Otimização e Caracterização da Montagem de um Biossensor para Detecção de Salmonella Typhimurium

In order to achieve fast and specific biosensors, optimizations studies are performed to find ideal conditions for the development of them. In this paper, optimization studies were carried out for pre-treatment assays, biomolecules immobilization (primary antibody and protein A concentrations) and analytic response (hydroquinone and hydrogen peroxide concentrations), by applying the technique of cyclic voltammetry. The analytical response of the immunosensor was obtained using a secondary antibody labeled with enzyme peroxidase, and the signal was evaluated by applying the technique of chronoamperometry. The immunosensor was characterized by ATR-FTIR and electrochemical measurements by cyclic voltammetry. The optimization studies for protein A and primary antibody concentrations presented a higher analytical signal for 7.5 and 75.0 mg mL-1 , respectively. The hydroquinone and H2O2 concentrations selected were of 3 mM and 300 mM, respectively. The immunosensor showed a linear response (R2 = 0.96) for Salmonella Thyphimurium with a detection limit of 10 CFU mL-1 and detection time of 125 min for the final response.