Au Nanowire-on-Film SERRS Sensor for Ultrasensitive Hg2+ Detection

Abstract

We report an ultrasensitive and selective single nanowire-on-film (SNOF) surface-enhanced resonance Raman scattering (SERRS) sensor for Hg2+ detection based on structure-switching double stranded DNAs (dsDNAs). Binding of Hg2+ induces conformational changes of the dsDNAs and let a Raman reporter get close to the SNOF structure, thereby turning on SERRS signal. The well-defined SNOF structure provides a detection limit of 100 pm with improved accuracy in Hg2+ detection. This sensor is stable over a considerable amount of time and reusable after simple treatment. Since this SNOF sensor is composed of a single Au NW on a film, development of a multiplex sensor would be possible by employing NWs modified by multiple kinds of aptamers.