Ion-mediated self-assembly of Cys-capped quantum dots for fluorescence detection of As(iii) in water
Ion-mediated self-assembly of Cys-capped quantum dots for fluorescence detection of As(iii) in water
复制标题
离子介导的 Cys 封端量子点自组装用于水中 As(iii) 的荧光检测
DOI：
10.1039/d0ay01144d
复制
发表时间：
2020
影响因子：
3.1
通讯作者：
Liu Jianbo
中科院分区：
文献类型：
--
作者：
Wu Yingben;Liu Yan;Liu Huizhi;Liu Biao;Chen Wei;Xu Lijuan;Liu Jianbo
基于半胱氨酸（Cys）封端的量子点（QDs）的离子介导自组装和荧光自猝灭，发展了一种灵敏的As（III）离子检测方法。采用水热法制备了多种Cys修饰的核壳结构CdTe/CdS量子点。基于As（III）离子与锚定在量子点上的胱氨酸基团之间的配位结合，添加As（III）离子导致Cys-capped量子点的自组装，这伴随着荧光自猝灭。荧光响应归因于量子点聚集体的激子能量转移。离子介导的荧光猝灭被进一步用于水中As（III）离子的定量测定。检测As（III）离子的检测限（LOD）为10 ng L-1（3σ法），线性范围为14至70 ng L-1。该系统进行了评估，使用一系列的干扰目标，并表现出高选择性后，添加掩蔽剂。最后，该方法被成功地用于检测砷（III）在一个真实的水样。该方法灵敏度高、专属性强，在湖泊、河流中重金属离子的定量分析中具有良好的应用前景。
A sensitive As(III) ion detection method has been developed based on ion-mediated self-assembly of cysteine (Cys)-capped quantum dots (QDs), and fluorescence self-quenching. A variety of Cys-capped core/shell CdTe/CdS QDs were prepared via hydrothermal methods. Based on the coordination binding between the As(III) ion and cystine groups anchored on the QDs, addition of As(III) ions led to self-assembly of the Cys-capped QDs, which was accompanied by fluorescence self-quenching. The fluorescence response was attributed to the exciton energy transfer of the QD aggregates. The ion-mediated fluorescence quenching was further exploited for quantitative determination of As(III) ions in water. A limit of detection (LOD) of 10 ng L−1 (3σ method) and a linear range from 14 to 70 ng L−1 were obtained for the sensing of As(III) ions. The system was evaluated using a series of interference targets, and demonstrated high selectivity after addition of mask agents. Finally, the proposed method was successfully employed for the detection of As(III) in a real water sample. The method was sensitive and specific, and shows great promise in quantitative determination of heavy metal ions in lakes and rivers.