ biosensor, which is also the first reported label free bioelectronic sensor for catalytic hydrolysis. The sensors are prepared from gold-plated interdigitated electrodes (IDEs), functionalized with oligonucleotide substrate strands and subsequent hybridization with DNAzyme strands. After sample fluid is applied onto a sensor for detection, the sensor's serial capacitance is continuously interrogated by an optimized alternating current (AC) signal for 15 s. If Pb2+ is present, the DNAzyme catalyzes a cleavage reaction of the substrate, releasing the DNAzyme and substrate fragments into the solution. The reaction leaves partial substrate strand at the sensor surface, causing a change in the IDEs' interfacial capacitance. Another novelty here is that capacitance measurement simultaneously induce a fluidic enrichment effect, AC electrothermal effect, thus concentrating and measuring Pb2+ in a single step. The AC signal is carefully optimized to minimize non-specific collection of macromolecules, including released DNAzyme and substrate fragments. In this work, Pb2+ level can be quantified in 15 s with a detection limit of 1.26 fM and a linear dynamic range from 1 fM to 1 pM in analytical buffer. To demonstrate the sensor's specificity, non-target metal ions are tested, all giving negligible responses. Testing of tap water samples collected under different conditions also yields reasonable results, validating the robustness of this sensor. This rapid and sensitive sensor holds high promise for on-site detection of Pb2+ in practical samples. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Heavy metal ion detection affinity sensor Capacitive sensing AC electrokinetics Interdigitated microelectrodes

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Low-Cost and Desktop-Fabricated Biosensor for Rapid and Sensitive Detection of Circulating D-Dimer Biomarker

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IEEE sensorS JOURNAL 2019年第4期19卷 1245-1251页

作者： Li, Shanshan Jiang, Yu Eda, Shigetoshi Wu, Jie Jayne Univ Tennessee Knoxville TN 37996 USA Univ Tennessee Dept Elect Engn & Comp Sci Knoxville TN 37996 USA Univ Tennessee Inst Agr Dept Forestry Wildlife & Fisheries Knoxville TN 37996 USA

Disposable point-of-care biomedical applications demand low-cost biosensing systems that can provide rapid detection with accessible fabrication requirements and user-friendly operation. Here, we present an easy-to-operate and cleanroom-free desktop-fabricated biosensor that is capable of reliable detection for human D-dimer biomarkers on-site. Interdigitated electrodes are used as the biosensor, and they are fabricated using commercial compact discs and home-made gadgets. The compact disc-based electrode arrays are patterned by wet-etching and followed by electroplating of polypyrrole (PPy). The nano-porous structures of PPy enhance the immobilization of protein probe on the electrode surface. The sensor performance is further enhanced by the ac electrokinetics (ACEK) capacitive sensing method. ACEK capacitive sensing induces ACEK effects that direct analytes toward the electrode surfaces, significantly promoting probe-target binding. Our sensor can quantitatively detect D-dimer biomarkers in 1 min with a limit of detection of 1 pg/mL. In contrast, Nyquist or Bode plots can only qualitatively distinguish positive and negative samples. Furthermore, the total cost of each test, together with the lithography material and compact disk, is only around US. $1, and it is acceptable to be disposable. The sensitive device yields wide-ranging and significant advantages for biomedical and lab-on-a-chip applications for undeveloped areas.

关键词： AC electrokinetics desktop fabrication capacitive sensing surface functionalization affinity sensor

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Graphene-based Electrochemical Biosensor for Impedimetric Detection of miRNAs as Potential Cancer Biomarkers

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JOURNAL OF THE ELECTROCHEMICAL SOCIETY 2020年第16期167卷

作者： Asadi, Hamid Ramasamy, Ramaraja P. Univ Georgia Sch Chem Mat & Biomed Engn Nano Electrochem Lab Athens GA 30602 USA

MicroRNAs (miRNAs) have shown great potential to be used as biomarkers for the screening and clinical diagnosis of cancer. In this study, an electrochemical biosensor based on graphene-modified glassy carbon electrode was developed for the detection of miRNA-21, a well-known biomarker for the early stage of prostate cancer. A novel molecular tethering agent was used for immobilization of single-stranded probe DNA onto the electrode surface. Different parameters related to biosensor fabrication and experimental conditions were optimized to obtain the highest biosensor response. Electrochemical impedance spectroscopy was employed to achieve a sensitive and label-free detection method for miRNA-21 through measuring the change in charge-transfer resistance (R-ct) before and after hybridization. Under the optimal conditions, the biosensor showed a linear impedimetric response between Delta R-ct and logarithm of miRNA-21 concentration ranging from 10(-14) to 10(-8) M with a correlation coefficient of 0.972 and a detection limit of 3 fM. The selectivity of the biosensor was examined against non-complementary miRNA-141. The biosensor showed acceptable reproducibility, regeneration ability and stability as well as remarkable response (recoveries 90%-116%) in real plasma samples. The results indicated that the proposed biosensor could be used as a promising alternative to conventional methods in early clinical and point-of-care cancer diagnosis.

关键词： Cancer biomarker RNA biosensor DNA immobilization affinity sensor Impedance spectroscopy Label-free detection 1-pyrenebutyric acid-N-hydroxysuccinimide ester

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A MECHANICALLY FLEXIBLE APTAMER-BASED GRAPHENE NANOsensor FOR BIOMARKER MONITORING 20

A MECHANICALLY FLEXIBLE APTAMER-BASED GRAPHENE NANOSENSOR FO...

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20th International Conference on Solid-State sensors, Actuators and Microsystems and Eurosensors XXXIII (TRANSDUCERS and EUROsensorS)

作者： Wang, Ziran Hao, Zhuang Zhao, Xuezeng Lin, Qiao Columbia Univ Dept Mech Engn New York NY 10027 USA Harbin Inst Technol Dept Mech Engn Harbin Peoples R China

ISBN: (纸本)9781728120072

This paper presents an aptamer-based graphene field-effect transistor nanosensor, which is fabricated on an ultrathin polyethylene terephthalate film towards the real-time and specific monitoring of biomarkers in biofluids. The nanosensor offers a consistent transconductance, carrier mobility and on/off ratio when undergoing large bending deformations. When coated with a nonionic surfactant, the graphene conducting channel also enables the effective suppression of nonspecific binding. The ultrathin nanosensor is tested on specific and reliable real-time monitoring of TNF-alpha in artificial tears, demonstrating its potential in wearable medical applications and clinical diagnosis.

关键词： Aptamer affinity sensor biomarker field-effect transistor flexible electronics graphene wearable sensors

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