Peng Jun, Ling Jian, Wen Qiu-Lin, Li Yu, Cao Qiu-E, Huang Zhang-Jie, Ding Zhong-Tao
Functional Molecules Analysis and Biotransformation Key Laboratory of Universities in Yunnan Province, School of Chemical Science and Technology, Yunnan University Kunming 650091 China
Hunan Province Geological Testing Institute Changsha 410007 China.
RSC Adv. 2018 Dec 12;8(72):41464-41471. doi: 10.1039/c8ra07986b. eCollection 2018 Dec 7.
Fluorescence of DNA-templated silver nanoclusters can be enhanced by more than 100-fold by placing the nanoclusters in proximity to guanine-rich DNA sequences after hybridization. We found that the fluorescence of the guanine-enhanced silver nanoclusters is not increased with the guanine-rich DNA sequence closer to the silver nanoclusters. By studying the different numbers of mismatches in the linker sequences, we found that the presence of a single-nucleotide mismatch in the linker increases fluorescence more than the complementary nucleotide. Further study indicated the mismatch position of the linker sequence also affects the fluorescence of the hybridized DNA-Ag NCs. The evidence reported here indicated that the mismatch of the linker sequence affects the fluorescence enhancement of guanine-enhanced silver nanoclusters. We also found that DNA-Ag NCs is an excellent fluorescence sensor for cyanide, as cyanide effectively quenches the fluorescence of NCs at a very low concentration with high selectivity. Cyanide in the range from 0.10 μM to 0.35 μM could be linearly detected, with a detection limit of 25.6 nM.
通过杂交后将DNA模板化的银纳米簇置于富含鸟嘌呤的DNA序列附近，其荧光可增强100多倍。我们发现，富含鸟嘌呤的DNA序列离银纳米簇越近，鸟嘌呤增强的银纳米簇的荧光并不增加。通过研究连接子序列中不同数量的错配，我们发现连接子中单个核苷酸错配比互补核苷酸更能增加荧光。进一步研究表明，连接子序列的错配位置也会影响杂交的DNA-Ag NCs的荧光。此处报道的证据表明，连接子序列的错配会影响鸟嘌呤增强的银纳米簇的荧光增强。我们还发现，DNA-Ag NCs是一种出色的氰化物荧光传感器，因为氰化物能在非常低的浓度下以高选择性有效淬灭NCs的荧光。可以线性检测0.10 μM至0.35 μM范围内的氰化物，检测限为25.6 nM。
