基于中空氧化镍纳米微球和离子液体复合膜固定血红蛋白的NaNO2生物传感器

采用微波水热法合成了一种中空氧化镍纳米微球(NiO), 然后将其与1-丁基-3-甲基-咪唑四氟硼酸盐(BMIMBF4)的复合膜用于血红蛋白(Hb)在碳糊电极上的固定, 制备了NaNO2生物传感器. 通过扫描电子显微镜、 傅里叶变换红外光谱及紫外-可见光谱等分析表明, Hb已固定于NiO和BMIMBF4的复合膜中并能保持其生物活性; 进一步通过电化学阻抗法研究了修饰电极中混合物各组分的作用. 结果表明, 在NiO和BMIMBF4的复合膜中, Hb能实现有效的直接电子转移, 且修饰后的电极对NaNO2有良好响应, 响应时间小于5 s, 检出限为4.57 μmol/L(S/N=3), 灵敏度为46.2 μA·L·mmol-1, 线性范围为10~170 μmol/L, 表观米氏常数KM为2.4 mmol/L, 该方法的重现性和电极的稳定性良好.

NaNO2 Biosensor Based on Hollow Nano-nickel Oxide Microsphere and Ionic Liquid Composite Film Immobilizing Hemoglobin

Hollow nano-nickel oxide microsphere (NiO) was fabricated by microwave hydrothermal process and characterized by SEM. The prepared NiO was used to immobilize hemoglobin(Hb) on the surface of the carbon paste electrode with 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4). The structure of Hb in the composite film was still maintained native-like demonstrated by FTIR spectra and UV-visible spectra. Moreover, the functions of different components in the modified electrode were studied by electrochemical impedance spectroscopy. A pair of stable and quasi-reversible redox peaks was observed in phosphate buffer solution which indicating that heme-proteins could achieve its direct electron transfer effectively. The modified electrode displayed an excellent and rapid electrocatalytic response to the oxidation of NaNO2. The proposed biosensor exhibited a good linear response to the concentration of NaNO2 in the range of 10-170 μmol/L, with a detection limit of 4.57 μmol/L(S/N=3). The apparent Michaelis-Menten constant was estimated to be 2.4 mmol/L. Furthermore, the biosensor possesses satisfactory stability and good reproducibility.