Cui Lin, Wu Jie, Li Jie, Ju Huangxian
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210093, P. R. China.
Anal Chem. 2015 Oct 20;87(20):10635-41. doi: 10.1021/acs.analchem.5b03287. Epub 2015 Oct 9.
An efficient electrochemical sensor was presented for lead cation detection using a DNA functionalized iron-porphyrinic metal-organic framework (GR-5/(Fe-P)n-MOF) as a probe. The newly designed probe showed both the recognition behavior of GR-5 to Pb(2+) with high selectivity and the excellent mimic peroxidase performance of (Fe-P)n-MOF. In the presence of Pb(2+), GR-5 could be specifically cleaved at the ribonucleotide (rA) site, which produced the short (Fe-P)n-MOF-linked oligonucleotide fragment to hybridize with hairpin DNA immobilized on the surface of screen-printed carbon electrode (SPCE). Because of the mimic peroxidase property of (Fe-P)n-MOF, enzymatically amplified electrochemical signal was obtained to offer the sensitive detection of Pb(2+) ranging from 0.05 to 200 nM with a detection limit of 0.034 nM. In addition, benefiting from the Pb(2+)-dependent GR-5, the proposed assay could selectively detect Pb(2+) in the presence of other metal ions. The SPCE based electrochemical sensor along with the GR-5/(Fe-P)n-MOF probe exhibited the advantages of low-cost, simple fabrication, high sensitivity and selectivity, providing potential application of on-site and real-time Pb(2+) detection in complex media.
提出了一种高效的电化学传感器，用于检测铅阳离子，该传感器使用DNA功能化的铁卟啉金属有机框架（GR-5/(Fe-P)n-MOF）作为探针。新设计的探针既表现出GR-5对Pb(2+)的高选择性识别行为，又具有(Fe-P)n-MOF出色的模拟过氧化物酶性能。在Pb(2+)存在的情况下，GR-5可在核糖核苷酸（rA）位点特异性切割，产生短的(Fe-P)n-MOF连接的寡核苷酸片段，与固定在丝网印刷碳电极（SPCE）表面的发夹DNA杂交。由于(Fe-P)n-MOF的模拟过氧化物酶特性，获得了酶促放大的电化学信号，可实现对0.05至200 nM的Pb(2+)进行灵敏检测，检测限为0.034 nM。此外，得益于依赖Pb(2+)的GR-5，所提出的检测方法能够在其他金属离子存在的情况下选择性地检测Pb(2+)。基于SPCE的电化学传感器与GR-5/(Fe-P)n-MOF探针一起，具有低成本、制备简单、灵敏度高和选择性好等优点，为在复杂介质中现场实时检测Pb(2+)提供了潜在应用。
