基于纳米MnO2二茂铁修饰丝网印刷碳电极的尿酸生物传感器研究

A Uric Acid Biosensor Based on Screen Printed Carbon Electrode Modified by MnO_2 Nano-Particles and Ferrocene

在丝网印刷碳电极上修饰纳米MnO2，并利用戊二醛和β－环糊精交联固定尿酸酶，以二茂铁作为电子媒介体，研制用于测定尿酸浓度的生物传感器。实验结果表明，纳米MnO2降低了电子媒介体二茂铁的氧化还原反应电位，且纳米MnO2与电子媒介体二茂铁在尿酸生物传感器中表现出协同增效效应。该尿酸生物传感器线性响应范围是6．0×10^-6～1．2×10^-3mol／L，检出限为3．0×10^-6mol／L。用纳米MnO2修饰酶电极．改善了电极表面条件，加快了电极反应速率，提高了尿酸传感器的灵敏度。

A novel biosensor is developed to determine the uric acid. It is prepared by utilizing glutaraldehyde cross linked β-cyelodextrin to immobilize the uricase on the surface of screen printed carbon paste electrodes which was modified by MnO2 nano-particles, and ferrocene is employed as an electron transfer mediator. The results show that MnO2 nano-particles reduce the redox potential of ferrocene, furthermore Mn（）2 nano-particles and ferrocene improve the current response of the uric acid biosensor as a synergetic effect. The uric acid biosensor＇s linear range is 6.0×10^-6 to 1.2 ×10^-3 mol/L with a detection limit of 3. 0 ×10^-6 mol/L. Compared with the electrode modified by ferrocene, the electrode modified with both ferrocene and MnO2 nano-particles sped up the electrode reaction and improves the sensitivities of the sensor by two-fold.