基于AuPtRh纳米酶的比色适体传感器快速检测河豚毒素

Rapid detection of tetrodotoxin by colorimetry sensor based on AuPtRh nanoenzyme

中文关键词:  核酸适配体  纳米酶  AuPtRh  比色法  河豚毒素

英文关键词:aptamer  nanozyme  AuPtRh  colorimetric method  tetrodotoxin

中文摘要:

      目的 构建一种基于AuPtRh纳米酶和核酸适配体的比色传感器, 用于河豚毒素的可视化、快速、灵敏检测。方法 制备基于氧化石墨烯(graphene oxide, GO)修饰的金属网(stainless steel mesh, SSM)作为捕获探针, 以及AuPtRh三金属纳米酶连接核酸适配体(aptamer)作为信号探针, 通过透射电镜、原子力显微镜、X射线衍射仪、分光光度计对制备的AuPtRh纳米酶材料进行表征, 考察纳米酶的催化动力学模型, 用制备的SSM-GO/AuPtRh-aptamer传感器捕获河豚毒素。结果 最大反应速度(Vmax)为4.66×10-8 mol/(L·s), 米氏常数(Km)为0.62 mmol/L, AuPtRh作为纳米酶与H2O2的亲和力要高于单一金属和双金属与H2O2的亲和力。加入河豚毒素后, 溶液中的AuPtRh催化3,3’,5,5’-四甲基联苯胺(3,3’,5,5’-tetramethylbenzidine, TMB)生成氧化TMB (oxTMB), 溶液由透明变为蓝色。在优化条件下, 河豚毒素在5~500 ng/L范围内与652 nm处的吸光度呈良好的线性关系, 线性方程A=0.0011C+0.1523 (r2=0.9901), 检出限为3 ng/L。以蛤蜊为实际样品, 测定加标样品中河豚毒素的含量, 加标样品的回收率范围为85.61%~122.66%。结论 SSM-GO/AuPtRh-aptamer比色传感器具有操作简单、快速、灵敏度高、成本低的特点, 在现场检测领域有较大的潜力。

英文摘要:

      Objective To construct a colorimetric sensor based on AuPtRh nanoenzyme and aptamer for visual, rapid and sensitive detection of tetrodotoxin. Methods A capture probe based on graphene oxide (GO) modified metal mesh (SSM) and a signal probe of AuPtRh nanozyme linked aptamer were prepared, respectively. Some instruments were used to character the AuPtRh nanoenzyme materials, which including transmission electron microscope, scanning microscope, X-ray diffraction and spectrophotometer. The catalytic kinetic model of the nano-enzyme was investigated, and the prepared SSM-GO/AuPtRh-aptamer sensor was used to capture tetrodotoxin. Results Maximum reaction rate (Vmax) was 4.66×10-8 mol/(L·s), and Michaelis constant (Km) was 0.62 mmol/L. The affinity of AuPtRh with H2O2 as a nanoenzyme was higher than that of single metal and bimetal. After addition of tetrodotoxin, AuPtRh in solution catalyzed the formation of oxidized TMB (oxTMB) from 3,3’,5,5’-tetramethylbenzidine (TMB), and the solution turned from transparent to blue. Under optimized conditions, there was a good linear relationship between the concentration of tetrodotoxin and the absorbance at 652 nm in the range of 5-500 ng/L. The linear equation was A=0.0011C+0.1523 (r2=0.9901), and the limit of detection was 3 ng/L. The content of tetrodotoxin in the spiked samples was determined by using clams as actual samples. The recoveries of spiked samples ranged from 85.61% to 122.66%. Conclusion In conclusion, the AuPtRh-aptamer/SSM-GO-based colorimetric biosensor possesses the characteristics of simple operation, high sensitivity and low cost. It has great potential in on-site analysis.