Antibacterial applications of elemental nanomaterials

The emergence and spread of antimicrobial resistance call for the development of antibacterial substances that may be able to circumvent the resistance mechanisms of bacteria. To this end, intensive research efforts have been directed toward non-antibiotic materials with antibacterial potency. In particular, single-element inorganic nanomaterials have demonstrated promising activity against bacteria, and prominent examples of single-element inorganic nanomaterials include silver (Ag) nanoparticles, 0-, 1- and 2-dimensional carbon nanomaterials, and 2dimensional black phosphorous (BP) nanosheets. With activity modes distinct from those of commercial antibiotics, these single-element inorganic nanomaterials have demonstrated activity against antibiotic-resistant bacterial strains and may delay the emergence of resistance in bacteria. In this review, we focus on silver (Ag) nanoparticles, 0-, 1- and 2-dimensional carbon nanomaterials, and 2-dimensional black phosphorous (BP) nanosheets, and discuss their antibacterial potency, factors that influence their antibacterial performances, as well as their cytotoxicity to mammalian cells.