Graphene and Anthraquinone-2-sulfonic Acid Sodium Based Electrochemical Aptasensor for Pb2+
10.3724/SP.J.1096.2014.30884
- VernacularTitle:基于石墨烯和蒽醌-2-磺酸钠的 Pb2+核酸适体电化学传感器
- Author:
Cai GAO
;
Le HANG
;
Xiaolei LIAO
;
Fei GAO
;
Qingxiang WANG
- Publication Type:Journal Article
- Keywords:
Lead ion;
Aptasensor;
Graphene;
Anthraquinone-2-sulfonic acid sodium salt
- From:
Chinese Journal of Analytical Chemistry
2014;(6):853-858
- CountryChina
- Language:Chinese
-
Abstract:
An electrochemical aptasensor for Pb2+ was constructed based on the layer-by-layer assembly of graphene (GR) and anthraquinone -2-sulfonic acid sodium salt (AQMS) on the surface of Pb2+ aptamer. The mercapto-modified Pb2+ aptamer was first anchored on a gold electrode. Then the highly conductive material of GR was adsorbed on apt through the unique π-π stacking interaction, which was further used for the assembly and signal amplification of the electroactive AQMS. Upon interaction with Pb2+ ions, the apt on the aptasensor undergone conformational switch from a single-stranded form to the G-quadruplex structure, causing the GR assembled with AQMS releasing from the electrode surface into solution. As a result, the electrochemical signal of AQMS on the aptasensor was substantially reduced. Base on this concept, a useful platform for detection of Pb2+ ions was constructed. Under the optimal experimental conditions, the attenuation of peak currents (△Ipa ) showed linear relationship with the logarithm of Pb2+ concentrations (lgCPb2+) over the range from 5. 0×10-10 to 5. 0×10-8 mol/ L. The detection limit was estimated to be 6. 0×10-11 mol/ L.
