Li Qianyun, Jia Yongmei, Feng Zongcai, Liu Fang
School of Materials Science and Engineering, South China University of Technology Guangzhou 510640 Guangdong China
Institute for Advanced Materials, Lingnan Normal University Zhanjiang 524048 Guangdong China.
RSC Adv. 2018 Nov 19;8(68):38929-38934. doi: 10.1039/c8ra07903j. eCollection 2018 Nov 16.
Lead is a highly toxic heavy metal, and various functional nucleic acid (FNA)-based biosensors have been developed for the detection of Pb in environmental monitoring. However, most fluorescence biosensors that have been reported were designed on the basis of a double-labeled (fluorophore and quencher group) DNA sequence, which not only involved an inconvenient organic synthesis but also restricted their wider use in practical applications. Here, we utilized a G-rich DNA sequence as a recognition probe and conjugated fluorene (CF) to develop a fluorescence sensor without a quencher based on the aggregation-caused quenching (ACQ) effect. In the presence of Pb, the degree of aggregation of CF was reduced because Pb induced the formation of a G-quadruplex structure of the CF-DNA probe, and the fluorescence signal increased with the concentration of Pb (0-1 μM), with a limit of detection of 0.36 nM. This fluorescent probe without a quencher enables the sensitive and selective detection of Pb. On the basis of these advantages, the CF-DNA probe represents a promising analytical method for detecting Pb.
铅是一种剧毒重金属，在环境监测中，人们已开发出各种基于功能核酸（FNA）的生物传感器用于检测铅。然而，已报道的大多数荧光生物传感器是基于双标记（荧光团和猝灭基团）DNA序列设计的，这不仅涉及不便的有机合成，还限制了它们在实际应用中的更广泛使用。在此，我们利用富含G的DNA序列作为识别探针，并结合芴（CF），基于聚集诱导猝灭（ACQ）效应开发了一种无猝灭剂的荧光传感器。在铅存在的情况下，CF的聚集程度降低，因为铅诱导了CF-DNA探针形成G-四链体结构，并且荧光信号随铅浓度（0 - 1μM）的增加而增强，检测限为0.36 nM。这种无猝灭剂的荧光探针能够灵敏且选择性地检测铅。基于这些优点，CF-DNA探针是一种很有前景的铅检测分析方法。
