In this paper, we proposed a simple and sensitive assay of phenolic compounds (PCs) using 3-mercaptocarboxylic acid (MPA) modified CdTe nanocrystals (CdTe NCs), which contain abundant carboxylic groups (-COOH) and are water-soluble, stable and biocompatible. The effects of surfactants on the CdTe/H(2)O(2) chemiluminescence (CL) system were investigated. It is found that the addition of Tween 20 into the system could induce a significant enhancement on CL intensity. PCs were observed to inhibit the CL signal of the CdTe/H(2)O(2)/Tween 20 system and determined by the proposed method. The CL mechanism was also discussed briefly based on the photoluminescence (PL) and CL spectra.