纳米酶侧流免疫层析法快速检测食品中肠炎沙门氏菌

Rapid detection of Salmonella enteritidis in food by nanozyme based lateral flow immunoassay

中文关键词:  免疫层析  肠炎沙门氏菌  快速检测  纳米酶

英文关键词:lateral flow immunoassay  Salmonella enteritidis  rapid detection  nanozyme

中文摘要:

      目的 基于氧化铈修饰的金纳米棒(CeO2 modified Au nanorod, AuNR@CeO2)构建纳米酶侧流免疫层析法(lateral flow immunoassay, LFIA), 并用以检测食品中肠炎沙门氏菌。方法 采用模板法制备AuNR@CeO2纳米酶, 对纳米酶的酶促活性进行考察。将AuNR@CeO2标记抗体作为信号探针进一步构建纳米酶LFIA, 并优化其关键参数, 并利用AuNR@CeO2纳米酶的酶促活性, 催化放大试纸条的比色信号, 最后将其用于奶粉中肠炎沙门氏菌的检测。结果 成功制备了AuNR@CeO2纳米酶, 在最优条件下(2%牛血清蛋白+0.05% Tween-20的样品垫缓冲体系、0.8 mg/mL的T线抗体质量浓度和4 μL的探针使用量), 该试纸条可以实现目标菌的特异性检测, 检出限低至103 CFU/mL, 信号放大后灵敏度提高了10倍, 在人工污染奶粉样品中检出限低至103 CFU/mL。结论 本研究所制备的试纸条无需复杂仪器和专业人员即可实现目标物的检测, 且具有易操作、便携、快速的特点, 通过更换抗体类型便可用于各类食品有害物质的检测。

英文摘要:

      Objective To construct a lateral flow immunoassay (LFIA) for the detection of Salmonella enteritidis (S. enteritidis) in food based on CeO2 modified Au nanorod (AuNR@CeO2) nanozyme. Methods Firstly, AuNR@CeO2 nanozyme was synthesized via template method and its enzyme-like activity was investigated. Then, AuNR@CeO2 was labeled with anti-S. enteritidis monoclonal antibody as probe to construct nanozyme based LFIA, of which several key parameters were optimized. The enzyme-like activity of AuNR@CeO2 was utilized to catalyze and amplify original signals in LFIA. Finally, it was applied in the detection of Salmonella enteritidis in milk powder to demonstrate the applicability. Results We successfully prepared AuNR@CeO2 nanozyme. Under optimized conditions (2% bovine serum albumin +0.05% Tween-20 of sample pad buffer system, 0.8 mg/mL of antibody concentration in test line, and 4 μL of probe volume), this novel LFIA realized a detection limit of 103 CFU/mL for S. enteritidis without any cross reaction with other common foodborne pathogens. In addition, the limit of detection for S. enteritidis were identified to be 103 CFU/mL in milk powder. Conclusion Without the need of complicated instruments and professionals, this proposed LFIA has showed great promising in foodborne pathogens detection.