A novel dual-mode aptasensor based colorimetry and electrochemical detection of norovirus in fecal sample.

Norovirus is a leading cause of acute gastroenteritis in humans. This paper presents the development of a novel dual-mode aptasensor for detecting norovirus using colorimetry and electrochemical methods. The initial colorimetric method utilizes gold nanoparticles (AuNPs) and sodium chloride to establish a positive correlation between the concentration of norovirus in a solution and the absorbance ratio A 650 /A 520. The naked eye can detect concentrations as low as 0.1 μg/mL, corresponding to a Ct value of 33 (2.2 copies/μL, CT = 34.102–3.2185·lgX), allowing for qualitative and semi-quantitative analysis. For more accurate trace analysis, a gold electrode is modified with a thiol-modified aptamer and closed with 6-Mercapto-1-hexanol. After incubation with norovirus, the virus specifically binds to the aptamer, causing changes in its spatial structure and distance from the electrode surface. These changes can then be detected using electrochemical square wave voltammetry (SWV). Under optimal reaction conditions, the peak current from SWV exhibits a strong linear relationship with the logarithm of norovirus concentrations between 10−9 μg/mL and 10−2 μg/mL. The regression equation Y = 14.76789 + 1.03983·lgX, with an R2 value of 0.987, accurately represents this relationship. The limit of detection was determined to be 1.365 × 10−10 μg/mL. Furthermore, the aptasensor demonstrated high specificity for norovirus in fecal samples, making it a promising tool for detecting norovirus in various sample types. [Display omitted] • We propose a dual-mode aptasensor for the detection of norovirus in feces. • A colorimetric method based on nanogold and an electrochemical method based on aptamer-modified gold electrodes. • Qualitative and semi-quantitative detection by colorimetric method, quantitative detection by electrochemistry. • The assay exhibits a low detection limit and a wide linear range. • The dual-mode aptasensor provides excellent virus detection performance in both test and real samples. [ABSTRACT FROM AUTHOR]