基于溴化银-银-碳纳米管复合物与核酸适配体的阴极光电化学传感器检测赭曲霉素A  

Determination of Ochratoxin A Using a Cathodic Photoelectrochemical Sensor Based on AgBr-Ag-CNTs Composite and Aptamer

作　　者：周建红 令玉林 曾伯平[1] 张衡 邓克勤[3] ZHOU Jian-hong;LING Yu-lin;ZENG Bo-ping;ZHANG Heng;DENG Ke-qin(College of Biological and Agricultural Science and Technology,Zunyi Normal University,Zunyi 563006,China;College of Resources and Environment,Zunyi Normal University,Zunyi 563006,China;School of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]遵义师范学院生物与农业科技学院,贵州遵义563006 [2]遵义师范学院资源与环境学院,贵州遵义563006 [3]湖南科技大学化学化工学院,湖南湘潭411201

出　　处：《分析测试学报》2022年第8期1253-1258,共6页Journal of Instrumental Analysis

基　　金：遵市科合HZ字(2022)134号;贵州省省级科技计划项目(黔科合基础-ZK[2022]一般572);2021年“乡村振兴”专项(黔教合KY字[2012]017-18号);湖南省教育厅重点科研基金项目(21A0295);遵义师范学院博士基金项目(遵师BS[2020]02号);赤水河流域环境保护与山地农业发展人才基地开放基金项目。

摘　　要：该研究利用水热法制备了一种新的溴化银-银-碳纳米管(AgBr-Ag-CNTs)复合材料,并通过扫描电子显微镜、X-射线衍射和X-射线光电子能谱对其进行表征。以AgBr-Ag-CNTs作为光电阴极,相比于单一的AgBr和二元的AgBr-Ag复合材料,其具有更高的光电化学活性。采用K_(3)[Fe(CN)_(6)]作为光电子受体能进一步提高光电流信号。基于AgBr-Ag-CNTs为光电阴极传感基底,构建了一种灵敏检测赭曲霉素A(OTA)的核酸适配体传感器。对目标物的线性浓度范围为4.0 pg/mL~2.5 ng/mL,相关系数(r2)为0.994,检出限为1.5 pg/mL。该传感器制备简单、成本低、灵敏度高、抗干扰强,对样品检测的回收率为92.0%~108%,可用于实际样品中OTA的分析。Photocathode-based sensors possess the advantages of high selectivity and anti-interference in real sample detection,though photocathode produces low photocurrent signal and gives rise to poor sensitivity.Herein,a novel silver bromide-silver-carbon nanotubes(AgBr-Ag-CNTs)composite was synthesized by solvothermal method,and was characterized by scanning electronic microscopy,Xray diffraction and X-ray photoelectron spectroscopy.Because reduced Ag has revealed localized sur⁃face plasmon resonance effect(LSPR),it can amplify light absorption efficiency.Furthermore,CNTs could optimize the electric field near metallic Ag,strengthen light absorption and improve the separa⁃tion efficiency of photo-generated carriers.Thus AgBr-Ag-CNTs displayed an better cathodic photo⁃electrochemical activity,compared with AgBr or AgBr-Ag.With K_(3)[Fe(CN)_(6)]as photoelectron ac⁃ceptor,the photocurrent response could be further increased.To develop the practicality of AgBr-Ag-CNTs,an ochratoxin A(OTA)aptasensor was constructed by using AgBr-Ag-CNTs as photo⁃cathodic sensing interface,an aptamer as target recognition site,and K_(3)[Fe(CN)_(6)]as photoelectron acceptor.Since the aptamer/OTA complex has a rigid structure with weak conductivity,it could effec⁃tively block the absorption of light with the sensing interface,inhibit the transfer of photoelectrons to⁃ward electron receptors,and reduce the photocurrent signal.Based on the changed photocurrent as signal,the sensor showed a wide linear response from 4.0 pg/mL to 2.5 ng/mL(r2=0.994)and a low detection limit of 1.5 pg/mL.It was used for detection of OTA in real samples,with recoveries of 92.0%-108%.This work provided a novel photoelectrochemical method for OTA detection,with high sensitivity,specificity and good anti-interference.

关 键 词：溴化银-银-碳纳米管 光电阴极传感器 核酸适配体 赭曲霉素A 

分 类 号：O657.1[理学—分析化学] O614.12[理学—化学]