Caracterização eletroquímica das interaçôes da lectina de sementes de Cratylia mollis (Cramoll) com glicose e eritrócitos de coelho em biossensor de MOF de [Cu3(BTC)2.(H2O)3]n.

Abstract

Biosensors are small devices known for their selectivity, high specificity and sensitivity with the respective analyte even at low concentrations. Thus, we aimed to evaluate the charge transfer and electrochemical potential of the plant popularly known as camaratu bean, a forage native to the Caatinga biome, rich in shrub legumes, from which Cramoll lectin is extracted from Cratylia mollis Mart. electrochemical biosensor using the crystalline polymer MOF- [Cu3(BTC)2.(H2O)3]n.. to immobilize and characterize the physical and chemical properties of C. mollis (Cramoll) seed lectin and its interaction with free carbohydrates (glu-cose) and carbohydrates on the surface of rabbit erythrocytes. Lectin immobilization in MOF was effective for the construction of the electrochemical system, showing itself to be sensi-tive to conformational changes, being able to detect changes in the electrochemical poten-tials of Cramoll promoted in a buffered medium (200 mM potassium phosphate buffer, pH 7.0) with different glucose concentrations, highlighting the concentrations of 10 mM (96 - 121 mV), 15 mM (110 - 126 mV) and 20 mM (107 - 142 mV) in the time of 5 to 30 min. In the cyclic voltammetry, the interaction in the potential range from -0.2 to 0.0 V stood out; with the current reaching 0.0003 A and at peak 2 in the potential range of 0.4 to 0.5 V; with the current reaching 0.0007 A. The interaction of the carbohydrate present on the surface of the rabbit erythrocyte was also monitored by the potentiometric method, detecting changes in the Cramoll-glucose potentials, even in the presence of rabbit erythrocytes. Through SEM, it was possible to observe Cramoll immobilized on the MOF surface, proving the specificity of the ligand (glucose-lectin) through the morphological changes of this protein in this process. This electrochemical model, Cramoll/MOF biosensor, is effective for evalu-ating free lectin/carbohydrate or in the erythrocyte membrane.