检测风疹病毒IgM抗体石墨烯/多壁碳纳米管电化学传感器的研制

摘要

目的 研制基于石墨烯/多壁碳纳米管检测风疹病毒IgM抗体(RV-IgM)的电化学传感器,并对其分析性能进行评价.方法 将风疹抗原固定于经氧化态石墨烯(GS)、壳聚糖(CHI)、多壁碳纳米管(MWCNT)、1-丁基-3-甲基咪唑六氟磷酸盐([BMIM][PFd-NH2)、金纳米离子、硫堇纳米材料等生物材料层层修饰的丝网印刷电极表面,并用辣根过氧化物酶进行封闭制得研究所用的电化学传感器.使用循环伏安法对层层修饰后的传感器电极进行测试,并对传感器进行优化实验,确定传感器的最佳实验条件.在最佳实验室条件下,对传感器的分析性能进行评价.结果 裸电极经多种生物材料层层组装后,电极峰电流逐渐增大;包被抗原及辣根过氧化物酶后,电极响应电流减弱.传感器的最佳pH值及H2O2浓度分别为7.0和8.0 mmol/L,最佳孵育温度及时间分别为35.0℃和30 min.传感器检测RV-IgM的重复性精密度及日间精密度分别为3.4％、4.9％;线性范围为0.1～300 pg/mL,检出限为40 fg/mL;回收率为97.5％,抗干扰性强.结论 在最佳实验条件下,组装电化学传感器与目前现有的检测风疹病毒方法比较,具有灵敏度高、精密度和正确度较好、且快速简便、可定量的优点.%Objective To develop a electrochemical sensor based on multiwalled carbon nanotube-graphene for detection of the rubella virus IgM antibody and to evaluate its analytical performance.Methods Oxidized graphene (GS),chitosan (CHI),multi-wall carbon nano-tubes (MWCNT),1-butyl-3-methylimidazolium hexafluorophosphate (six-[BMIM][PF6]NH2),gold nanoparticles and thionine biological nanomaterial were used as materials to modify screen printing electrode by layer-by-layer self-assembly and then rubella antigen was immobilized on the assembled electrode surface,afterwards coated by horseradish peroxidase and eventually formed the electrochemical sensor used in this study.The layerby-layer assembled electrode was scanned by cyclic voltammetry to detect its electrochemical performance.The optimum experimental conditions of the sensor were obtained by optimization experiments.The analytical performance of the sensor was evaluated under the optimum experimental conditions.Results After the bare electrode was assembled with above-mentioned materials,the peak current and conductivity of the electrode gradually increased,and the response current gradually decreased after being coated by antigen and horseradish peroxidase.The optimum pH value and H2O2 concentration were 7.0 and 8.0 mmol/L respectively.The optimum incubation temperature and time were 35.0℃ and 30 minutes respectively.The repeatability precision and inter-day precision of the detection of rubella virus IgM antibody were 3.4％ and 4.9％ respectively,the linear range was 0.1-300 pg/mL,the detection limit was 40 fg/mL,the recovery rate was 97.5％.And at the same time,the sensor had a good anti-interference performance.Conclusion Under the optimum experimental conditions,the assembled electrochemical sensor for detection of rubella virus has the advantages of higher sensitivity,better precision and accuracy,the rapid and simple operation and also quantifiability compared with the existing methods.