Preparation and application of functionalized nanoparticles of CdSe capped with 11-mercaptoundecanoic acid as a fluorescence probe

A new fluorescence probe, CdSe nanocrystal has been prepared and modified with 11-mercaptoundecanoic acid [HS-(CH2)10-COOH]. The functionalized nanoparticles were characterized using transmission electron microscopy (TEM), ultraviolet–visible (UV–vis) spectroscopy and photoluminescence (PL) spectroscopy. The results demonstrate that CdSe is dispersed homogeneously in aqueous solution and well protected from the environmental oxygen. They can be used as a new fluorescence probe for lysozyme, which was simple, rapid and specific. Under the optimum condition, the response is linearly proportional to the amount of lysozyme from 0.20 to 26.0 μg ml−1, and the limit of detection is 0.115 μg ml−1. The proposed method has been applied to the determination of lysozyme in egg white, with the recovery of 96–105%.