摘要
构建了一种基于石墨烯(GR)-蒽醌化合物(AQMS)在核酸适体表面层层组装的Pb2+电化学传感器。将修饰有巯基的Pb2+核酸适体(apt)固定在金电极表面,然后利用GR与apt碱基之间的π-π作用,将GR吸附在apt修饰电极表面,并用于电活性分子AQMS的组装和电化学信号的放大。当目标分析物(Pb2+)存在时,Pb2+诱导apt转变为稳定的G-四联体结构,使得GR连同信号分子AQMS从电极表面脱落,电化学信号降低,从而实现对Pb2+的监测。结果表明,传感器对Pb2+具有很好的特异识别性,且Pb2+浓度在5.0×10!10~5.0×10!8mol/L的范围内,AQMS的峰电流变化值(ΔIpa)与Pb2+浓度对数(lgCPb2+)呈现良好的线性关系。根据3σ,计算得检出限达到6.0×10!11mol/L。
An electrochemical aptasensor forPb^2＋was constructed based on the layer-by-layer assembly of graphene（GR） and anthraquinone-2-sulfonic acid sodium salt（AQMS） on the surface ofPb^2＋aptamer. The mercapto-modifiedPb^2＋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 withPb^2＋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 ofPb^2＋ions was constructed. Under the optimal experimental conditions,the attenuation of peak currents（ΔIpa） showed linear relationship with the logarithm ofPb^2＋concentrations（lgCPb^2 ＋） over the range from 5.0 ×10^-10to 5. 0 × 10^-8mol / L. The detection limit was estimated to be 6. 0 × 10^-11mol / L.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2014年第6期853-858,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.21275127)
福建省自然科学基金(No.2011J01059)
"福建省高等学校新世纪优秀人才支持计划"(No.JA12204)项目资助~~
