Determination of Methyldopa and Paracetamol in Pharmaceutical Samples by a Low Cost Genipa americana L. Polyphenol Oxidase Based Biosensor.

Rafael Souza Antunes,Eric De Souza Gil,Vernon Sydwill Sommerset,Flavio Marques Lopes,Luane Ferreira Garcia,Douglas Vieira Thomaz

doi:10.15171/apb.2019.049

Abstract

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

Highlights

Biosensing technology is a growing field in science whose potential is being gradually explored in analytical chemistry
This work reports the electrochemical study of a low-cost polyphenol oxidases (PPOs)-based biosensor produced from the crude extract of Jenipapo fruits and accounts a practical approach to employ this biosensor in the determination of methyldopa and paracetamol in pharmaceutical samples
In order to investigate the electrochemical properties of the biosensor, theoretical and practical approaches were employed, and both samples and the biosensor were analyzed through electrochemical impedance spectroscopy (EIS) and voltammetric techniques, namely: differential pulse voltammetry (DPV) and cyclic voltammetry (CV)

Summary

Introduction

Biosensing technology is a growing field in science whose potential is being gradually explored in analytical chemistry. The biological element in biosensors allows higher selectivity through enzymatic mechanisms, which in turn, increases sensitivity through the magnification of the generated chemical signal In this context, enzymes possess optimal bio-catalytic proprieties which can be used in biosensor development, and provide unmatched fast analysis, reproducibility and low-cost detection.[1,2]. Both compounds possess similar structures, their pharmacodynamic properties are distinct, as methyldopa is a α2 inhibitor, while paracetamol is a non-steroidal anti-inflammatory drug.[2,12,13] Their determination in pharmaceutical samples is already well reported, most methods are expensive, and comprise mostly of high performance liquid chromatography techniques coupled to UV-Visible spectrophotometry (HPLC-UV/Vis), which leads to the use of high amounts of solvents. This work showcases the study of the electrochemical features of a previously developed jenipapo-PPO-based biosensor (JeEE@CP)[9] and investigate its applicability to determine methyldopa and paracetamol in pharmaceutical samples

Material and Methods

Results and Discussion

Conclusion