1. Department of Chemistry, Nanchang University, Nanchang, 330031, China
Abstract:
We report on a simple strategy for the determination of zinc ion by using surface-modified quantum dots. The probe consists of manganese-doped quantum dots made from zinc sulfide and capped N-acetyl-L-cysteine. The particles exhibit bright yellow-orange emission with a peak at 598?nm which can be attributed to the 4T1→6A1 transition of Mn(II). This bright fluorescence is effectively quenched by modifying the sulfur anion which suppresses the radiative recombination process. The emission of the probe can then be restored by adding Zn(II) which causes the formation of a ZnS passivation layer around the QDs. The fluorescence enhancement caused is linear in the 1.25 to 30?μM zinc concentration range, and the limit of detection is 0.67?μM.
Figure
A “turn-on” fluorescent probe based on manganese-doped zinc sulfide quantum dot capped with N-acetyl-L-cysteine (NAC) was obtained and using it to determine the concentration of zinc (II) according to the fluorescent enhancement in aqueous solution.