Biosensor

Here we provide data from a head-to-head comparison study using four biosensor platforms: GE Healthcare׳s Biacore T100, Bio-Rad׳s ProteOn XPR36, ForteBio׳s Octet RED384, and Wasatch Microfluidics׳s IBIS MX96. We used these instruments to analyze the binding interactions of a panel of ten high-affinity monoclonal antibodies with their antigen, human proprotein convertase subtilisin kexin type 9 (PCSK9). For each instrument, binding curves obtained at multiple densities of surface antibodies were fit to the 1:1 Langmuir kinetic model, and the association and dissociation rate constants and corresponding affinity constants were calculated. The data supplied in this article accompany the research article entitled, "Comparison of biosensor platforms in the evaluation of high affinity antibody-antigen binding kinetics" (Yang et al., 2016) [1], which further discusses the strengths and weaknesses of each biosensor platform with an emphasis on data consistency, comparability, and ...

The acquisition of reliable kinetic parameters for the characterization of biomolecular interactions is an important component of the drug discovery and development process. While several benchmark studies have explored the variability of kinetic rate constants obtained from multiple laboratories and biosensors, a direct comparison of these instruments' performance has not been undertaken, and systematic factors contributing to data variability from these systems have not been discussed. To address these questions, a panel of ten high-affinity monoclonal antibodies was simultaneously evaluated for their binding kinetics against the same antigen on four biosensor platforms: GE Healthcare's Biacore T100, Bio-Rad's ProteOn XPR36, ForteBio's Octet RED384, and Wasatch Microfluidics's IBIS MX96. We compared the strengths and weaknesses of these systems and found that despite certain inherent systematic limitations in instrumentation, the rank orders of both the associa...

An ultrasensitive electrochemical aptasensor was designed with a bifunctionalized conducting polymer nanobioconjugate to monitor patients' progress in cancer immunotherapy by detecting IFN-γ. The sensing probe was fabricated by covalently immobilizing aptamer on a polyterthiophene benzoic acid composited with multi-walled carbon nanotube/Au nanoparticles. The nanobioconjugate was prepared through the self-assembly of bifunctionalized terthiophene aminobenzoic acid (TABA) onto AuNPs then covalently attached with a redox indicator and an antibody on the amine and carboxyl groups of TABA, respectively. At the optimized condition, the sensor detected IFN-γ in the concentration range of 0.5 fM-100 pM with a detection limit of 0.46 ± 0.006 fM (RSD ≤5.1%). The sensor was applied to monitor the extracellular release of IFN-γ by peripheral blood mononuclear cells and the IFN-γ levels in patients' serum before and after immunotherapy. We observed a low concentration of 0.07 ± 0.004 pM (RSD ≤5.6%) before therapy, which increased significantly to 0.43 ± 0.02 pM (RSD ≤5.1%) after immunotherapy. Meanwhile, a high IFN-γ level of 0.67 ± 0.04 pM (RSD ≤6.2%) was detected in healthy controls. In addition, our study showed IFN-γ is a more effective biomarker for predicting patients' response to blockade therapy as compared to granzyme B.

Lung cancer is among the most life-threatening diseases, as it is by far the leading cause of death around the globe. However, plentiful studies have been reported with satisfactory results employing electrochemical biosensors, which make this method popular in lung cancer diagnosis. In assembling the sensing platforms, different materials of the sensor interfaces are utilized in electrode surface modification to enhance performance. A natural biopolymer chitosan (CS) is an outstanding material for the development of electrochemical biosensors. The unique physiochemical features exhibited by CS facilitate the preservation of its innovative traits and promote its secure adhesion onto the electrode surface. It also has inherent characteristics, such as high adsorption ability, good biocompatibility, eco-friendliness nature, greater heat stability, improved permeability, mechanical potency, outstanding layer-forming capability, and ease of availability. In combination with conductive materials, CS enables the modified electrodes to perform the best analytical results. This review is focused on the importance of CS in sensor configuration, advancements of CS-based electrochemical biosensors for detecting lung cancer biomarkers, and future prospects.

The control of uric acid is important. A high level of uric acid can cause gout disease. Therefore a simple, fast, and accurate method for uric acid determination is required. In this research a conductometric biosensor has been developed by SPCE – Nata de coco for uric acid determination. The prepared biosensor was optimized to get a good performance of biosensor and it is applicable for human serum samples. The optimized variables were enzyme concentration, membrane thickness and pH solution. The various enzyme concentration were 6 μg/mL; 12 μg/mL; 18μg/mL; 24 μg/mL. The various membrane thickness were 5 μm; 10 μm; 15 μm. Meanwhile, the various pH solution were 7; 7.5; 8; 8.5; 9. The optimum enzime concentration was 18 µg/mL with the membrane thickness and pH were 5 µm and 8, respectively. The prepared biosensor can determine the uric acid concentration at range of 0 – 1.2 ppm with the sensitivity of 7.74 µS/ppm and the limit detection is 0 ppm. The biosensor was applied to uric a...

