Gold Nanoflower-Enhanced Dynamic Light Scattering Immunosensor for the Ultrasensitive No-Wash Detection of Escherichia coli O157:H7 in Milk
Gold Nanoflower-Enhanced Dynamic Light Scattering Immunosensor for the Ultrasensitive No-Wash Detection of Escherichia coli O157:H7 in Milk
复制标题
金纳米花增强型动态光散射免疫传感器用于牛奶中大肠杆菌 O157:H7 的超灵敏免清洗检测
DOI：
10.1021/acs.jafc.9b03400
复制
发表时间：
2019
影响因子：
6.1
通讯作者：
Xiong Yonghua
中科院分区：
文献类型：
--
作者：
Zhan Shengnan;Fang Hao;Fu Jinmei;Lai Weihua;Leng Yuankui;Huang Xiaolin;Xiong Yonghua
金纳米花（GNF）比相同直径的金纳米球（GNS）表现出更强的光散射能力，从而有助于提高基于散射的传感方法的灵敏度。然而，GNF在基于动态光散射（DLS）的生物传感器中的应用还未见报道。本文首次报道了一种基于动态光散射的免清洗免疫传感器，用于大肠杆菌O 157：H7（E. colio 157：H7）在牛奶中使用GNF进行敏感的信号转导。为了实现这一目标，引入硫醇化的两亲性羧基配体来修饰GNF表面并改善溶液稳定性和抗体功能化。系统地研究了影响GNF_DLS免疫传感器检测灵敏度的几个关键因素。在最佳条件下，GNF_DLS免疫传感器对大肠杆菌具有良好的线性检测. colio 157：H7的检测范围为6 × 100 ~ 6 × 104 CFU/mL，检出限为2.7CFU/mL。结合我们先前报道的两步大体积免疫磁性分离（IMS）方法，所设计的GNF_DLS免疫传感器可以灵敏、选择性和准确地检测E.大肠杆菌157：H7。我们的GNF_DLS方法用于监测1 mL样品溶液中单个细菌细胞的存在的潜力也得到了证明。总体而言，所开发的GNF_DLS免疫传感器可用于快速和高灵敏度的检测病原菌，并可扩展为其他痕量分析物的超灵敏免清洗检测。
Gold nanoflowers (GNFs) exhibit stronger light scattering ability than gold nanospheres (GNSs) with the same diameter, thereby contributing to enhancing the sensitivity of the scattering-based sensing method. However, the application of GNFs in biosensors based on dynamic light scattering (DLS) has not been yet reported. Herein, we describe for the first time an improved no-wash immunosensor based on dynamic light scattering for the detection ofEscherichia coliO157:H7 (E. coliO157:H7) in milk using GNFs for sensitive signal transduction. To achieve this goal, a thiolated amphiphilic carboxyl ligand was introduced to modify the GNF surface and improve solution stability and antibody functionalization. Several key factors that affect the detection sensitivity of our developed GNF_DLS immunosensor were systematically investigated. Under the optimal conditions, our proposed GNF_DLS immunosensor provided an excellent linear detection forE. coliO157:H7 within the range from 6 × 100to 6 × 104colony-forming units (CFU)/mL, with a limit of detection of 2.7 CFU/mL. Combined with our previously reported two-step large-volume immunomagnetic separation (IMS) method, the designed GNF_DLS immunosensor can sensitively, selectively, and accurately detect the presence ofE. coliO157:H7 in pasteurized milk. The potential of our GNF_DLS method for monitoring the presence of a single bacterial cell in 1 mL of sample solution was also demonstrated. Overall, the developed GNF_DLS immunosensor can be used for the rapid and high-sensitivity determination of pathogenic bacteria and can be extended for the ultrasensitive no-wash detection of other trace analytes.