Manipulação de superfície de sensor eletroquímico para detecção de aminas biogênicas e neurotransmissores utilizando nanopartículas, nanotubos de carbono e nanocompósitos

Abstract

This work describes the development of chemically modified electrodes, built from nanostructured materials for the detection of biogenic amines and neurotransmitters. Three types of electrodes were developed in order to assess which one has the best sensitivity and specificity for the detection of biogenic amines (cadaverine, spermidine, histamine, histidine and putrescine). The first sensor was prepared from the modification of a glassy carbon electrode and copper nanocomposites, proving to be sensitive for the detection of dopamine. The second proposed electrode was constructed from the surface modification of a glassy carbon electrode and HAuCl4, showing to be sensitive to dopamine, with specific signal and increasing cathodic peak between 0.4 and 0.6 V, presenting an R= 0 .96 and sensitive for spermidine, with specific signal and cathodic peak increasing between 0.6 and 0.8 V. The third proposed electrode was constructed from the modification of the surface of a glassy carbon electrode with Cu/doped ZnO nanocomposites. CuO The modified NTC+ZnO:4Cu electrode, presenting linearity from 50 to 90 µmol L-1 and LD of 9.31 µmol L-1. The modified NTC+ZnO:12Cu electrode, presenting linearity from 30 to 100 µmol L-1 and LD of 12.58 µmol L-1. The modified NTC+CuO electrode, presenting linearity from 20 to 100 µmol L-1 and LD of 14.08 µmol L-1. The modified NTC+ZnO electrode, presenting linearity from 20 to 90 µmol L-1 and LD of 7.58 µmol L-1. The electrode was modified only with NTC, showing linearity from 20 to 90 µmol L-1 and LD of 13.50 µmol L-1. With increasing concentration of CuO nanocomposites, a decrease in electrode sensitivity was observed. When compared to all, the NTC+ZnO:4Cu electrode proved to be efficient for the detection of dopamine, with analytical curves showing good linearity and low limits of detection and quantification.