College of Public Health, University of South China, Hengyang, 421001, People's Republic of China.
Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Road, Guangzhou, 510630, China.
Mikrochim Acta. 2019 Jul 9;186(8):519. doi: 10.1007/s00604-019-3625-0.
A dually responsive fluorescent probe for determination of U(IV) and mercury(II) ions was synthesized. The probe consists of a cytosine-rich hairpin DNA loaded with silver nanoclusters (DNA-AgNCs). The fluorescence of the AgNCs is found to be quenched by UO(II) at pH 5.0 and Hg(II) at pH 7.0 due to combined static and dynamic quenching. Under the optimal conditions, the green fluorescence of the DNA-AgNCs, best measured at excitation/emission wavelengths of 420/525 nm, decreases in the 4.0 to 75 pM UO(II) concentration range, and in the 0.3 to 8.0 nM Hg(II) concentration range. The respective detection limits are as low as 1.8 pM and 0.1 nM. The method was successfully applied to the determination of UO(II) and Hg(II) in (spiked) pond and taps waters and in soil extracts. Graphical abstract A label-free DNA was designed to synthesize green-fluorescent silver nanoclusters (AgNCs) and used for rapid dual detection of uranyl ions (UO(II)) at pH 5.0 and of mercury ions (Hg(II)) at pH 7.0 in environmental samples.
一种用于同时测定 U(IV)和汞(II)离子的双重响应荧光探针被合成。该探针由富含胞嘧啶的发夹 DNA 负载银纳米簇（DNA-AgNCs）组成。在 pH 5.0 下，UO(II)由于静态和动态猝灭使 AgNCs 的荧光猝灭；在 pH 7.0 下，Hg(II)也会使 AgNCs 的荧光猝灭。在最佳条件下，DNA-AgNCs 的绿色荧光在 420/525nm 的激发/发射波长下测量，在 4.0 到 75 pM UO(II)浓度范围内降低，在 0.3 到 8.0 nM Hg(II)浓度范围内降低。各自的检测限低至 1.8 pM 和 0.1 nM。该方法成功应用于池塘和自来水（加标）以及土壤提取物中 UO(II)和 Hg(II)的测定。
