Fullerene and platinum composite-based electrochemical sensor for the selective determination of catechol and hydroquinone

For the selective determination of two isomers of phenolic compounds, namely, catechol (CC) and hydroquinone (HQ), a new electrochemical sensor that is based on platinum nanoparticles (Pt NPs) and fullerene (C-60) composite was constructed by modifying Pt/C-60 composite on the surface of a pyrolytic graphite electrode (PGE). The as prepared Pt/C-60/PGE exhibited excellent distinguishing capacity for the oxidation of CC and HQ and showed a strong oxidation current and enhanced catalytic activity. The results of differential pulse voltammetry (DPV) experiments demonstrate that the peak-to-peak potential difference in the oxidation of CC and HQ can be separated from 76.9 mV for Pt NPs modified PGE to 101 mV for Pt/C-60/PGE. Pt/C-60/PGE was used to selectively determine CC and HQ in the mixed solution under the optimized conditions, and it performed well over wide linear concentration ranges from 50.0 to 1500.0 mu M for CC and 50.0 to 1100.0 mu M for HQ. The limits of detection (LODs) for CC and HQ were evaluated to be 2.97 mu M and 2.19 mu M, respectively. Moreover, Pt/C-60/PGE was successfully applied to detect CC and HQ in real water samples with satisfactory recoveries of 96.2-103.8% for CC and 95.7-104.4% for HQ. Therefore, based on the excellent determination performance, good stability, and high selectivity of the sensor, the Pt/C-60 composite possesses special advantages for the fabrication of electrochemical sensors for determining CC and HQ.