壳聚糖固定化葡萄糖氧化酶生物传感器测定葡萄糖的含量

应用壳聚糖将葡萄糖氧化酶固定于鸡蛋膜上,结合氧电极制得葡萄糖传感器.实验表明,壳聚糖比戊二醛能更好地固定葡萄糖氧化酶,最佳条件为壳聚糖浓度0.3%、固定化酶量0.8 mg、 pH 7.0、缓冲溶液浓度300 mmol/L和温度25 ℃.本葡萄糖传感器的线性范围为0.016～1.10 mmol/L;检出限为8.0 μmol/L(S/N=3), 响应时间<60 s,有很好的稳定性,寿命>3个月.同一个传感器重复使用以及同方法制作的不同传感器之间都有很好的重现性,RSD分别为2.5%(n=10)和4.7%(n=4).实际样品中可能存在的烟酰胺、 VB6、 VB12、 VE、Ca2+、 Mg2+、 K+和Zn2+等对葡萄糖的测定不产生干扰.本传感器已成功地应用于市售饮料中葡萄糖含量的测定.

Determination of Glucose with Biosensor by Immobilization of Glucose Oxidase with Chitosan

A glucose biosensor was fabricated from a glucose oxidasE-immobilized by chitosan and oxygen electrode. The effects of concentration of chitosan(0.3%), enzyme loading(0.8 mg), pH 7.0, phosphate buffer concentration(300 mmol/L), and temperature 25 ℃ for the response of the biosensor were investigated. The glucose biosensor has a linear response range of 0.016-1.10 mmol/L with a detection limit of 8.0 μmol/L(S/N=3). The response time was less than 60 s. The biosensor showed extremely good stability with a shelf-life of at least 3 months. The biosensor exhibited good repeatable response to a 0.25 mmol/L glucose olution with a relative standard deviation of 2.5%(n=10). The precision of fabrication of the biosensors using four different membranes was good with a RSD of 4.7%. Some common potential components in sample such as niacinamide, vitamin B6, vitamin B12, vitamin E, Ca2+, Mg2+, K+ and Zn2+ showed no interferences on the response of the glucose biosensor. The biosensor was successfully applied to determine the glucose in commercial beverage samples.