Functionalized Titanium Dioxide Nanoparticle-Based Electrochemical Immunosensor for Detection of SARS-CoV-2 Antibody

Abstract

The advancement in biosensors can overcome the challenges faced by conventional diagnostic techniques for the detection of the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Hence, the development of an accurate, rapid, sensitive, and selective diagnostic technique can mitigate adverse health conditions caused by SARS-CoV-2. This work proposes the development of an electrochemical immunosensor based on bio-nanocomposites for the sensitive detection of SARS-CoV-2 antibodies through the differential pulse voltammetry (DPV) electroanalytical method. The facile synthesis of chitosan-functionalized titanium dioxide nanoparticles (TiO2-CS bio-nanocomposites) is performed using the sol-gel method. Characterization of the TiO2-CS bio-nanocomposite is accomplished using UV-vis spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The electrochemical performance is studied using cyclic voltammetry (CV), DPV, and electrochemical impedance spectroscopy (EIS) for its electroanalytical and biosensing capabilities. The developed immunosensing platform has a high sensitivity with a wide range of detection from 50 ag mL−1 to 1 ng mL−1. The detection limit of the SARS-CoV-2 antibody in buffer media is obtained to be 3.42 ag mL−1 and the limit of quantitation (LOQ) to be 10.38 ag mL−1. The electrochemical immunosensor has high selectivity in different interfering analytes and is stable for 10 days. The results suggest that the developed electrochemical immunosensor can be applicable for real sample analysis and further high-throughput testing.

Nanoparticles in Electrochemical Immunosensors – A Concept and Perspective

“…[110] As the literature shows, NPs for electrochemical immunosensing applications were also synthesized starting from semiconductor materials, such as Iron oxide, Copper oxide, and Titanium Oxide. [60,[112][113][114][115][116] Among them, Iron oxide NPs are surely the most significant group.…”

“…[59] Furthermore, MOFs and COFs were also differently used. [57,58] Several MeONPs are employed accordingly to conventional MeNPs, such as TiO 2 , [60] CeO 2 [61] or Cu 2 O. [62] In this regard, Fe 3 O 4 NPs represent a highly versatile category of NPs, satisfying the need for ET promotion, effective Ab immobilization and simplicity in separating the analyte simultaneously.…”

Internet‐of‐medical‐things integrated point‐of‐care biosensing devices for infectious diseases: Toward better preparedness for futuristic pandemics

“…The platform was even validated to detect SARS‐CoV‐2 infection in nasopharyngeal swab specimens of COVID‐19 patients 123 . Furthermore, chitosan‐functionalized titanium dioxide nanoparticles (TiO 2 ‐CS bio‐nanocomposites) modified glassy carbon electrodes have been studied for the fabrication of electrochemical immunosensor for the detection of SARS‐CoV‐2 antibodies with a remarkable enhancement in detection limit up to 3.42 ag ml −1 in buffer samples 124 …”

Immunosensors for Assay of Toxic Biological Warfare Agents

“…Immunosensors are a variant of a biosensor where an antibody plays the role of a biorecognition element, and an antigen is an analyte [ 43 , 44 , 45 , 46 , 47 ]. Conception in which an immunosensor containing an antibody is detected by an antigen is possible as well [ 48 ]. Toxins assay by an immunosensor can work on a direct interaction between immobilized antibodies specific to the toxin and the toxin itself presented in the sample.…”