Preparation of a disposable and low-cost electrochemical sensor for propham detection based on over-oxidized poly(thiophene) modified pencil graphite electrode

Abstract

In this study, an electrochemical sensor was developed for the determination of propham (PRO) in potato, human urine and river water samples based on the over-oxidized poly(thiophene) modified pencil graphite [PG/p(Thp)-Ox] electrode. Adsorptive stripping differential pulse voltammetry was used as a voltammetric method. The PG/p(Thp)-Ox electrode increased the oxidation peak current of PRO 30 times according to bare PG. Electrochemical polymerization and over-oxidation conditions were deeply optimized to increase the sensitivity of PG/p(Thp)-Ox. Characterization of PG/p(Thp)-Ox was performed via scanning electron microscopy and cyclic voltammetry analysis. Oxidation peak current value of PRO linearly increased with the concentration of PRO in the ranges of 0.005-1.0 mu M and 2.0-15.0 mu M. A very low limit of detection value (1.0 nM) was obtained. Intra-day and inter-day reproducibility of the PG/p(Thp)-Ox were determined as 2.96% (N: 10) and 4.77% (10 days), respectively. Satisfactory recovery values (98.07-104.4%) were observed with PG/p(Thp)-Ox electrode during the analysis of PRO in PRO-spiked potato, urine and river water samples. The results show that the PG/p(Thp)-Ox could be used safely in the determination of PRO.