SiQDs/Cu2-β-CD nanoclusters: A fluorescence probe for the mutual non-interference detection of uric acid and L-cysteine under alkaline conditions

The fluorescence probes based on quantum dots (QDs) have been widely used in the detection of uric acid (UA), but other biomolecules such as biothiols, ascorbic acid and dopamine have interference with the detection result due to their similar chemical properties. Herein, SiQDs/Cu-2-beta-CD nanoclusters were prepared via coordination -driven self-assembly between Cu-2-beta-CD and -NH2 on the surface of SiQDs, and UA could attenuate the fluorescence of the nanoclusters under strong alkali conditions, while L-cysteine (L-Cys) had no effect. Under the optimum conditions, the decreased fluorescence intensity is linearly proportional to the concentration of UA in the range of 0.025-0.15 mM with a detection limit of 4.9*10(-3) mM. Furthermore, under neutral or weak base conditions, L-Cys could improve the fluorescence of the nanocluster, but UA had no effect, which could also be used to detect L-Cys. This work provides a sensitive, selective and convenient fluorescence method for UA and L- Cys detection in the present of another interfering biomolecule.

Automated summary

This study presents a sensitive and selective fluorescence method for the detection of UA and L-Cys using SiQDs/Cu-2-beta-CD nanoclusters. Under strong alkali conditions, UA attenuates the fluorescence of the nanoclusters, while L-Cys has no effect, providing a selective detection method. Under neutral or weak base conditions, L-Cys enhances the fluorescence of the nanoclusters, while UA has no effect, which can also be used for the detection of L-Cys.