Self-assembled multilayers of water-soluble modified-chitosan and glucose oxidase for detection of glucose in milk samples

GULOTTA, FLORENCIA A., ; MONTENEGRO, MARIANA, DIAZ VERGARA, LADISLAO, ; FERREYRA NANCY F.*; PAZ ZANINI VERÓNICA

Congreso; SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY CONFERENCE; 2022

SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY

Multilayer films made of glucose-functionalized chitosan (G-Chit) and glucose oxidase (GOx) were built by layer-by-layer self-assembly technique onto carbon paste electrodes (CPE). The obtained bioelectrodes were characterized by cyclic voltammetry and chronoamperometry. Results indicated that catalytic response increases both with the number of bilayers G-Chit/GOx and the enzyme concentration obtaining the best responses for 3 bilayers and 2 mg ml-1, respectively. The effect of pH on the bioelectrode response was also investigated, we found that the optimal working value is 7.0. Under optimized experimental conditions, the biosensor exhibits a sensitivity of (0.81 ± 0.03) µA mM-1 in a glucose concentration range 0.18 to 1.75 mM. The analytical response of the biosensor was tested in milk samples with negligible matrix effects. Results show that G-Chti appears promising for the immobilization of enzymes.