A multifunctional fluorescent aptamer probe for highly sensitive and selective detection of cadmium(II)

作者：Zhu, Yu-Feng; Wang, Yong-Sheng^*; Zhou, Bin; Yu, Jun-Hui; Peng, Li-Lan; Huang, Yan-Qin; Li, Xue-Jiao; Chen, Si-Han; Tang, Xian; Wang, Xiao-Feng

来源：Analytical and Bioanalytical Chemistry, 2017, 409(21): 4951-4958.

DOI：10.1007/s00216-017-0436-1

• Multifunctional aptamer probe
• Cadmium(II)
• Conformational switching
• Mechanism certification
• Stem-loop structure
• Fluorescence strategy

We report a highly sensitive and selective strategy for Cd(II) assay using a singly labeled multifunctional probe consisting of a Cd(II)-specific aptamer (CAP), which acted as a recognition element for Cd(II) and a signal reporter. The presence of Cd(II) can induce the conformational switching of the CAP, accompanied by a change in fluorescence intensity. Thereby, a fluorescence strategy for Cd(II) assay was established. The proposed method has a detection limit of 2.15 nM, which is much lower than the detection limits reported in related literature. This strategy involves only an aptamer probe, and the use of such a G(4)-based quencher avoids the dual labeling of the CAP with fluorophore/quencher units. It is obviously more convenient and economical than the other aptamer-based biosensors for Cd(II) detection. The mechanism by which Cd(II) induces the CAP to change from a random coil sequence to a stem-loop structure was studied in a series of control experiments. This strategy would be helpful in the design of a sensitive analytical platform for various target assays in environmental and biomedical fields.

• 出版日期2017-8
• 单位南华大学