Construction of "Off-On" Bioluminescence Sensor Based on Phosphorescence Resonance Energy Transfer for Selective Detection of Cholesterol

Cholesterol is one of important indicators in the clinical biochemical examination. Developing a new method for the sensitive and accurate detection of cholesterol level in biological samples is of great significance to human health. Conventional fluorescent probes suffer from the interference of strong biotissue autofluorescence, which severely limits their applications in biology detection. In this study, an "Off-On" bioluminescent sensor was designed for detection of cholesterol based on manganese dioxide (Mn02) coated with long afterglow nanoparticles. According to resonance energy transfer, the afterglow of ZnGa204: Cr3+,Y3+ could be obviously quenched by Mn02 nanosheets. When cholesterol oxidase and cholesterol coexisted, cholesterol was catalyzed to produce hydrogen peroxide (H202), which reduced Mn02 in acid conditions, thus facilitating the decomposition of Mn02 nanosheets. Therefore, the afterglow of ZnGa204: Cr3+,Y3+ core was recovered. Under optimal conditions, the intensity of ZnGa204 : Cr3+,Y3+ afterglow recovery showed a good linear relationship with cholesterol concentration in the range of 8-200 & mu;moUL and the limit of detection was 1.7 & mu;moUL (SIN=3). This method was successfully applied to detection of cholesterol in human serum, plasma and urine after being verified by standard cholesterol. The recoveries were in the range of 87.7%-109.5%. The experimental results showed that the "Off-On" luminescence sensor based on phosphorescent resonance energy transfer of long afterglow nanoparticles could effectively eliminate the interference of background signals, providing a new method for highly sensitive and selective detection of cholesterol in biological samples.