An Innovative Sandwich Type Biosensor towards Sensitive and Selective Monitoring of 2-Arachidonoylglycerol in Human Plasma Samples Using P(β-CD)-AuNPs-DDT as Amplificant Agent: A New Immuno-Platform for the Recognition of Endocannabinoids in Real Samples

Abstract

In this work, 2-AG was successfully detected in human plasma samples using a new sandwich-type electrochemical immune device based on poly-β-cyclodextrin P(β-CD) functionalized with AuNPs-DDT and toluidine blue. The P(β-CD) ensured the bioactivity and stability of the immobilized 2-AG antibody by providing a broad surface for the efficient immobilization of the biotinylated antibody. To complete the top section of the immunosensor (reporter), an HRP-conjugated antibody of 2-AG (secondary antibody (Ab2)) was attached to the surface of a glassy carbon electrode (GCE) modified by P(β-CD), as well as a primarily biotinylated antibody (Ab1). The biosensor fabrication process was monitored using field-emission scanning electron microscope (FE-SEM) and EDS methods. Using the differential pulse voltammetry technique, the immunosensor was utilized for detection of 2-AG in real samples. The suggested interface increased the surface area, which allowed for the immobilization of a large quantity of anti-2-AG antibody while also improving biocompatibility, stability, and electrical conductivity. Finally, the suggested immunosensor’s limit of quantitation was determined to be 0.0078 ng/L, with a linear range of 0.0078 to 1.0 ng/L. The results showed that the suggested bioassay can be utilized for diagnosis of 2-AG in clinical samples as a unique and ultrasensitive electrochemical biodevice.

Electrochemical and Photoelectrochemical Immunosensors for the Detection of Ovarian Cancer Biomarkers

“…It involves the immobilization of the primary antibody on the surface of a modified electrode followed by incubation with the antigen of interest, and then the introduction of a labelled secondary antibody for the enhancement of signals. Although it is a complex system, the high sensitivity and selectivity, ease of fabrication, and rapid analytic time has made this method attractive [65,105,106].…”

Advances in Amplification Methods for Biosensors

“…The high surface coverage of antibodies brought by the nano-particles ensures the sensitive detection of -synuclein, a Parkinson’s disease biomarker [ 7 ]. In the second study, gold nano-particles are grafted on the surface to serve as a signal amplifier in sandwich-type immunno-sensors for the detection of the endocannabinoid 2-AG [ 8 ].…”