农业工程学报
農業工程學報
농업공정학보
2014年
12期
278-283
,共6页
蒋雪松%王维琴%卢利群%郑丹丹%陈卉卉%许林云
蔣雪鬆%王維琴%盧利群%鄭丹丹%陳卉卉%許林雲
장설송%왕유금%로리군%정단단%진훼훼%허림운
免疫传感器%农药%农产品%毒死蜱%检测%电化学阻抗谱%微天平
免疫傳感器%農藥%農產品%毒死蜱%檢測%電化學阻抗譜%微天平
면역전감기%농약%농산품%독사비%검측%전화학조항보%미천평
immunosensors%pesticides%agriculture products%chlorphrifos%detection%impedance spectroscopy%pesticide residues%microbalance
研究了一种无标记的电化学免疫传感器,用于农产品中的毒死蜱农药残留的快速检测。将毒死蜱人工抗原作为生物识别元件固定在金电极的表面,采用间接竞争法原理,样品中的被测组分与电极上的固定化包被抗原竞争性结合溶液中的抗体。抗体抗原结合反应通过电化学阻抗谱和石英晶体微天平进行表征。将该免疫传感器用于检测青菜、苹果等农产品中的毒死蜱农药残留。结果表明,此免疫传感器灵敏度好、准确度高;对毒死蜱农药的检测限为0.01μg/mL,回收率大于85%,检测时间小于1 h,变异系数小于5%,传感器经过再生处理后能重复使用,经济性较好。该研究可为实现快速检测农产品中农药残留传感器的商品化提供参考。
研究瞭一種無標記的電化學免疫傳感器,用于農產品中的毒死蜱農藥殘留的快速檢測。將毒死蜱人工抗原作為生物識彆元件固定在金電極的錶麵,採用間接競爭法原理,樣品中的被測組分與電極上的固定化包被抗原競爭性結閤溶液中的抗體。抗體抗原結閤反應通過電化學阻抗譜和石英晶體微天平進行錶徵。將該免疫傳感器用于檢測青菜、蘋果等農產品中的毒死蜱農藥殘留。結果錶明,此免疫傳感器靈敏度好、準確度高;對毒死蜱農藥的檢測限為0.01μg/mL,迴收率大于85%,檢測時間小于1 h,變異繫數小于5%,傳感器經過再生處理後能重複使用,經濟性較好。該研究可為實現快速檢測農產品中農藥殘留傳感器的商品化提供參攷。
연구료일충무표기적전화학면역전감기,용우농산품중적독사비농약잔류적쾌속검측。장독사비인공항원작위생물식별원건고정재금전겁적표면,채용간접경쟁법원리,양품중적피측조분여전겁상적고정화포피항원경쟁성결합용액중적항체。항체항원결합반응통과전화학조항보화석영정체미천평진행표정。장해면역전감기용우검측청채、평과등농산품중적독사비농약잔류。결과표명,차면역전감기령민도호、준학도고;대독사비농약적검측한위0.01μg/mL,회수솔대우85%,검측시간소우1 h,변이계수소우5%,전감기경과재생처리후능중복사용,경제성교호。해연구가위실현쾌속검측농산품중농약잔류전감기적상품화제공삼고。
The objective of this study was to develop a label free electrochemical immunosensor for detection of pesticide chlorpyrifos (CPF) in agricultural products. The surface modification of sensors consisted of three successive steps:1) surface cleaning;2) increasing the surface coverage of hydroxyl groups;3) silanization. The CPF hapten conjugate used as recognizing elements were immobilized on the surface of an electrode. Cyclic votammetry was investigated before and after hapten coating, which that confirmed CPF hapten could be successfully coated on the electrodes. The spiked CPF solution was diluted into various folds and mixed with an CPF antibody solution. The detection method was based on an indirect competitive reaction of a limited anti-CPF polyclonal antibody in a sample solution with immobilized hapten, and with a pesticide analyte in the sample solution. The antibody-antigen affinity interactions were investigated by impedance spectroscopy and quartz crystal microbalance. Impedance measurements were performed using a three-electrode setup, which consisted of a gold electrode as a working electrode, a platinum auxiliary electrode, and an Ag/AgCl reference electrode. For impedance measurement, a sine-modulated AC potential with an amplitude of 5mV was applied to the modified electrodes. The Faradic impedance spectra were recorded in the frequency range from 1Hz to 100 kHz, respectively. The semi-circle diameter in the Nyquist plot represented the electron-transfer resistance in an equivalent circuit, decreased with increasing analyte concentrations. For the QCM test, a crystal electrode was mounted in the base of a cylindrical test cell using an“O-ring”. One face of the crystal was exposed to the test liquid, while the other was exposed to air. After the antigen modified chips were reacted with the mixture, the variations between the initial and final resonance frequency in PBS was recorded. The signal response of the biosensing system to pesticide CPF concentrations was linear, with the range tested from 0.01-10μg/mL, with the correlation coefficient of 0.98. The result indicated that EIS was capable of monitoring the change in electron-transfer resistance resulting from anti-CPF antibody-antigen interaction. QCM was also the ideal tool for probing antigen-antibody molecular recognition. The immunosensor can be suited to the detection of pesticide residues in agricultural products, such as Chinese green vegetables and apples. The immunosensor was shown to be sensitive, accurate, rapid, and economical, thus providing a viable alternative to current pesticide detection methods. The systems can be used to determine pesticide CPF down to 0.01μg/mL. The recovery rate was more than 85 percent. The total detection time was less than 1 h. The mean within-assay variability of detected results was less than 5 percent. It can be used repeatedly after sensor generation.