The fluorescence quenching of norfloxacin nicotinate to thioglycolic acid stabilized CdTe quantum dots (QDs) has been systematically investigated by using CdTe QDs as a fluorescence probe. On the basis of that, a sensitive method for the determination of norfloxacin nicotinate was developed. The linear equation was DF＝26.6206c－20.8273 (μg/mL) and its linear range was 0.10～90 μg/mL with correlation coefficient of 0.997. The limit of detection was 2.50×10^－2 μg/mL. Then the proposed new method was applied to measure the quantity of real sample (such as norfloxacin nicotinate solid powder), compared with the labeled amount, the accuracy was within 93.0%～104.0% and the RSD value for every sample five times determinations was or lower than 4.2%. This new method shows a bright application prospect for detection of norfloxacin nicotinate due to its several advantages such as accurate, high sensitivity, and wide detection range while compared with traditional ultraviolet spectrophotometry.

Key words: quantum dot, norfloxacin nicotinate, fluorescence quenching