Selective detection of picric acid using functionalized reduced graphene oxide sensor device

A reduced graphene oxide sensor device was fabricated through self-assembling graphene oxide onto an interdigitated gold microelectrode followed by electrochemically reducing. After modification with 1-pyrenebutyl-amino-β-cyclodextrin, the sensor exhibits high sensitivity and selectivity to picric acid. The sensor response (ΔI) increases linearly with concentration in the range of 5 μM to 215 μM. The sensitivity and detection limit of this method were estimated to be 0.00613 μA μM−1 and 0.54 μM, respectively. The improved performance can be attributed to the unique structure of β-cyclodextrin (hydrophobic internal cavity and hydrophilic external surface), which endows its great tendency to integrate with hydrophobic –NO2 groups of picric acid. Picric acid extracted from real water by ether can be determined effectively with this method, which demonstrates that the present method is sensitive and suitable for the determination of picric acid in drinking water sources.