The Effects of Black Phosphorus-Based Composites on Foodborne Pathogen Growth and Biofilm

Foodborne infections are one of the most important problems in the protection of human health. Bacillus cereus and Salmonella enteritidis as the most common foodborne pathogens are the main cause of food poisoning. Due to the inadequacy of traditional antibiotics, biofilm formation and increase in resistant species, the control of the pathogen growth is a quite challenging issue. Recently, Black Phosphorus (BP) nanosheets as a rising star 2D semiconductor, has attracted great attention due to their specific surface interface interactions. Photo-activated BP-based nanocomposites could trigger the release of inorganic nanoparticles, creating superior antibacterial functions. In this work, NIR light-induced antibacterial activities of pristine BP nanosheets, BP/Ag and BP/Au nanocomposites were tested on Bacillus cereus and Salmonella enteritidis and both of BP/Au or BP/Ag exhibited superior growth inhibition efficiencies compared to pristine BP nanosheets due to the active sites for physical contact with bacterial membranes as well as production of ROS. SEM analysis proved that BP-based nanocomposites create physical membrane damages. Antibiofilm activities of the nanocomposites were also examined, which is higher than BP nanosheets alone. Accordingly, due to the sharp edges, NIR-triggered photothermal effect and Schottky interaction of nanocomposites the biofilm structure was mechanically damaged. This work provides an idea to control the growth of bacteria by BP-based nanocomposites, which have the potential to be used in large-scale approaches as an alternative to antibiotics.