Biological activities of magnetic Au-nanoparticles have been observed to have the high biocompatibility, and a sample immunosensor model has been designed to use avidin attached Au-nanoparticles for L. monocytogenes detection. Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium) bacteria cultures were chosen for control studies. Antimicrobial activity studies have been done to identify bio-compatibility and bio-characterization of the Au-nanoparticles in our previous study and capturing efficiencies to bacterial surfaces have been also investigated.
We constructed the calibration graphs in various population density of L. monocytogenes as 2.2 × 101 to 2.2 × 106 cfu/mL and the capture efficiency was found to be 75%. After the optimization procedures, population density of L. monocytogenes and Raman signal intensity showed a good linear correlation (R2 = 0.991) between 102 to 106 cfu/mL L. monocytogenes. The presented sandwich assay provides low detection limits and limit of quantification as 12 cfu/mL and 37 cfu/mL, respectively. We also compared the experimental results with reference plate-counting methods and the practical utility of the proposed assay is demonstrated using milk samples.
It is focused on the enumeration of L. monocytogenes in milk samples and the comparision of results of milk analysis obtained by the proposed SERS method and by plate counting method stay in food agreement. In the present study, all parameters were optimized to select SERS-based immunoassay method for L. monocytogenes bacteria to ensure LOD, selectivity, precision and repeatablity.
已经观察到磁性Au纳米颗粒的生物活性具有高的生物相容性,和样品免疫传感器模型已被设计为使用抗生物素蛋白附着的Au纳米颗粒用于单核细胞增生李斯特菌的检测。金黄色葡萄球菌(S。金黄色葡萄球菌)和鼠伤寒沙门氏菌(S.鼠伤寒)细菌培养物被选择用于对照研究。在我们先前的研究中,已经进行了抗微生物活性研究以鉴定Au纳米颗粒的生物相容性和生物表征,并且还研究了对细菌表面的捕获效率。
我们构建了单核细胞增生李斯特菌的各种种群密度为2.2×101至2.2×106cfu/mL的校准图,发现捕获效率为75%。优化程序后,单核细胞增生李斯特菌的种群密度和拉曼信号强度在102至106cfu/mL之间显示出良好的线性相关性(R2=0.991)。提出的夹心测定法提供了低检测限和定量限,为12cfu/mL和37cfu/mL,分别。我们还将实验结果与参考板计数方法进行了比较,并使用牛奶样品证明了所提出的测定法的实用性。
它集中在牛奶样品中单核细胞增生李斯特菌的计数以及通过拟议的SERS方法和平板计数法获得的牛奶分析结果的比较中保持了食物的一致性。在本研究中,对所有参数进行优化,以选择基于SERS的单核细胞增生李斯特菌免疫测定方法,以确保LOD,选择性,精度和可重复性。