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Updated: Aug 3, 2026
Use of the Protease Fluorescent Detection Kit to Determine Protease Activity
Published on: August 4, 2009
Ratiometric fluorescent detection of protease activity in foods based on microwave-assisted synthesized
Haoxing You1, Jun Xiong1, Ruichen Gao1
1Lab of Applied Biocatalysis, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, No. 381 Wushan Road, Guangzhou 510640, Guangdong, China.
Abstract:
Developing a versatile probe for activity detection of protease is of significant importance due to its crucial roles in food processing, disease diagnosis, and pharmaceuticals. However, the sensitivity of probe towards interfering agents especially in complex samples hindered its development. Here, casein-directed gold nanoclusters (casein-AuNCs) were fabricated in a household microwave oven in 30 s, which displayed strong red emission with a large Stokes shift of 310 nm and high storage stability. Conjugation of fluorescein isothiocyanate (FITC) with casein-AuNCs enabled the ratiometric fluorescent detection of protease activity. Mechanistic investigation confirmed that upon protease hydrolysis, aggregation of AuNCs occurred, leading to fluorescence decay. This sensor exhibited good linearity and sensitivity for protease activity detection over a wide pH range, with detection limits of 0.29 U/mL and good anti-interference performance in real sample analysis.
