A paper-based photoelectrochemical aptsensor using near-infrared light-responsive AgBiS2 nanoflowers as probes for the detection of Staphylococcus aureus in pork

Staphylococcus aureus is a gram-positive bacterium that can easily cause outbreaks of food-borne diseases. In this work, a signal-enhanced three-dimensional paper-based photoelectrochemical (PEC) aptsensor for the rapid and sensitive determination of S. aureus was developed. Specifically, gold nanoparticles (AuNPs) were electrodeposited on a paper-based working electrode to provide binding sites for a sulfhydryl-functionalized aptamer. Subsequently, S. aureus was captured with high specificity by a carboxyl-functionalized aptamer modified with amino-functionalized AgBiS2 nanoflowers (NH2-AgBiS2 NFs), which functionalized as PEC probes that generated strong photocurrent under irradiation with 980-nm light. By exploiting the aptamer-target-aptamer PEC sensing platform, the rapid and ultrasensitive detection of S. aureus was achieved. The sensor had a wide linear range of 20 to 2 x 10(7) CFU/mL and low limit of detection of 4 CFU/mL. Further, the applicability of the as prepared aptsensor was successfully certified for the analysis of pork samples artificially contaminated with S. aureus.

Automated summary

In this study, a novel paper-based photoelectrochemical sensor was developed for rapid and sensitive detection of Staphylococcus aureus. By utilizing specific modifications, the capture of S. aureus with high specificity was achieved, and signal enhancement was achieved using nanoflower probes. The sensor demonstrated rapid and ultrasensitive detection capabilities.