Ultrasensitive SARS-CoV-2 diagnosis by CRISPR-based screen-printed carbon electrode

Highlights

• The ssDNA reporter randomly distributed on the electrode could be cleavaged by activated Cas12a protein as well as the ssDNA fixed upright on the surface of the electrode which could greatly shorten the time of ssDNA reporter immobilization.

• CRISPR-SPCE enabled ultra-sensitivity SARS-CoV-2 detection, with a detection limit as low as 0.27 copy/μL.

• CRISPR-screen-printed carbon electrode system is fast, high specific and low cost, thus providing a simple and faster path way for SARS-CoV-2 detection.

Abstract

Early and accurate diagnosis of SARS-CoV-2 was crucial for COVID-19 control and urgently required ultra-sensitive and rapid detection methods. CRISPR-based detection systems have great potential for rapid SARS-CoV-2 detection, but detecting ultra-low viral loads remains technically challenging. Here, we report an ultrasensitive CRISPR/Cas12a-based electrochemical detection system with an electrochemical biosensor, dubbed CRISPR-SPCE, in which the CRISPR ssDNA reporter was immobilized onto a screen-printed carbon electrode. Electrochemical signals are detected due to CRISPR cleavage, giving enhanced detection sensitivity. CRISPR-SPCE enables ultrasensitive SARS-CoV-2 detection, reaching as few as 0.27 copies μL⁻¹. Moreover, CRISPR-SPCE is also highly specific and inexpensive, providing a fast and simple SARS-CoV-2 assay.