The optimization of an electrochemical aptasensor to detect RBD protein S SARS-CoV-2 as a biomarker of COVID-19 using screen-printed carbon electrode/AuNP

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus identified as the cause of the Coronavirus Disease 2019 (COVID-19) outbreak. The gold standard for detecting this virus is polymerase chain reaction (PCR). The electrochemical biosensor method can be an alternative method for detecting several biomolecules, such as viruses, because it is proven to have several advantages, including portability, good sensitivity, high specificity, fast response, and ease of use. This study aims to optimize an electro­chemical aptasensor using an AuNP-modified screen-printed carbon electrode (SPCE) with an aptamer to detect RBD protein S SARS-CoV-2. Aptasensors with the streptavidin-biotin system were immobilized on the SPCE/AuNP surface via covalent bonding with linkers to 3-mercaptopropionic acid (MPA) and electrochemically characterized by the [Fe(CN)6]3-/4- redox system using differential pulse voltammetry. The results showed that the immobi­lized aptamer on the SPCE/AuNP electrode surface experienced a decrease in current from 11.388 to 4.623 µA. The experimental conditions were optimized using the Box-Behnken experimental design for the three factors that affect the current response. The results of the optimization of the three parameters are the concentration of aptamer, incubation time of aptamer, and incubation time of RBD protein S SARS-CoV-2, each of which is 0.5 µg/mL, 40 minutes, and 60 minutes, respectively. The RBD protein S SARS-CoV-2 with various concentrations was tested on an electrochemical aptasensor to determine the de­tection limit and quantification limit, and the respective results were 2.63 and 7.97 ng/mL. The electrochemical aptasensor that has been developed in this study can be applied to detect RBD protein S SARS-CoV-2 as a COVID-19 biomarker in a simple, practical, and sensitive way.

An electrochemical membrane-based aptasensor for detection of severe acute respiratory syndrome coronavirus-2 receptor-binding domain

“… Aptasensor Biomarkers Technique Linear range Limit of detection Incubation time Ref. SPCE/Aunano/MPA/ biotinylated aptamer SARS-CoV-2-RBD DPV 10–50 ng/mL 2.63 ng/mL 40 min [61] CB/CSPE combined with Magnetic bead-based immunosensor SARS-CoV-2 nucleocapsid proteinSpike protein DPVDPV 0.01–0.6 µg/mL0.04–10 µg/mL 8 ng/mL19 ng/mL 30 min30 min [62] Pad/Aptamer SARS-CoV-2 nucleocapsid protein SPR 0.5–16 ng/mL 1 ng/mL 110 min [63] Gold electrode/Aptamer-Methylene blue SARS-CoV-2-RBD SWV 10 11 -10 10 – 5 min [2] GCE/Yb-TCPP-4/ Au NPs/ Aptamer Spike protein PEC 0.5–8 μg/mL 72 ng/mL 70 min [64] ITO electrode/CdS QDs- Chitosan/gC 3 N 4 Aptamer SARS-CoV-2-RBD PEC 0.5–32.0 nM 0.12 nM 40 [13] LEGE/NPAOM-Si-S-Au nano -Aptamer SARS-CoV-2-RBD SWV 2.5–40.0 ng/mL(71.5 pM-1.14 nM) 0.8 ng/mL(23 pM) 20 min This work DPV: Differential pulse voltammetry; SPR: Surface plasmon resonance; PEC: photoelectrochemistry; MPA: 3-Mercaptopropionic acid; Cu(OH) 2 NRs: Copper hydroxide nanorods; GCE: Glassy carbon electrode; Au NPs: Gold nanoparticles; Yb-TCPP-4: Two-dimensional metal–organic framework …”

Electrochemical and Bioelectrochemical Sensing Platforms for Diagnostics of COVID-19

“…Taking into account a practical application, it is highly desirable to obtain biosensors and electrochemical sensors with high detection powers in nanograms, fentograms, or even lower concentrations [ 30 , 31 , 32 , 33 , 34 ]. To achieve such sensitivity, several factors should be taken into account so that an electrochemical approach achieves performance comparable to or even better than standard procedures.…”

“…Another approach includes the use of different polymeric matrices containing reactive amino and hydroxyl functional groups that are suitable for immobilizing biomolecules, as well as functional nanomaterials (nanoparticles, carbon nanomaterials, hybrid nanomaterials) [ 46 ]. As a last synthesis step, BSA is often used to avoid nonspecific interactions on the electrode surface, acting as a blocker [ 5 , 30 , 34 , 40 , 42 , 45 ].…”

“…Sari et al reported an electrochemical aptasensor using an AuNP-modified SPCE to detect SARS-CoV-2-RBD [ 34 ]. The authors used the streptavidin-biotin system covalently bonded to the surface of SPCE modified with AuNP with the aid of the ligand 3-mercaptopropionic acid (MPA).…”

Label-free electrochemical aptasensor for the detection of SARS-CoV-2 spike protein based on carbon cloth sputtered gold nanoparticles

“… Abrego-Martinez et al, 2022 ; Amouzadeh Tabrizi et al, 2021 ; Curti et al, 2022 ; Farrow et al, 2020 ; Jiang et al, 2021 ; Kurnia Sari et al, 2022 ; Lasserre et al, 2022 ; Singh et al, 2021 ; Tian et al, 2021 ; Zakashansky et al, 2021 .…”