Abstract
Food poisoning is an obstinate global issue. The rapid detection of pathogens before food intake can be a good strategy to avoid being infected. However, conventional methods usually take more than two days for pathogens incubation and detection. Vancomycin can capture the bacteria using the linkage of five hydrogen bonds between the heptapetide backbone and the D-alanyl-D-alanine dipeptide extending from the cell wall of bacteria. In this study, we develop a rapid bacteria detection device based on the vancomycin modified large graphene oxide (VLGO) transistor. At first, a single-layered graphene was prepared by chemical vapored deposition method3 and transferred onto PET as the substrate. Second, we modified the surface by oxygen plasma treatment. Further, the surface of graphene was functionalized with vancomycin. Finally, the pads of source and drain were deposited onto the VLGO surface. The device is demonstrated to be simple, rapid and reusable bydropping a 10µL solution onto surface of VLGO followed by applying a voltage bias between source/drain. As a p-type transistor, the density of the holes on VLGO surface increases once the bacteria were captured by vancomycin. The detection readout is obtained by comparing the conductance before and after the applying the sample solution onto the VLGO transistor. The results demonstrated that the detection limit is 16 cfu/ml, 11cfu/ml for S.auresus and E.coli, respectively. The response time is 15 minutes. The device is often rapid detecting bacteria and a promising candidate to overcome the hurdles encountered by conventional methods care of food poisoning.