GQD as a probe and Graphene Oxide (GO)-Au/Ag nanocarriers for faster and more sensitive E. coli and S. aureus detection

Graphene quantum dots (GQDs) are a distinct class of quantum dots that demonstrate notable electro-catalytic capabilities. The primary objective of this study was to investigate the properties of graphene quantum dots (GQDs) and compare them to semiconductor quantum dots (CdSe QDs) in order to evaluate GQD’s potential as highly sensitive agents for the detection of bacteria. Escherichia coli and Staphylococcus aureus are recognized as the predominant pathogens responsible for causing diseases worldwide. Failure to immediately diagnose and treat these pathogens can lead to severe and sometimes devastating outcomes. In this study, the sensing platform utilises Screen-Printed Carbon Electrodes (SPCE) that have been modified with Graphene Oxide/gold nanoparticles (GO-AuNP) and Graphene Oxide/silver composite nanoparticles (GO-AgNP). Furthermore, we utilised electrochemical (EC) probes in conjunction with co-reactants, namely nitrogen-doped graphene quantum dots (N-GQDs) and cadmium selenide quantum dots (CdSe QDs). The incorporation of graphene oxide-gold nanoparticle (GO-AuNP) and graphene oxide-silver nanoparticle (GO-AgNP) nanocomposites has been observed to enhance the stability and amplification capabilities of the biosensor. By employing this methodology, it is possible to rapidly detect pathogens in real samples even at concentrations as low as 1 CFU/mL.