The COVID-19 pandemic has shed light on the need for antimicrobial surfaces that down regulate the transmission of pathogens through touching commonly encountered surfaces such as handrails and door handles, without requiring external activation or chemicals for sanitation. In this work, at the intersection of Materials Science and Bioengineering, the biocidal capabilities of cuprous oxide (Cu2O, cuprite) powder were evaluated by obtaining fundamental correlations between induced lattice defects and enhancement of biocidal activity.
Antimicrobial coatings made from these processed powders demonstrated a passive “contact-kill” response to E. coli bacteria that was 4x (400%) faster than coatings made from unprocessed powder, shown in Figure 1. Greater than a 99% bacterial reduction was achieved within 30 minutes of exposure. The upregulated antibacterial response of the processed powders is positively correlated with extensive induced crystallographic disorder and microstrain in the Cu2O lattice accompanied by color changes that are consistent with an increased semiconducting bandgap energy. Increasing the relative proportion of lattice-defective cuprous oxide exposed to the environment at the coating surface is anticipated to further enhance the antipathogenic capability of this abundant, inexpensive, robust, and easily handled material for wider application in contact-kill surfaces.
