Vertical gold nanowires-based surface-enhanced Raman scattering for direct detection of ocular bacteria

Abstract

Facile, rapid, and sensitive detection of pathogens is very crucial to control pathogen infection at its early stage. In this work, an ultrasensitive surface-enhanced Raman scattering (SERS) determination of ocular bacterial pathogens on vertically aligned gold nanowires (v-AuNWs) was proposed. The v-AuNWs substrate for the optimal SERS enhancement was obtained via optimizations of three experimental conditions, including the size and the spacing distances of seed nanoparticles, and the length of v-AuNWs, which was capable of non-labeled molecular detection and quantification, as well as bacterial analysis in clinical fluids. Furthermore, a high bacterial enrichment efficiency of up to 67% has been achieved by using a herringbone microchannel on the v-AuNWs substrate. As a result, the most common ocular bacterial pathogens, S. aureus, E. coli, P. aeruginosa, and S. epidermidis, have been discriminated on the v-AuNWs SERS platform facilitated by the partial least-squares discriminant analysis (PLS-DA) with an accuracy of 97.5%. This fast, non-labeled, and accurate bacterial sensing platform offers new possibilities for screening and control of microbial infection, especially in remote areas.