Electrochemical Immunoassay for Capturing Capsular Polysaccharide of Burkholderia pseudomallei: Early Onsite Detection of Melioidosis.

This study presented the detection and quantification of capsular polysaccharide (CPS) as a biomarker for the diagnosis of melioidosis. After successfully screening four monoclonal antibodies (mAbs) previously determined to bind CPS molecules, the team developed a portable electrochemical immunosensor based on antibody-antigen interactions. The biosensor was able to detect CPS with a wide detection range from 0.1pg/mL to 1 µg/mL. The developed biosensor achieved high sensitivity for the detection of CPS spiked into both urine and serum. The developed assay platform was successfully programmed into a Windows app, and the sensor performance was evaluated with different spiked concentrations. The rapid electro-analytical device (READ) sensor showed great unprecedented sensitivity for the detection of CPS molecules in both serum and urine, and results were cross-validated with ELISA methods.

COVID severity test (CoST sensor)-An electrochemical immunosensing approach to stratify disease severity.

With the evolution of the COVID-19 pandemic, there is now a need for point-of-care devices for the quantification of disease biomarkers toward disease severity assessment. Disease progression has been determined as a multifactor phenomenon and can be treated based on the host immune response within each individual. CoST is an electrochemical immunosensor point-of-care device that can determine disease severity through multiplex measurement and quantification of spike protein, nucleocapsid protein, D-dimer, and IL-2R from 100 µL of plasma samples within a few minutes. The limit of detection was found to be 3 ng/mL and 21 ng/mL for S and N proteins whereas for D-dimer and IL-2R it was 0.0006 ng/mL and 0.242 ng/mL, respectively. Cross-reactivity of all the biomarkers was studied and it was found to be <20%. Inter and intra-assay variability of the CoST sensor was less than <15% confirming its ability to detect the target biomarker in body fluids. In addition, this platform has also been tested to quantify all four biomarkers in 40 patient samples and to predict the severity index. A significant difference was observed between healthy and COVID-19 samples with a p-value of 0.0002 for D-dimer and <0.0001 for other proteins confirming the ability of the COST sensor to be used as a point of care device to assess disease severity at clinical sites. This device platform can be modified to impact a wide range of disease indications where prognostic monitoring of the host response can be critical in modulating therapy.

Multiplex sensing of IL-10 and CRP towards predicting critical illness in COVID-19 infections.

Here we present a sensitive method for the detection and quantification of two (IL -10 and CRP) immuno-responsive biomarkers in various biofluids. The significance of these immune response biomarkers lies in them displaying elevated levels in critically ill COVID -19 patients. The developed electrochemical sensor contains a gold film electrode with ZnO nanoparticles deposited on its surface to increase the surface area of the working electrode while integrating antibody-antigen interactions into the detection system. This multiplex biosensor has a wide linear range from 0.01 µg/mL to 100 µg/mL and 0.1 pg/mL to 1000 pg/mL for CRP and IL10, respectively. The cross-reactivity of this multiplex sensor platform was evaluated between these two proteins and was <20%. Recovery studies were performed by spiking known concentrations in serum and urine samples. The recovery was calculated and ranged from 80% to 100%, confirming clinical applicability. This electrochemical sensing platform can aid in the early screening of COVID -19 patients to monitor for the development of more serious and potentially lethal symptoms.

"Nano": An Emerging Avenue in Electrochemical Detection of Neurotransmitters.

The growing importance of nanomaterials toward the detection of neurotransmitter molecules has been chronicled in this review. Neurotransmitters (NTs) are chemicals that serve as messengers in synaptic transmission and are key players in brain functions. Abnormal levels of NTs are associated with numerous psychotic and neurodegenerative diseases. Therefore, their sensitive and robust detection is of great significance in clinical diagnostics. For more than three decades, electrochemical sensors have made a mark toward clinical detection of NTs. The superiority of these electrochemical sensors lies in their ability to enable sensitive, simple, rapid, and selective determination of analyte molecules while remaining relatively inexpensive. Additionally, these sensors are capable of being integrated in robust, portable, and miniaturized devices to establish point-of-care diagnostic platforms. Nanomaterials have emerged as promising materials with significant implications for electrochemical sensing due to their inherent capability to achieve high surface coverage, superior sensitivity, and rapid response in addition to simple device architecture and miniaturization. Considering the enormous significance of the levels of NTs in biological systems and the advances in sensing ushered in with the integration of nanotechnology in electrochemistry, the analysis of NTs by employing nanomaterials as interface materials in various matrices has emerged as an active area of research. This review explores the advancements made in the field of electrochemical sensors for the sensitive and selective determination of NTs which have been described in the past two decades with a distinctive focus on extremely innovative attributes introduced by nanotechnology.