Determination of Methyldopa and Paracetamol in PharmaceuticalSamples by a Low Cost Genipa americana L. Polyphenol OxidaseBased Biosensor

Jenipapo fruit (Genipa americana L) is a natural source of polyphenol oxidases (PPOs)whose potential in pharmaceutical analysis is noteworthy. Henceforth, this work reports theelectrochemical study of a low-cost PPO-based biosensor produced from the crude extract ofJenipapo fruits and accounts a practical approach to employ this biosensor in the determinationof methyldopa and paracetamol in pharmaceutical samples. In order to investigate the electrochemical properties of the biosensor, theoreticaland practical approaches were employed, and both samples and the biosensor were analyzedthrough electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely:differential pulse voltammetry (DPV) and cyclic voltammetry (CV). showcased that the biosensor presented good analytical features, as well as lowdetection limits (8 μmol L-1 for methyldopa and 5 μmol L-1 for paracetamol). The relativestandard deviation was less than 5% mid-assay. The use of this biosensor is a reliable, low cost and useful alternative in thepharmaceutic determination of phenolic drugs (e.g. methyldopa and paracetamol).