Molecular Sensing By Sers Using Entangled Nanofibers

Abstract A kissing nanofiber junction, a junction created by crossing nanofibers that are plasmonically active, is a novel and powerful concept for inducing strong and broadband electric field enhancement. If combined with surface-enhanced Raman spectroscopy (SERS), junctions out of kissing nanofibers could lead to ultrahigh sensing mechanism. Realization of myriads of the kissing nanofiber junctions, however, faces a hurdle in viable manufacturing if using a nanolithography-based, complex procedure. Having a flexible one-dimensional nature, nanofibers may help overcome this hurdle and embody the idea of the kissing nanofiber junctions for chemical sensing. Here, we introduce a concentric nanoarchitecture on carbon nanofibers, facile lithography-free nanofabrication based on randomly entangled nanofibers, and clear demonstration of the field enhancement in a way of ultrasensitive (femtomolar-level) chemical detection. As a chemical sensor, for instance, SERS can generally offer a sensitive and selective platform, though leaving multiplexibility as a remaining issue. The kissing-nanofiber-junction-based SERS sensor can address this multiplexibility issue possibly in the perspective of competitive adsorption of multiple species. We provide the readers with the state of the art of the nanofiber-based SERS technique along with its challenges and opportunities toward powerful chem-bio sensing.