Trace detection of thiols with Fourier transforms cyclic voltammetry technique in flowing solutions

Electrochemical experiments have an increasing demand for determining the concentration of biological and environmental samples as simple, inexpensive, and rapid analytical methods. Most developments in electroanalytical chemistry in recent years have originated from advances in sensor design, chemical modification, and functionalization of electrodes for enhanced sensitivity and selectivity of electroanalysis. In this work, a novel method for the fast monitoring of a thiol compound in flow injection systems has been developed. The fast Fourier transform continuous cyclic voltammetry at carbon paste electrode in flowing solution system was used for the determination of a thiol compound. The suggested technique demonstrated some advantages over other reported methods. Picomolar detection limit that is fast enough for the determination of any thiol compound was achieved. The linearization equation was current = 24.601x + 3.7068, with the correlation coefficients of 0.9812. The obtained detection limit was calculated to be 14.80 × 10−14 mol thiocholine (thiol compound sample). This system offers the necessary accuracy, sensitivity, and selectivity to assay a thiol compound in various sensors.