在pH 9.0的PBS介质中葡萄糖与亚甲基蓝反应,使亚甲蓝荧光猝灭。若换用β-环糊精/亚甲基蓝荧光探针,则体系的荧光猝灭强度大大提高。葡萄糖的质量浓度在0.02~26 mg·L-1之间与其荧光强度呈线性关系,检出限(3S/N)为0.002 mg·L-1。据此,建立了以β-环糊精/亚甲基蓝为荧光探针直接测定葡萄糖的荧光分析方法。该体系最大激发波长为660 nm,最大发射波长为678 nm。加标回收率在97.4%~101%之间,测定值的相对标准偏差(n=5)在均小于2.5%。

In a PBS medium of pH 9.0, fluorescence of methylene blue was quenched by reaction with glucose and intensity of fluorescence quenching of methylene blue was enhanced obviously by using β-cyclodextrin/Methylene blue as fluorescent probe. Linear relationship between values of intensity of fluorescence quenching and mass concentration of glucose was kept in the range of 0.02-26 mg·L-1, with detection limit (3S/N) of 0.002 mg·L-1. Based on these facts, a fluorospectrophotometric method for the determination of glucose with β-cyclodextrin/methylene blue as fluorescent probe was proposed. Its maximum excitation wavelength was 660 nm, and the maximum emission wavelength was 678 nm. Values of recovery found by standard addition method were in the range of 97.4%-101%, and values of RSD′s (n=5) less than 2.5%.