An Effective SARS-CoV-2 Electrochemical Biosensor with Modifiable Dual Probes Using a Modified Screen-Printed Carbon Electrode

Abstract

Due to the severe acute respiratory syndrome coronavirus (SARS-CoV-2, also called coronavirus disease 2019 (COVID-19)) pandemic starting in early 2020, all social activities ceased in order to combat its high transmission rate. Since vaccination combats one aspect for halting the spread of the virus, the biosensor community has looked at another aspect of reducing the burden of the COVID-19 pandemic on society by developing biosensors that incorporate point-of-care (POC) testing and the rapid identification of those affected in order to deploy appropriate measures. In this study, we aim first to propose a screen-printed carbon electrode (SPCE)-based electrochemical biosensor that meets the ASSURED criteria (i.e., affordable, sensitive, specific, user-friendly, rapid, equipment-free, and deliverable) for POC testing, but more importantly, we describe the novelty of our biosensor’s modifiability that uses custom dual probes made from target nucleic acid sequences. Additionally, regarding the sensitivity of the biosensor, the lowest sample concentration was 10 pM (p = 0.0257) without amplification, which might challenge the traditional technique of reverse transcriptase-polymerase chain reaction (RT-PCR). The purpose of this study is to develop a means of diagnostics for the current pandemic as well as to provide an established POC platform for future epidemics.

The critical experimental aspects for developing pathogen electrochemical biosensors: A lesson during the COVID-19 pandemic

“…Apart from the conventional antibody/antigen-based receptors, aptamers (i.e., oligonucleotides) and ACE2 (i.e., human angiotensin-converting enzyme 2) have also been utilized to develop the SARS-CoV-2 electrochemical biosensors. Regarding the former, we found five individual studies that used an aptamer receptor to target different SAR-CoV-2-related biomarkers, including the S1 receptor-binding domain (RDB) [ 52 , 53 ], RNA sequence [ 54 , 55 ], and nucleocapsid protein (NP) [ 27 ] ( Table 2 ). On the other hand, we also found five individual studies that adopted ACE2 as their receptors (or used it as an alternative to the secondary antibodies).…”

“…In many real cases, this feature may become more dispositive than other critical technical performances because the distribution of the point-of-care testing kits depends heavily on precisely coordinated cold-chain logistics, and the less temperature-sensitive aptamer-based biosensors can remarkably ease the burden on the logistical cost. After carefully reading all the SARS-CoV-2 electrochemical aptasensors, we found that four (i.e., 80% of total aptamer-based studies) had undergone sensor stability tests over different time spans at 4 °C (or storage in a refrigerator) [ 27 , 52 , 53 , 55 ]. Among them, Abrego-Martinez et al [ 53 ] reported an outstanding result in the thermal stability test after 21-day storage at 4 °C, in which the impedimetric response of the developed aptasensor only lost 1% of its sensing capability with respect to the freshly prepared one.…”

A Review on Potential Electrochemical Point-of-Care Tests Targeting Pandemic Infectious Disease Detection: COVID-19 as a Reference

“…A dual probe-based amplification-free electrochemical sensing approach was proposed by Pang et al for enhanced sensitivity detection of the SARS-CoV-2 nucleic acid sequence, in which the SPCE electrodes were modified with ssDNA capture probe using streptavidin/biotin and EDC/NHS chemistry, and the mimicked sample sequence was functionalized with FITC detector probe on which an anti-fluorescein antibody (HRP) tag was added [78]. For detection, the SPCE containing the dual probe-attached sample sequence was dipped in a solution of 3,3 ,5,5 -tetramethylbenzidine (TMB) and H 2 O 2 , which generated a current signal to be measured by chronoamperometry method using an Autolab.…”

Inkjet Printing: A Viable Technology for Biosensor Fabrication

“…In Section 3.2, enzyme-based biosensors are reviewed, while in Section 3.3, the discussion related to the non-enzymatic biosensors has been included. Glucose sensor [82] Glucose, glutamate, lactate sensor [83] pH sensor [84] Uric Acid sensor [85] Dopamine detection [86] SARS-CoV-2 [87,88] MERS-CoV [89] Escherichia coli (E. coli) [90] Inkjet Printing Multianalyte (pH, Protein, Glucose) sensor Drop-on-demand (DOD), maskless, can create patterns on non-planar surfaces, well-defined patterning, simple, capacity for mass production [91] Nozzle clogging, highly specified ink formulation, limited resolution Ammonia sensor [92] Pathogen detection [93] Bienzymatic Glucose biosensor [94] Calorimetric sensor/ H 2 O 2 detection [95,96] H 2 O 2 and glucose detection [97] Pressure ulcer detection [98] Wearable biosensor detection system/norovirus detection [99] HIV-related ssDNA detection [100] Multiplexed biosensor [101] Protein detection [102] SARS-CoV-2 detection [103] Table 1. Cont.…”