Newly designed nanocrystals can kill bacteria under visible light

Newly developed halide perovskite nanocrystals (HPNCs) show potential as antimicrobial agents that are stable, effective and easy to produce.

After almost three years, Rice University scientist Yifan Zhu and colleagues have developed a new HPNC that is effective at killing bacteria in a biofluid under visible light without experiencing light- and moisture-driven degradation common in HPNCs.

A new method using two layers of silicon dioxide that Zhu and colleagues developed over years of work was used in experiments with lead-based and bismuth-based HPNCs to test their antimicrobial efficacy and stability in water. The study is published in Nano Letters.

Researchers tested the antimicrobial properties and durability of their new double-coated HPNCs. They selected lead and bismuth because HPNCs made with both metals are highly effective under visible light and produce singlet oxygen rather than hydroxide, which can be harmful to other organisms.

Zhu and colleagues found that both HPNC varieties showed little to no antimicrobial properties without light. However, under relatively low levels of visible light, both HPNCs destroyed more than 90% of the E. coli bacteria in the solution after six hours. Additionally, both HPNCs showed very little degradation over the four-day test period.

Image source: Nanomaterials, Nanomechanics and Nanodevices Lab/Rice University.