【作者】 李颖；

【导师】 邱景富； 陈安懿；

【作者基本信息】 重庆医科大学 ， 卫生检验学， 2023， 硕士

【摘要】 随着SARS-CoV-2传播性的增加和致病力的减弱,同时越来越多的人也不断感染各种奥密克戎变异株,国内疫情防控进入新阶段。基于目前的形势,人们对于SARS-CoV-2感染的检测也从需要专业人员操作且耗时较长的逆转录实时定量PCR转移到操作简单、检测快速的免疫层析法。以抗原检测为基础的免疫层析法虽然可以作为SARS-CoV-2感染的直接证据,但其灵敏度不够高,从而限制了其在疫情防控中的应用。因此,我们拟开发一种以抗原检测为基础的能够灵敏、快速检测SARS-CoV-2的方法,以满足当前疫情防控需求。电化学免疫传感器结合了免疫学方法的高特异性和电化学方法的高灵敏度,为SARS-CoV-2的检测提供了新的研究思路。传感器通过各种纳米材料修饰和微加工技术等提供一个高灵敏度和选择性的平台,而基于纳米酶修饰电极的传感平台已经成为提高免疫传感器灵敏度的一种有效手段。此外,将纳米酶修饰电极与信号标签结合共同应用于电化学免疫传感器中,可以产生良好的信号放大效果。综上,本工作基于PtPdRu纳米枝晶优良的类过氧化物纳米酶特性和优异的电催化活性,利用其修饰电极表面,制备了用于SARS-CoV-2抗原检测的简易电化学免疫传感器。该纳米酶表现出较好的电化学性能,这归因于其多孔树枝晶结构的高比表面积、良好的导电性和三金属对电流信号的协同放大作用。在SARS-CoV-2抗原存在的情况下,SiO₂标记的二抗通过典型的夹心型结构固定在电极表面,通过信号关闭型放大策略降低了对SARS-CoV-2抗原的响应电流信号,特别是在低浓度新冠蛋白存在的情况下,更容易区分不同浓度抗原之间的电化学信号。结果表明,该电化学免疫传感器对SARS-CoV-2抗原的检测范围为1.0 pg/m L～1.0μg/m L,检出限为51.74 fg/m L。该生物传感器为快速检测SARS-CoV-2提供了一种简单而灵敏的工具。更多还原

【Abstract】 With the increased transmissibility and reduced pathogenicity of SARS-CoV-2,along with the increasing number of people who continue to be infected with various Omicron variants,the epidemic prevention and control enters a new stage.Based on the current situation,the detection of SARS-CoV-2 infection has shifted from the professional and time-consuming real-time quantitative reverse transcription PCR to the simple and fast detection of immunochromatography.Although immunochromatography based on antigen detection can be used as direct evidence of SARS-CoV-2 infection,its sensitivity is not high enough,which limits its application in epidemic prevention and control.Therefore,we propose to develop an accurate and rapid detection method of SARS-CoV-2 based on antigen detection to meet the current epidemic prevention and control needs.Electrochemical immunosensor combines the high specificity of immunological method and the high sensitivity of electrochemical method,providing a new research idea for the detection of SARS-CoV-2.The sensor provides a platform of high sensitivity and selectivity through various nanomaterial modification and micromachining technology,and the sensor platform based on the modification of nanoenzyme has become an effective means to improve the sensitivity of the immunosensor.In addition,the combination of nanoenzyme modified electrode and signal label in electrochemical immunosensor can produce a good signal amplification effect.In summary,a simple electrochemical immunosensor for SARS-CoV-2 antigen detection was prepared by modifying the electrode surface with PtPdRu nanodendrites（PtPdRu NDs）based on its superior peroxide-like nanozyme properties and excellent electrocatalytic activity.The nanozyme exhibit good electrochemical performance,which is attributed to the high specific surface area of the porous dendrite structure,good electrical conductivity and the cooperative amplification of the current signal by the trimetal.In the prensence of SARS-CoV-2 antigen,SiO₂-labeled antibody are fixed on the electrode surface through a typical sandwich structure,and the response current signal to the SARS-CoV-2antigen is reduced by a signal-off amplification strategy.Especially in the presence of low concentrations of SARS-CoV-2 antigen,it is easier to distinguish the electrochemical signals between antigens of different concentrations.As a result,the proposed electrochemical immunosensor presented sensitive detection of SARS-CoV-2 antigen with linear range from 1.0 pg/m L to 1.0μg/m L and limit of detection down to 51.74 fg/m L.The proposed biosensor provide a brief but sensitive tool for rapid detection of SARS-CoV-2.更多还原