Ratiometric fluorescent probe based on carbon dots and Zn-doped CdTe QDs for detection of 6-Mercaptopurine

Due to the well-known side effects on human health caused by 6-Mercaptopurine (6-MP), it is necessary to develop a simple to operate method for determination of 6-MP. In this work, a simple and easy ratiometric fluorescence probe was fabricated based on two kind of quantum dots with different emission. The probe was composed of blue emission carbon dots (CDs) and yellow emission Zn-doped CdTe quantum dots (ZnCdTe QDs) capped with GSH. The fluorescence intensity of ZnCdTe QDs could be selectively quenched by 6-MP based on fluorescence resonance energy transfer (FRET). At the same time, the fluorescence intensity of CDs basically stayed constant, and the fluorescence intensity ratio (F445/F565) showed a linear response to the concentration of 6-MP. The designed probe of ZnCdTe QDs/CDs displayed a wide and comparable detection range from 1.0 to 100.0 μmol L−1, and the detection limit reached 0.46 μmol L−1. Furthermore, the method has been realized for monitoring the concentration of 6-MP in human serum samples.