Cucurbit[6]uril modified CdTe quantum dots fluorescent probe and its selective analysis of p-nitroaniline in environmental samples

An efficient fluorescent probe based on cucurbit[6]uril modified CdTe quantum dots (CB[6]@QDs) was prepared. This novel probe showed significant and selective fluorescence quenching and complexation capacity to p-nitroaniline, its interaction mechanism was studied by both experimental and theoretical methods. Furthermore, a fluorescent method was developed for the determination of p-nitroaniline in different environmental samples. The fluorescence intensity of CB[6]@QDs showed a good linearity response to p-nitroaniline in the concentration range of 2.5 x 10(-7)-3.0 x 10(-6) mol/L with a correlation coefficient (R-2) of 0.9976, the limit of detection (LOD) was 6 x 10(-8) mol/L and the limit of quantification (LOQ) was 2 x 10(-7) mol/L. Moreover, about 0-1.5 x 10(-6) mol/L p-nitroaniline were determined in environmental samples, the recoveries were in the range of 88-109% with the relative standard deviations (n = 3) of 1.2-4.5%. Compared with previous fluorescent methods, the present method shortened and simplified the sample pretreatment as well as enhanced the sensitivity and selectivity of analytical method. No further sample pretreatment procedure is needed and the LOD of present method was one order of magnitude less than previous fluorescent methods, showed it is a simple, selective and sensitive method.