Electrochemical sensing of Staphylococcus aureus based on conductive anti-fouling interface

A system for the rapid and ultra-sensitive detection of Staphylococcus aureus (S. aureus), a prevalent foodborne pathogen is introduced. Limitations of typical electrochemical sensing, often subjected to interference from non-specific protein adsorption are addressed. A dual-aptamer-based sandwich immunobiosensor is shown for its benefits regarding specificity and anti-fouling capacity, endowed by a sulfonated polyaniline layer combined with signal amplification via highly conductive gold nanoparticles. EIS spectra (Nyquist plots) were recorded at pH 7.4 PBS containing 5 mM Fe(CN)(6)(3-)/Fe(CN)(6)(4-), in order to verify the possibility of the electrochemical sensing for detection of S. aureus. Results demonstrated that the constructed immunobiosensor presents an extended detection range (1 x 10(1) to 1 x 10(5) CFU/mL) and detection limit as low as 2 CFU/mL. The resistance values of the immunobiosensor developed maintain at a stable value during 2 weeks. Besides, the specificity of the system is highlighted by testing raw milk, and the results of which demonstrate the excellent prospects of the system for monitoring foodborne pathogens.

Automated summary

This article introduces a system for the rapid and ultra-sensitive detection of the prevalent foodborne pathogen Staphylococcus aureus. By utilizing a dual-aptamer-based sandwich immunobiosensor, the system demonstrates specificity and anti-fouling capacity, with signal amplification through highly conductive gold nanoparticles. Experimental results show that the immunobiosensor has an extended detection range and low detection limit, while maintaining stability for two weeks.