Sensitive cholesterol determination by β-cyclodextrin recognition based on fluorescence enhancement of gold nanoclusters

Abstract

As one of the most important biomarkers for cardiovascular disease and high blood pressure, cholesterol quantification is of great importance for clinical diagnosis and health management. In this study, mercapto-β-cyclodextrin capped gold nanoclusters have been used as fluorescent probes for succinct and sensitive determination of cholesterol. Using mercapto-β-cyclodextrin as a reducing and capping agent, gold nanoclusters with bluish-green fluorescence were synthesized by the one-pot hydrothermal method. The cyclodextrin cavities of the capping layer on gold nanoclusters act as selective units for cholesterol recognition, and the gold cores serve as signal reporting units. The host–guest interaction between cholesterol and cyclodextrin directly enhances the fluorescence of gold nanoclusters without the involvement of additional dyes or quenchers. Under the optimal conditions, the probe responds linearly to cholesterol in the concentration range of 10.0 ∼ 100.0 μmol·L-1 with the detection limit of 5.77 ± 0.18 μmol·L-1 (3σ, n = 3). Common coexisting components in the serum did not interfere with the detection of cholesterol. Satisfactory results were obtained for the determination of cholesterol in real serum samples by the proposed method.