基于双发射Ce-QDs-CPNs荧光纳米探针的H_2O_2检测方法

Ratiometric fluorescent detection of H_2O_2 based on dual-emission Ce-QDs-CPNs

制备了具有双发射功能的Ce-QDs-CPNs荧光纳米探针,利用H_2O_2对Ce-QDs-CPNs双发射荧光特性的影响,建立了比率荧光检测H_2O_2的新方法。在Tris-HCl缓冲溶液中,Ce3+与ATP和QDs自组装形成配位聚合物Ce-QDs-CPNs,在310nm的激发波长下,Ce-QDs-CPNs在369和525nm处分别发射Ce(Ⅲ)和QDs的荧光峰。当存在H_2O_2时,Ce-QDs-CPNs中的Ce(Ⅲ)被氧化为Ce(Ⅳ),使得369nm处Ce(Ⅲ)的荧光减弱,而525nm处QDs的荧光保持不变。利用Ce(Ⅲ)与QDs荧光发射峰强度比值的变化实现了H_2O_2的灵敏检测,线性范围为1nmol·L-1~30μmol·L-1,检测限为0.1nmol·L-1。双发射Ce-QDs-CPNs荧光纳米探针的合成快速简便,对H_2O_2检测的灵敏度高和选择性好,此外,本方法还可用于葡萄糖的定量分析。

In this work,we synthesized novel dual-emission cerium coordination polymer nanoparticles CeQDs-CPNs in a simple and quick way,using ATP molecules and carboxyl-modified fluorescent cadmium telluride quantum dots（CdTe QDs）as the ligands to assemble with Ce3＋ions in tris（hydroxymethyl）aminomethane hydrochloric（Tris-HCl）solution.The prepared Ce-QDs-CPNs exhibited dual-emission peaks at369 nm from Ce（Ⅲ）and 525 nm from QDs,respectively.In the presence of H2O2,the Ce（Ⅲ）of Ce-QDsCPNs was oxidized to Ce（Ⅳ）,leading to the quenching of the fluorescence（I369）of Ce（Ⅲ）,while the fluorescence of QDs（I525）was almost unchanged.Therefore,QDs can be used as an internal reference to efficiently avoid the environmental interferences.Under the optimal conditions,agood linear relationship between the fluorescence intensity ratio（I369/I525）of Ce-QDs-CPNs and the concentration of H2O2 is obtained within the range from 1 nM to 30μM,with a low detection limit of 0.1 nM.In this method,the synthesis of dual-emission nano-fluorescent probe is rapid and simple,and the ratio fluorescence detection of H2O2 has high sensitivity,selectivity and wide linear range.