A ratiometric fluorescence sensor for determination of choline based on gold nanoclusters and enzymatic reaction

Choline (ChO) is a biomarker of many diseases. Its accurate and sensitive detection is of great significance for the diseases diagnosis. Gold nanoclusters with bovine serum albumin as template (BSA-AuNCs) were synthesized by microwave-assisted method. A ratiometric fluorescence sensor was constructed based on BSA-AuNCs and 2,3-diaminophenazine, which was the oxidation product of o-phenylenediamine. Combined with cascade enzymatic reaction, it was used for the detection of choline. In the detection system, choline oxidase improved the selectivity of detection, and the peroxidase-like activity of molybdenum disulfide nanosheets shortened the detection time. The linear ranges of choline detection by ratiometric fluorescence sensor were 0.5-20 mu M and 20-100 mu M. The detection limit was 0.27 mu M. The ratiometric fluorescence sensor was easy to operate and had good selectivity. Compared with single signal sensor, it can effectively reduce the error interference such as environmental change, and the detection result was more accurate.

Automated summary

A ratiometric fluorescence sensor was constructed based on BSA-AuNCs and 2,3-diaminophenazine for the accurate and sensitive detection of choline. The sensor utilized choline oxidase for improved selectivity and molybdenum disulfide nanosheets with peroxidase-like activity for shortened detection time. The sensor exhibited a linear range of 0.5-20 μM and 20-100 μM for choline detection, with a detection limit of 0.27 μM. It provided a more accurate detection result compared to single signal sensors by reducing error interference.