基于铂纳米颗粒@金属有机骨架纳米模拟酶的无标记电化学赭曲霉毒素适体传感器的构建

Construction of a Label-free Electrochemical Ochratoxin Aptasensor Based on Pt Nanoparticles@metal-organic Framework Nanomimetic Enzyme

以具有类过氧化物酶性质的Pt NPs@Mn-MOF纳米复合材料作为电极基底,采用丝网印刷电极构建了一种无标记型电化学适体传感器,用于赭曲霉毒素(OTA)的检测.利用Pt NPs@Mn-MOF的模拟酶特性,将其作为电极基底用于捕获OTA适体链,同时催化H2O_(2)还原产生电流响应信号.OTA的引入会减少纳米酶的催化活性位点,从而导致电流信号降低.在0.01~300 ng/mL范围内,随着OTA浓度的增加,电流响应值逐渐降低;采用计时电流法检测电流响应信号,从而间接实现了对OTA的定量检测.此外,该生物传感器通过U盘式小型工作站进行检测,不仅可与电脑连接进行检测,还可与手机连接进而实现实时检测,并且其检测灵敏度高、重现性好,检出限低至3.33 pg/mL(S/N=3).该传感器可用于真实玉米样品中OTA的检测,在真菌毒素现场检测中展现出潜在的应用价值.

Pt NPs@Mn-MOF nanocomposite material with peroxidase-like properties was used as electrode substrate,and a label-free electrochemical aptasensor was constructed by screen printing electrode for the detection of ochratoxin(OTA).Utilizing the nanomimetic enzyme characteristics of Pt NPs@Mn-MOF,Pt NPs@Mn-MOF was used as an electrode substrate to capture OTA aptamer chain and catalyze the reduction of H2O_(2) to generate current response signal.The introduction of OTA can obdurate the catalytic active sites of the nanomimetic enzyme,which leads to the decrease of current signal.In the range of 0.01-300 ng/mL,the current response value decreases gradually with the increase of OTA concentration.The current response signal was detected by the chronoamperometry,so the quantitative detection of OTA was realized indirectly.In addition,the aptasensor can be detected through a small U-disk type electrochemical workstation,which can be connected to a computer or a mobile phone for real-time detection.It has high detection sensitivity and good reproducibility,and the detection limit is as low as 3.33 pg/mL(S/N=3).The constructed aptasensor can be used for OTA detection in real corn samples,and shows potential application in mycotoxin detection.