基于酶辅助目标物循环及金属有机框架材料的电化学链霉素传感器

Electrochemical streptomycin biosensor based on enzyme-assisted target recycling and metal-organic frame material

随着抗生素在治疗细菌感染及促进动物生长方面的广泛使用,抗生素残留问题给消费者健康带来了潜在威胁。由于日常生活中牛奶消费量与日俱增,而传统的抗生素检测方法大多具有样品前处理繁琐、检测时间长或仪器价格昂贵等局限性,因此有必要发展一种有效的牛奶中抗生素检测方法。研究构建了一种基于酶辅助目标物循环信号放大策略及金属有机框架材料(MOF)修饰电极的高灵敏电化学适体(Apt)传感器,实现了以牛奶中链霉素(STR)为模型分析物的灵敏检测。目标物STR被磁珠表面dsDNA中的STR Apt特异性识别,形成3’端暴露的Apt-STR复合物,促使发生核酸外切酶Ⅰ(ExoⅠ)辅助的STR循环参与生物识别过程,释放出大量信号探针。通过MOF修饰电极吸附信号探针,获得放大的电化学信号输出,以此为STR的定量依据。分析结果表明,该传感器具有低至0.2ng/mL的检出限、良好的选择性及应用于实际牛奶样品中STR的检测能力。该研究提出了一种有效的抗生素检测方法,为食品监测领域提供了一定程度的方法学支撑和技术支持。

With the wide application of antibiotics for bacterial infection therapy and the promotion of animal growth,antibiotic residues in food pose a potential threat to peopl’s health.Considering the increasing consumption of milk in our daily life,it is necessary to develop an effective method for the detection of antibiotics in milk.Most of the traditional antibiotic detection methods encounter some difficulties,such as complexity of sample pretreatment,long detection time and the high cost of equipment.In this study,a highly sensitive electrochemical aptamer(Apt)sensor based on enzyme-assisted target recycling signal amplification and metal-organic frame material(MOF)-modified electrode was developed,which realized the sensitive detection of antibiotics by using streptomycin(STR)in milk as model analyte.The target STR was specifically recognized by STR Apt in dsDNA immobilized on the magnetic bead surface,forming Apt-STR complex with an exposed 3’termini,promoting the exonucleaseⅠ(ExoⅠ)-assisted STR to repeatedly participate in the biorecognition process,and releasing a large number of signal probes.The amplified electrochemical signal output was obtained by adsorption of signal probes with a MOF-modified electrode,which was used for STR quantitation.The analytical results show that the sensor has a detection limit of 0.2ng/mL,good selectivity and the detection ability of STR in real milk samples.In this paper,an effective antibiotic detection method was developed to provide a certain degree of methodological and technical support for food monitoring.