Versatile chemical sensors using oligosaccharides on cleanable PDMS/graphene hybrids for monitoring environmentally hazardous substances

A versatile chemical sensor possessing a nontoxic sensing medium was produced for the detection of chemical environmental hazards. Poly(dimethylsiloxane) (PDMS)/graphene (GR) hybrids were employed as sensor substrates owing to their high electrical conductivity. The PDMS/GR hybrid substrates exhibited a significant change in electrical threshold above 1.2 wt% GR loading. Oligosaccharides, such as beta-cyclodextrin (beta-CD), were introduced and used as sensing media for the detection of potentially hazardous molecules. The successful introduction of the sensing medium was confirmed by a variety of instrumental analyses. The sensor signal generated by addition of target analyte originated from charge transport associated with the formation of beta-CD-analyte inclusion compounds, which were monitored by ultraviolet (UV) spectroscopy. The performance of this sensor system was examined using various concentrations of a model analyte, methyl paraben (MePRB), and yielded a limit of detection of approximately 10 nM.