The potential use of hydrazine as an alternative to peroxidase in a biosensor: comparison between hydrazine and HRP-based glucose sensors.
The potential use of hydrazine sulfate was examined for the catalytic reduction of enzymatically generated H2O2 in a biosensor system. The performance of the hydrazine-based sensor was compared with an HRP-based glucose sensor as a model of a biosensor. Hydrazine and HRP were covalently immobilized onto a conducting polymer layer with glucose oxidase. The direct electron transfer reactions of the immobilized hydrazine and HRP onto the poly-5,2':5,2''-terthiophene-3'-carboxylic acid (poly-TTCA) layer were investigated by using cyclic voltammetric method and the electron transfer rate constants were determined. The glucose oxidase- and hydrazine-immobilized sensor efficiently reduced the enzymatically generated H2O2 at -0.15 V versus Ag/AgCl. The surface of this GOx/hydrazine/poly-TTCA-based glucose sensor was characterized by QCM, SEM, and ESCA. Glucose-sensing properties were studied using cyclic voltammetric and chronoamperometric techniques. Various experimental parameters were optimized according to the amount of hydrazine, pH, the temperature, and the applied potential. A linear calibration plot was obtained in the concentration range between 0.1 and 15.0 mM, and the detection limit was determined to be 40.0+/-7.0 microM. Interferences from other biological compounds were studied. The long-term stability of the GOx/hydrazine sensor was better than that of the one based on a GOx/HRP biosensor. The proposed glucose sensor was successfully applied to human whole blood and urine samples for the detection of glucose.
Rahman
Md Aminur
MA
Department of Chemistry and Center for Innovative Bio-Physio Sensor Technology, Pusan National University, Busan 609-735, South Korea.
Won
Mi-Sook
MS
Shim
Yoon-Bo
YB
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000032:analysis / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005947:Glucose / Q000032:analysis* / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000032:analysis / Q000737:chemistry*; D006834:Hydrazines / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties
D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D006834:Hydrazines; C029424:hydrazine; D006735:Horseradish Peroxidase; D005947:Glucose