With the widespread use of
antibiotics, the number of severe
infections caused by unknown pathogens is increasing and novel
antibacterial agents with high antibacterial efficiency and selective bacterial killing are urgently needed. In this work, we developed a new kind of functional material based on
silver nanoparticles (AgNPs), whose surfaces were functionalized with
phenylboronic acid (AgNPs-PBAn). The
phenylboronic acid groups on the surface of AgNPs-PBAn could form covalent bonds with the cis-diol groups of
lipopolysaccharide or teichoic
acid on the bacterial surface, which highly promoted the interaction between AgNPs-PBAn and bacteria, resulting in a very strong enhancement of their antibacterial action via membrane disruption. The scanning electron microscopy images revealed that the accumulation of
phenylboronic acid-functionalized AgNPs on the bacterial surface is much more than that of the nonfunctionalized AgNPs. Importantly, the antibacterial efficiency of the
phenylboronic acid-functionalized AgNPs on a series of bacteria is 32 times higher than that of bare AgNPs. Moreover, AgNPs-PBAn showed a high selectivity toward bacteria with an IC50 (half maximal inhibitory concentration to mammalian cells) more than 160 times its MBC (minimum bactericidal concentration). In a model of an E. coli-infected
wound in vivo, AgNPs-PBAn could effectively kill the bacteria with an accelerated wound healing rate. This study demonstrates that
phenylboronic acid surface functionalization is an efficient way to drastically promote the antibacterial activity of AgNPs, improving the selectivity of
silver-based nanoparticles against a variety of bacteria.