Real-Time Pathogen Determination by Optical Biosensing Based on Graphene Oxide

Pathogenic bacterial contamination in food is a public health concern. It represents a health and safety consumer risk that could cause several diseases and even death. Currently, the food industry uses culture-based assays to determine the presence of pathogens as a gold standard method. Although this method is highly accurate, it is often time-consuming and expensive. In this regard, the development of biosensing platforms results as an alternative for the reduction of time and cost of pathogenic bacteria detection in food. In this work, we report the development of a single-step bacterial detection platform based on graphene oxide. Non-radiative energy transfer between graphene oxide coated microplates (GOMs) and photoluminescence bioprobes (PLBs) is presented in absence of the target analyte, but in presence of analyte, PLBs exhibit strong photoluminescence due to the distance between GOMs and PLBs. These PLBs are based on quantum dot (Qds)-antibody (Ab) complexes, thereby resulting as a biorecognition and interrogation element. Escherichia coli was used as model analyte. In optimal conditions, the bacterial detection platform reached a limit of detection around 2 CFU mL−1 in 30 min, enabling a fast and sensitive alternative for bacterial detection. The biosensing platform was also used to test food industry samples achieving a qualitative response, that allows determining the presence of E. coli during the first 30 min of the assay. This biosensing strategy potentially offers a low-cost and quick option for the food industry to assure the quality of the product and consumer safety.