Carbon fiber cloth-supported Au nanodendrites as a rugged surface-enhanced Raman scattering substrate and electrochemical sensing platform

Abstract

A carbon fiber cloth (CFC)-supported Au nanodendrite (CFC-AuND) prepared by simple electrodeposition of Au onto CFC has been demonstrated. The motivation of employing CFC was to fully incorporate its useful characteristics of flexibility, porosity, and conductivity in the development of substrates versatile for both surface-enhanced Raman scattering (SERS) and electrochemical measurements. To improve sample representation in SERS measurement, a wide area coverage (WAC) scheme able to cover an area of 28.3 mm(2) (illumination diameter: 6 mm) was used to compensate for the variation in Raman intensities of analytes adsorbed at different locations on the substrate. When a 1 nM 2-naphthalenethiol sample was measured using CFC-AuND, the corresponding Raman peaks were clearly observed and the substrate-to-substrate reproducibility of five separately prepared substrates was acceptable, with the relative standard deviation (RSD) of 8.5%. In addition, since the substrate was physically flexible, its SERS performance was not seriously degraded even after moderate bending. Next, the CFC-AuND substrate was used for the electrochemical detection of Hg(II) in aqueous samples by means of stripping voltammetry. The limit of detection (LOD) was 0.09 ppb and the substrate-to-substrate reproducibility was also superior, with RSDs below 3.6%. Overall, the results of the present work demonstrate the potential of CFC-AuND as a rugged, field-usable, cost-effective substrate for SERS and electrochemical measurements.