Fluorometric virus detection platform using quantum dots-gold nanocomposites optimizing the linker length variation

In this study, a tunable biosensor using the localized surface plasmon resonance (LSPR), controlling thedistance betweenfluorescent CdZnSeS/ZnSeS quantum dots (QDs) and gold nanoparticles (AuNPs) hasbeen developed for the detection of virus. The distance between the AuNPs and QDs has been controlledby a linkage with a peptide chain of 18 amino acids. In the optimized condition, thefluorescent prop-erties of the QDs have been enhanced due to the surface plasmon effect of the adjacent AuNPs. Suc-cessive virus binding on the peptide chain induces steric hindrance on the LSPR behavior and thefluorescence of QDs has been quenched. After analyzing all the possible aspect of the CdZnSeS/ZnSeS QD-peptide-AuNP nanocomposites, we have detected different concentration of influenza virus in a linearrange of 10-14 to 10-9gmL-1with detection limit of 17.02 fg mL-1. On the basis of the obtained results,this proposed biosensor can be a good alternative for the detection of infectious viruses in the variousrange of sensing application.