Here, we proposed a novel solution for reversible regulation
of
the reactive oxygen species (ROS) level using a semiconductor heterojunction.
Two metal-based ROS scavengers containing n-type CeO2 nanoparticles
and n-type Cu-doped diatom biosilica (Cu-DBs) were integrated by a
hydrothermal method to form a typical n–n semiconductor heterojunction
(Ce/Cu-DBs). Unlike the control of the ROS level by a single ROS scavenger
or ROS-generating agent, Ce/Cu-DBs could quickly eliminate ROS by
cascade catalytic reaction, which readily switched to ROS generation
through a near-infrared (NIR)-triggered photocatalytic effect. This
NIR mediated ROS regulation system provided a noninvasive strategy
for reversible control of the ROS level in vitro and in vivo. The Ce/Cu-DBs could relieve cellular oxidative
stress by clearing local excessive ROS while inhibiting bacterial
growth by increasing ROS levels under NIR radiation. Benefiting from
the reversible regulatory effect of Ce/Cu-DBs, programmable healing
of infected wounds was realized via on-demand anti-infection and inflammation
reduction. This work provided a general method with highly spatiotemporal
resolution to a remote and sustainable control ROS level, which had
great potential for the biomedical field and regulation of chemical
reactions.