A rapid, ultrasensitive voltammetric biosensor for determining SARS-CoV-2 spike protein in real samples

• Published in: Biosensors & bioelectronics 2021-11, Vol.192, p.113497-113497, Article 113497
• Main Authors: Liv, Lokman, Çoban, Gizem, Nakiboğlu, Nuri, Kocagöz, Tanıl
• Format: Article
• Language: English
• Subjects: Biosensing Techniques; Coronavirus; COVID-19; COVID-19 - diagnosis; Electrochemical biosensor; Humans; SARS-CoV-2 spike protein; Sensitivity and Specificity; Spike Glycoprotein, Coronavirus - analysis; Viral detection; Voltammetry
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2021.113497

The ongoing coronavirus disease 2019 (COVID-19) pandemic continues to threaten public health systems all around the world. In controlling the viral outbreak, early diagnosis of COVID-19 is pivotal. This article describes a novel method of voltammetrically determining severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein with a newly designed sensor involving bovine serum albumin, SARS-CoV-2 spike antibody and a functionalised graphene oxide modified glassy carbon electrode (BSA/AB/f-GO/GCE) or screen-printed electrode (BSA/AB/f-GO/SPE). The oxidation reaction based on the antibody–antigen protein interaction was evaluated as a response to SARS-CoV-2 spike protein at -200 mV and 1430 mV with the BSA/AB/f-GO/SPE and BSA/AB/f-GO/GCE, respectively. The developed sensors, BSA/AB/f-GO/SPE and BSA/AB/f-GO/GCE, could detect 1 ag/mL of virus spike protein in synthetic, saliva and oropharyngeal swab samples in 5 min and 35 min, and both sensors demonstrated a dynamic response to the SARS-CoV-2 spike protein between 1 ag/mL and 10 fg/mL. Real-time polymerase chain reaction (RT-PCR), rapid antigen test and the proposed method were applied to saliva samples. When compared to RT-PCR, it was observed that the developed method had a 92.5% specificity and 93.3% sensitivity. Moreover, BSA/AB/f-GO/SPE sensor achieved 91.7% accuracy compared to 66.7% accuracy of rapid antigen test kit in positive samples. In view of these findings, the developed sensor provides great potential for the diagnosing of COVID-19 in real samples. [Display omitted] •The developed sensors are ultra-sensitive and have short preparation time.•The developed sensors could reduce the false-negative ratio.•No cross-reactivity with spike proteins of MERS-CoV, pneumonia and influenza A.•Achieving prospering reusability and stability rate.•Possibility of fabricating ready-to-use sensor and kit.