基于电活性铁氰化镍和金属模拟酶协同催化的蛋白质电化学检测  

Electrochemical Detection of Protein Based on Electroactive Nickel Hexacyanoferrate and Metallic Mimic Enzyme Synergistic Catalytic Enhancement

作　　者：张丽娜[1] 谢西月 柴雅琴[2] ZHANG Li-na;XIE Xi-yue;CHAI Ya-qin(Jincheng Institute of Technology,Jincheng 048026,China;College of Chemistry and Chemical Engineering,Southwest University,Chongqing 400715,China)

机构地区：[1]晋城职业技术学院,山西晋城048026 [2]西南大学化学化工学院,重庆400715

出　　处：《分析测试学报》2020年第12期1515-1520,共6页Journal of Instrumental Analysis

基　　金：国家自然科学基金项目(21974108)。

摘　　要：该文设计了一种基于金属纳米模拟酶协同催化产生不溶性沉淀的“signal-off”型电化学免疫传感器用于超灵敏检测甲胎蛋白(AFP)。通过夹心免疫法将具有辣根过氧化物活性的二抗耦合物空心纳米金-铂钯纳米颗粒(HAuNPs-PtPdNPs-Ab2)固载在电活性物质铁氰化镍纳米颗粒修饰的电极上。在H2O2存在下,以AFP捕获的二抗耦合物中的HAuNPs和PtPdNPs作为辣根过氧化物模拟酶催化4-氯-1-萘酚(4-CN),并在电极界面生成不溶且不导电的沉淀物苯并-4-氯己二烯酮(4-CD),有效阻碍了电子传递,电化学信号显著降低,可用于AFP的定量检测。实验表明,该传感器对0.1 pg/mL^200 ng/mL AFP表现出良好的检测线性,检出限(S/N=3)为33 fg/mL。该传感策略具有协同催化作用,可提供一种新的多重信号放大方法用于改善传感器的灵敏度。A‘signal-off’electrochemical immunosensor was designed for the ultra-sensitive detection ofα-fetoprotein(AFP)based on the synergistic catalytic enhancement of metallic nano-mimic enzyme to produce insoluble precipitation.The hollow gold-palladium-platinum nanoparticle bioconjugates(HAuNPs-PtPdNPs-Ab2)were immobilized on the electrode modified with electroactive substance nickel hexacyanoferrate nanoparticles through sandwich-type immunoassay.In the presence of H2O2,HAuNPs and PtPdNPs as peroxidase-mimicking enzymes catalyzed 4-chloro-1-naphthol(4-CN)to generate insoluble and non-conductive precipitation benzo-4-chlorohexadienone(4-CD)at the electrode interface,thus effectively increasing the hindrance of electron transfer and leading to a significant decrease in electrochemical signal.The quantitative detection of AFP was achieved by the changes of electrochemical signal before and after the addition of AFP.Under the optimized reaction conditions,the experiment proved that the established immunosensor possessed a wider dynamic response from 0.1 pg/mL to 200 ng/mL in the detection of AFP with a low detection limit of 33 fg/mL.On the basis of the synergistic catalytic amplification,the proposed strategy could provide an effective method for multiple signal amplification to enormously improve the sensitivity of the biosensor.

关 键 词：协同催化作用 电化学免疫传感器 金属纳米材料 模拟酶 

分 类 号：O657.1[理学—分析化学] O625.3[理学—化学]