CAJ | 학술논문

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5.0×10-10~5.0×10-8 mol/ L 的范围内,AQMS 的峰电流变化值(△Ipa )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6.0×10-11 mol/ L。
구건료일충기우석묵희(GR)-은곤화합물(AQMS)재핵산괄체표면층층조장적 Pb2+전화학전감기。장수식유구기적 Pb2+핵산괄체(apt)고정재금전겁표면,연후이용 GR 여 apt 감기지간적π-π작용,장 GR 흡부재 apt 수식전겁표면,병용우전활성분자 AQMS 적조장화전화학신호적방대。당목표분석물(Pb2+)존재시,Pb2+유도 apt 전변위은정적 G-사련체결구,사득 GR 련동신호분자 AQMS 종전겁표면탈락,전화학신호강저,종이실현대 Pb2+적감측。결과표명,전감기대 Pb2+구유흔호적특이식별성,차 Pb2+농도재5.0×10-10~5.0×10-8 mol/ L 적범위내,AQMS 적봉전류변화치(△Ipa )여 Pb2+농도대수(lgCPb2+)정현량호적선성관계。근거3σ,계산득검출한체도6.0×10-11 mol/ L。
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.