Surface plasmon resonance-based biosensors are now acknowledged as robust and reliable instruments to determine the kinetic parameters related to the interactions between biomolecules. These kinetic parameters are used in screening campaigns: there is a considerable interest in reducing the experimental time, thus improving the throughput of the surface plasmon resonance assays. Kinetic parameters are typically obtained by analyzing data from several injections of a given analyte at different concentrations over a surface where its binding partner has been immobilized. It has been already proven that an iterative optimization approach aiming at determining optimal analyte injections to be performed online can significantly reduce the experimentation time devoted to kinetic parameter determination, without any detrimental effect on their standard errors. In this study, we explore the potential of this iterative optimization approach to further reduce experiment duration by combining ...

The aim of the present work was the development of a novel amperometric biosensor for rapid detection of sucrose in fruit juices samples. Two enzymes, invertase and fructose dehydrogenase (FDH), were immobilized onto a single-walled carbon nanotube paste (SWCNTP) electrode by wiring with a highly original osmium-polymer hydrogel. A second biosensor, for fructose only, was constructed containing inactive invertase and used for signal subtraction. The biosensor exhibits a detection limit for sucrose of 2 mM, linearity up to 5 mM, good sensitivity of 1.98 mA cm-2 mM, good reproducibility (RSD = 2.5%), fast response time (8s) and a stability of 4 months if kept under wet conditions at 4 °C. The biosensor was successively tested for specific detection of sucrose and fructose in several commercial fruit juice samples and the results were compared with those obtained with a commercial spectrophotometric enzymatic kit.

An innovative electrochemical biosensor based on graphene quantum dots (GQDs) is developed for a simple, rapid, and highly sensitive primary diagnosis of the breast cancer biomarker cluster of differentiation-44 (CD44) antigen. Herein, electrochemical exfoliation of waste dry batteries provides facile, eco-friendly, and cost-effective synthesis of GQDs. Transmission electron microscopy (TEM) analysis reveals that GQDs exhibit spherical shapes with an average diameter of 4.75 nm. Further, electrochemical analysis through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) reveals that the electrochemical properties of GQDs are suitable for biosensing applications. Subsequently, GQDs have a large electroactive surface area that has been utilized for the immobilization of CD44 antibodies to fabricate the electrochemical biosensor. The electroanalytical performance of GQDs for CD44 biosensing capabilities is studied by differential pulse voltammetry (DPV). The devel...

Cancer is a life-threatening disease, which is rapidly becoming a global pandemic. Driven by this need, here we report for the first time an aptamer-conjugated theranostic magnetic hybrid graphene oxide-based assay for highly sensitive tumor cell detection from blood samples with combined therapy capability. AGE-aptamer-conjugated theranostic magnetic nanoparticle-attached hybrid graphene oxide was developed for highly selective detection of tumor cells from infected blood samples. Experimental data indicate that hybrid graphene can be used as a multicolor luminescence platform for selective imaging of G361 human malignant melanoma cancer cells. The reported results have also shown that indocyanine green (ICG)-bound AGE-aptamer-attached hybrid graphene oxide is capable of combined synergistic photothermal and photodynamic treatment of cancer. Targeted combined therapeutic treatment using 785 nm near-infrared (NIR) light indicates that the multimodal therapeutic treatment is highly e...

The endocrine-disrupting chemicals affect the functioning of hormones of animals and are called ``environmental hormones". They exist in various environments at very low concentrations in the range of ppt to ppb levels. Thus, highly sensitive determination of environmental hormones with high selectivity is indispensable in regulating the ecosystem, and the instrumentation that allows the on-site analysis of environmental hormones is

Retinol-binding protein 4 (RBP4) has been implicated in insulin resistance in rodents and humans with obesity and T2DM, making it a potential biomarker for the early diagnosis of T2DM. However, diagnostic tools for low-level detection of RBP4 are still lagging behind. Therefore, there is an urgent need for the development of T2DM diagnostics that are rapid, cost-effective and that can be used at the point-of-care (POC). Recently, nano-enabled biosensors integrating highly selective optical detection techniques and specificity of aptamers have been widely developed for the rapid detection of various targets. This study reports on the development of a rapid gold nanoparticles (AuNPs)-based aptasensor for the detection of RBP4. The retinol-binding protein aptamer (RBP-A) is adsorbed on the surface of the AuNPs through van der Waals and hydrophobic interactions, stabilizing the AuNPs against sodium chloride (NaCl)-induced aggregation. Upon the addition of RBP4, the RBP-A binds to RBP4 a...

A facile and label-free detection method based on the formation of the G-quadruplex structure of Thioflavin T and a DNA sequence was developed for rapid and sensitive detection of copper (Cu 2+) ion. The DNA sequence with many guanine (G) repeats has the potential to form a G-quadruplex structure and exhibits high selectivity to Cu 2+. ThT promotes the formation of the G-quadruplex structure resulting in high fluorescence intensity because of its fluorescence molecular rotor characteristic. As opposed to, when the DNA sequence binds to its target in the presence of Cu 2+ , conformational changes occur, resulting in ThT dissociation and a substantial decrease in fluorescence intensity. By virtue of this change, unlabeled, low-cost, sensitive, and selective detection of Cu 2+ was achieved and not interfered by many other ions. The proposed method has high sensitivity and selectivity, with a detection limit of 30.7 nM, allowing it to directly measure Cu 2+ in contaminated water samples in a wide linear range from 0.1 to 100 µM with a high recovery rate.

An overview is presented which summarizes our accomplishment in the development of sensors and biosensors based on heterogenous carbon electrodes modified with manganese dioxide. Brief account of each sensor and biosensor has been given and example of real sample applications provided where appropriate.