Hydraulically pressed silver nanowire-cotton fibers as an active platform for filtering and surface-enhanced Raman scattering detection of bacteria from fluid

Silver and gold nanoparticles-decorated cotton fiber substrates constitute an important group of the simple, inexpensive and versatile platforms for a SERS-based detection of biomolecules. However, the fibrous cotton embedded with metal nanoparticles is yet to be explored as a filter-like substrate for isolation and detection of pathogens from fluid. In this study, we present a straightforward approach based on hydraulic pressing to make a silver nanowire-decorated cotton fibers substrate a realistic platform for effective filtering and detection of bacteria from urine. Silver nanowires were anchored on cotton fibers using an aminopropyltrimethoxysilane as a linker. The obtained silver nanowire-cotton fiber material was compressed with a hydraulic press to substantially reduce the free spaces between the individual fibers. As a proof-of-concept, the prepared substrate was employed to effectively filter Escherichia coli bacteria from phosphate-buffered saline solution and urine. The silver nanowire-cotton SERS substrate thus serves as a low-cost and active platform for an effective detection of bacteria from fluids.