A simple fluorescence analytical method was established for the quantitation of activity of β-glucosidase.The synthetic 2-O-β-glucopyranosyl ascorbic acid(AA-2βG) was used as the enzymatic substrate.β-Glucosidase catalyzed the hydrolysis reaction and released ascorbic acid

which would reduce non fluorescent resazurin to strongly fluorescent resorufin.Thus

β-glucosidase activity would be reflected by the fluorescent intensity variation of the system.Firstly

a validation assay was carried out to confirm the possibility to detect ascorbic acid taking advantage of reductive reaction.There was a linear relationship for the increased fluorescent intensity with the concentration of ascorbic acid in the range of 3-400 μmol/L with a correlation coefficient(r2) of 0.981

while β-glucosidase activity was successfully determined by measuring fluorescent intensity at 585 nm.Results showed that there also existed a good linear relationship between the increased fluorescent intensity and concentration of β-glucosidase in range of 1-30 U/L

with a correlation coefficient(r2) of 0.995 and a detection limit of 1.0 U/L.With the characteristics of simplicity

sensitivity and large detection range

the method could realize the quantitative detection on β glucosidase activity.