Electrochemical Biosensor for SARS-CoV-2 cDNA Detection Using AuPs-Modified 3D-Printed Graphene Electrodes

Abstract

A low-cost and disposable graphene polylactic (G-PLA) 3D-printed electrode modified with gold particles (AuPs) was explored to detect the cDNA of SARS-CoV-2 and creatinine, a potential biomarker for COVID-19. For that, a simple, non-enzymatic electrochemical sensor, based on a Au-modified G-PLA platform was applied. The AuPs deposited on the electrode were involved in a complexation reaction with creatinine, resulting in a decrease in the analytical response, and thus providing a fast and simple electroanalytical device. Physicochemical characterizations were performed by SEM, EIS, FTIR, and cyclic voltammetry. Square wave voltammetry was employed for the creatinine detection, and the sensor presented a linear response with a detection limit of 0.016 mmol L−1. Finally, a biosensor for the detection of SARS-CoV-2 was developed based on the immobilization of a capture sequence of the viral cDNA upon the Au-modified 3D-printed electrode. The concentration, immobilization time, and hybridization time were evaluated in presence of the DNA target, resulting in a biosensor with rapid and low-cost analysis, capable of sensing the cDNA of the virus with a good limit of detection (0.30 µmol L−1), and high sensitivity (0.583 µA µmol−1 L). Reproducible results were obtained (RSD = 1.14%, n = 3), attesting to the potentiality of 3D-printed platforms for the production of biosensors.

A review on the surface modification of materials for 3D-printed diagnostic devices

“…The use of PLA with graphene has been reported in many studies. [43][44][45][46][47][48] It has been reported that most of them used dimethylformamide (DMF), NaOH, and sulfuric acid treatment for the surface modication. Table 1 shows the different types of materials that are used in 3D printing with their surface modication techniques and applications.…”

Graphene-Based Electrochemical Nano-Biosensors for Detection of SARS-CoV-2

“…A facile, non-enzymatic electrochemical sensor for the detection of SARS-CoV-2 cDNA was developed by Silva et al [62] using a disposable, low-cost graphene polylactic (G-PLA) 3D-printed electrode modified with Au nanoparticles. Through a complex reaction with creatinine, the Au nanoparticles that were deposited on the electrode facilitated a reduction in the analytical response, leading to the development of a fast and straightforward electroanalytical device.…”

A Simplistic Label‐Free Electrochemical Immunosensing Approach for Rapid and Sensitive Detection of Anti‐SARS‐COV‐2 Nucleocapsid Antibodies

“…[3] Electrochemical detection has shown great promise to address the limitations of molecular spectroscopic approaches. A variety of electrochemical biosensors [4] have been developed for the detection of SARS-CoV-2, encompassing immunosensors, [5] aptasensors, [6] and enzymatic [7] sensors. These sensors utilize diverse platforms and substrates such as screenprinted electrodes (SPEs), [8] paper-based systems, [9,10] gold electrodes, [11] test strips, [12] and others, demonstrating rapid and accurate detection of SARS-CoV-2.…”