Rapid Detection of Staphylococcus aureus from Gym Environments for Health Risk Monitoring Using Printed Nanochains-Based Biosensors

Gyms are indoor environments in which many people perform physical exercise and could potentially increase the risks of bacterial contamination and dissemination. <i>Staphylococcus aureus</i> (<i>S. aureus</i>) is one of the most prevalent bacteria in community-acquired infections; thus, the rapid detection and continuous monitoring of <i>S. aureus</i> are crucial for evaluating the hygienic status of gym environments. This work describes the fabrication of a nanochain-based biosensor for <i>S. aureus</i> detection using carboxyl-modified polystyrene (PS) nanoparticles functionalized with a specific antibody. When target bacteria bind to the nanochains, they yield distinct color changes which support the directly visualizable analysis of optical images, recorded using optical microscopy or even a smart mobile phone. In addition to high portability, this biosensor is also capable of the quantification and continuous monitoring of the bacterial load in a gym environment over a broad linear range (10⁰ CFU/mL~10⁵ CFU/mL), with a detection limit of 1 CFU/mL. In summary, this study validated the applicability of the biosensors for the rapid detection and real-time monitoring of gym environmental pathogens.