An all-in-one assay for bacteria-related detections through gold nanoparticles-amplified electrical conductivity.

An all-in-one assay based on the electrical conductivity (EC) has been developed that enables the viability test and the specific detection of pathogenic bacteria, including the differentiation of (1) live/dead bacteria, (2) drug-sensitive/resistant bacteria, (3) Gram-positive/negative bacteria, and (4) specific detection of A. baumannii. Key to this assay is the modification of gold nanoparticles on the surface of bacteria that can amplify the EC signal for enhanced sensitivity and rapid detection. The amplification effect of gold nanoparticles significantly reduces the time and enhances the sensitivity for bacteria detection. This EC-based assay outcompetes traditional colorimetric and fluorescent methods owing to its rapid response, convenient operation, and low cost, which holds great promise for biosensing.