<p>Lead halide perovskites (LHP) microcrystals are promising materials
for various optoelectronic applications. Surface coating on particles is a
common strategy to improve their functionality and environmental stability, but
LHP is not amenable to most coating chemistries because of its intrinsic
weakness against polar solvents. Here, we describe a novel method of synthesizing
LHP microcrystals in a super-saturated polar solvent using sonochemistry and
applying various functional coatings on individual microcrystals <i>in situ</i>.
We synthesize cesium lead bromine perovskite (CsPbBr<sub>3</sub>)
microparticles capped with organic poly-norepinephrine (pNE) layers. The
catechol group of pNE coordinates to bromine-deficient lead atoms, forming a
defect-passivating and diffusion-blocking shell. The pNE layer enhances the stability
of CsPbBr<sub>3</sub> in water by 2,000-folds, enabling bright luminescence and
lasing from single microcrystals in water. Furthermore, the pNE shell permits
biofunctionalization with proteins, small molecules, and lipid bilayers. Luminescence
from CsPbBr<sub>3</sub> microcrystals is sustained in water over 1 hour and
observed in live cells. The functionalization method may enable new applications
of LHP particles in water-rich environments.<b></b></p>
Methacrylate Polymer Scaffolding Enhances the Stability of Suspended Lipid Bilayers for Ion Channel Recordings and Biosensor Development
