Phase Selective Alternating Current Voltammetric Signalling Protocol: Application in Dendritic Co-polymer Sensor for Anthracene

A sensitive anthracene (AN) sensor was developed with a gold electrode modified with a dendritic star-copolymer film by in situ electrochemical co-polymerization of generation 3 propylenethiophenoimine and 3-hexylthiophene. The sensor's {Au/G3PPT-co-P3HT: i. e. gold-generation 3 poly(propylenethiophenoimine)-co-poly(3-hexylthiophene)} analytical response for anthracene was obtained by phase selective alternating current voltammetric (PSACV) signal transduction. An in-phase angle of 0° yielded the most sensitive stripping signal and produced the best discrimination between the Faradaic and capacitive currents. The PSACV sensor exhibited a linear range (LR) of 3.48–56.4 nmol/L AN and a limit of detection (LOD) of 2.62 nmol/L AN. The LOD is comparable to the value of 4.4 nmol/L AN reported for glassy carbon electrode modified with graphenated polyaniline sensor. The low LOD value suggests that the AN sensor has promise for monitoring compliance to World Health Organisation (WHO) approved limit for polyaromatic hydrocarbons (PAHs) in wastewater (3.93 nmol/L). The Au/G3PPT-co-P3HT sensor is not as sensitive as gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) and reversed-phase high performance liquid chromatography (RP-HPLC) methods. However, the advantage of the PSACV signalling protocol is that real sample test results indicate that the sensor can be used for the determination of AN in oil-polluted wastewater.