Aproveitamento e aplicação de serinoproteases de Genyatremus luteus em biossensor para detecção de metais em amostras ambientais

Abstract

Heavy are widespread environmental pollutants worldwide, and because of their hazardous nature, it is necessary to develop rapid and sensitive detection methods. In this work, a biosensor was constructed by immobilization of a trypsin rich fraction (FRT) extracted from the pyloric cecum of the Genyatremus luteus on the working electrode of a silkscreen sensor. Assays were performed with the free enzyme in solution and immobilized in a sensor, in order to verify its activity. After optimization of the operating conditions, such as substrate concentration, medium pH, type of enzymatic immobilization, among others, the biosensor was characterized by differential pulse voltammetry and chronoamperometry, and the following merit figures were then determined: linearity, precision , sensitivity and accuracy. n the kinetic study, an increase in trypsin activity with substrate concentration was observed until stabilization at a mean concentration of 0.178 mmol.L-1. The results indicated good performance for the FRT of G. luteus with respect to linearity (for metals), to repeatability (mean CV of 15,61% ± 2,0% between measurements with different biosensors) and sensitivity (with detection limits of 0.029, 0.025 and 17.6 μ.L-1, for the Hg, Fe and Zn, respectively). The results showed that FRT extracted from G. luteus can effectively be used to obtain highly sensitive and reproducible biosensors for the detection / quantification of metals in the aquatic environment.