Department of Biological and Agricultural Engineering, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
Department of Agricultural and Biosystems Engineering, South Dakota State University, Brookings, SD 57007, USA.
Biosensors (Basel). 2022 Oct 21;12(10):908. doi: 10.3390/bios12100908.
O157:H7, one of the major foodborne pathogens, can cause a significant threat to the safety of foods. The aim of this research is to develop an activated biochar-based immunosensor that can rapidly detect O157:H7 cells without incubation in pure culture. Biochar was developed from corn stalks using proprietary reactors and then activated using steam-activation treatment. The developed activated biochar presented an enhanced surface area of 830.78 m/g. To develop the biosensor, the gold electrode of the sensor was first coated with activated biochar and then functionalized with streptavidin as a linker and further immobilized with biotin-labeled anti- polyclonal antibodies (pAbs). The optimum concentration of activated biochar for sensor development was determined to be 20 mg/mL. Binding of anti- pAbs with O157:H7 resulted in a significant increase in impedance amplitude from 3.5 to 8.5 kΩ when compared to an only activated biochar-coated electrode. The developed immunosensor was able to detect O157:H7 cells with a limit of detection of 4 log CFU/mL without incubation. Successful binding of O157:H7 onto an activated biochar-based immunosensor was observed on the microelectrode surface in scanning electron microscopy (SEM) images.
O157:H7 是主要食源性病原体之一，对食品安全构成重大威胁。本研究旨在开发一种无需在纯培养物中孵育即可快速检测 O157:H7 细胞的基于活化生物炭的免疫传感器。生物炭是使用专利反应器从玉米秸秆中开发的，然后使用蒸汽活化处理进行活化。开发的活化生物炭的表面积增加到 830.78 m²/g。为了开发该生物传感器，首先将传感器的金电极涂覆有活化生物炭，然后用链霉亲和素作为连接体进行功能化，并进一步固定生物素标记的多克隆抗体 (pAb)。确定用于传感器开发的最佳活化生物炭浓度为 20 mg/mL。与仅涂覆有活化生物炭的电极相比，抗 pAb 与 O157:H7 的结合导致阻抗幅度从 3.5 增加到 8.5 kΩ。所开发的免疫传感器无需孵育即可检测到 4 log CFU/mL 的 O157:H7 细胞。在扫描电子显微镜 (SEM) 图像中可以观察到 O157:H7 在基于活化生物炭的免疫传感器上成功结合。
