锌/钴双金属无限配位聚合物纳米酶催化比色法快速检测单增李斯特菌

Rapid detection of Listeria monocytogenes by Zn/Co-bimetal infinite coordination polymers nanozymes-based catalytic colorimetry

中文关键词:  锌/钴双金属无限配位聚合物  适配体  单增李斯特菌  纳米酶  比色法

英文关键词:Zn/Co-bimetal infinite coordination polymers  aptamers  Listeria monocytogenes  nanozymes  colorimetry

中文摘要:

      目的 基于锌/钴双金属无限配位聚合物(Zn/Co-bimetal infinite coordination polymers, Zn/Co-ICPs)构建快速检测单增李斯特菌的纳米酶催化比色法。方法 基于Zn/Co-ICPs过氧化物模拟酶活性、核酸适配体对类酶活性的增强作用及特异性识别能力, 以3,3’,5,5’-四甲基联苯胺(3,3’,5,5’-tetramethylbenzidine, TMB)为催化显色底物, 建立Zn/Co-ICPs纳米酶催化比色法, 对Zn/Co-ICPs的形貌和结构进行表征, 并考察适配体浓度、pH、温度和反应时间等因素对催化效果的影响, 并将该方法应用于饮用水和冷冻巴沙鱼样品中单增李斯特菌的测定。结果 在优选的条件下, 单增李斯特菌的浓度与蓝色显色产物氧化型TMB (oxidized TMB, oxTMB)在652 nm处的吸光度呈负相关关系。该方法的线性范围为3.2×102~1.0×105 CFU/mL, r2为0.9964, 检出限(limit of detection, LOD)为1.5×102 CFU/mL。加标回收率为90.7%~108.7%, 相对标准偏差为0.17%~7.20%。结论 该方法无需使用复杂昂贵的仪器即可实现可视化检测, 且检测速度快、准确度高、选择性好, 在复杂样品快速分析中具有一定潜力。

英文摘要:

      Objective To establish a catalytic colorimetry for the rapid detection of Listeria monocytogenes based on Zn/Co-bimetal infinite coordination polymers (Zn/Co-ICPs) nanozymes. Methods Firstly, a Zn/Co-ICPs nanozymes-based catalytic colorimetry was established with 3,3’,5,5’-tetramethylbenzidine (TMB) as catalytic chromogenic substrate based on the peroxidase-mimicking activity of Zn/Co-ICPs nanoparticles, and the functional nucleic acid aptamers for enhancing the peroxidase-mimicking activity and specific recognizing the analytes. Secondly, the morphology and structure of Zn/Co-ICPs were characterized, and the effects of aptamers concentration, pH, temperature and reaction time on catalytic effect were investigated. Finally, the method was applied to the determination of Listeria monocytogenes in drinking water and frozen Basa fish samples. Results Under the optimal conditions, the concentration of Listeria monocytogenes was negatively correlated with the absorbance of blue chromogenic product oxidized TMB (oxTMB) at 652 nm. The linear range of the colorimetric method was 3.2×102?1.0×105 CFU/mL, with the r2 of 0.9964 and the limit of detection (LOD) of 1.5×102 CFU/mL. The recoveries were 90.7%?108.7%, with the relative standard deviations of 0.17%?7.20%. Conclusion The proposed method can realize visual detection without complex and expensive instruments, and has the advantages of rapidness detection, high accuracy and good selectivity, which exhibiting potential promising for rapid analysis of complex samples.