A novel starch-based ethanol gel with contact-killing bacteria to cut off contact transmission of bacteria

Abstract

The large-scale spraying of disinfectants has little effect on cutting off the contact transmission of bacteria, triggering a series of economic burdens and environmental pollution in public places. Herein, a novel multiscale starch-based ethanol gel (MSE) was prepared by shearing cassava starch at different temperatures and subsequently esterifying with oxalic acid to obtain multiscale pyranose esters (MPE), which targeted ethanol in a specific location to release only when human touched. Strong hydrogen bonding and nanoscale voids made MSE locking ethanol, and the destruction of this hydrogen bonding by water and pressure also promoted ethanol release to fingers. In terms of this, fingers could be sterilized by pressing MSE, especially when the pressure force on MSE was greater than 2.263 N, more than 95.76% of E. coli and S. aureus on fingers are inactivated. Meanwhile, compared with pure ethanol disinfectants and commercial ethanol gel, MSE reduced the ethanol dosage by 571 times and 225 times when kept sterile for three days in the same public area. Excellent adhesion and biocompatibility of MSE indicate that novel ethanol gel can be exerted to suppress contact transmission of bacteria in a practical and harmless way.