Aerosol Jet Printing Enabled Dual-Function Electrochemical and Colorimetric Biosensor for SARS-CoV-2 Detection

Abstract

An aerosol jet printing enabled dual-function biosensor for the sensitive detection of pathogens using SARS-CoV-2 RNA as an example has been developed. A CRISPR-Cas13: guide-RNA complex is activated in the presence of a target RNA, leading to the collateral trans-cleavage of ssRNA probes that contain a horseradish peroxidase (HRP) tag. This, in turn, catalyzes the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by HRP, resulting in a color change and electrochemical signal change. The colorimetric and electrochemical sensing protocol does not require complicated target amplification and probe immobilization and exhibits a detection sensitivity in the femtomolar range. Additionally, our biosensor demonstrates a wide dynamic range of 5 orders of magnitude. This low-cost aerosol inkjet printing technique allows for an amplification-free and integrated dual-function biosensor platform, which operates at physiological temperature and is designed for simple, rapid, and accurate point-of-care (POC) diagnostics in either low-resource settings or hospitals.

Heavy Metal-Induced Assembly of DNA Network Biosensor from Double-Loop Hairpin Probes for Ultrasensitive Detection of UO22+ in Water and Soil Samples

“…Signal amplification is an efficient way to improve the detection sensitivity in biosensor design . The commonly used protein enzyme-mediated signal amplification strategies have received great attention in biosensor fabrication using horseradish peroxidase, phosphatase, exonuclease, and polymerase as catalysts. However, the enzyme is costly and susceptible to environmental factors, such as temperature and pH .…”