Catalytic chemiluminescent detection of cholesterol in serum with Cu_2-x Se semiconductor nanoparticles

It is very important to be able to accurately and rapidly measure the cholesterol level in the human body, as cholesterol is associated with various diseases, such as Alzheimer's disease. In this work, a novel method of detecting cholesterol using chemiluminescence (CL) based on a newly prepared semiconductor catalyst, Cu_2-x Se nanoparticles (Cu_2-x Se NPs), was developed. It was found that the Cu_2-x Se NPs strongly enhanced the CL signal by producing a large number of reactive oxygen species (ROS) in the luminol-Cu_2-x Se NPs system. Based on the UV-vis-NIR absorption spectra, zeta potential, CL spectrum, and an investigation of the ROS, a possible mechanism for the CL was proposed. This CL-based method was successfully applied to determine cholesterol. It was found that the enhanced CL was proportional to the concentration of cholesterol over the range of 82 nM to 1.96 μM with a detection limit of 0.062 nM, and that added cholesterol was successfully detected in human serum with a mean recovery of 97 %.