posted on 2023-12-01, 16:34authored byXiaoxia Liu, Yong Wang, Yixin Peng, Jinjin Shi, Wenjun Chen, Wei Wang, Xing Ma
Enzyme-catalyzed micro/nanomotors (MNMs) exhibit tremendous
potential
for biological isolation and sensing, because of their biocompatibility,
versatility, and ready access to biofuel. However, flow field generated
by enzyme-catalyzed reactions might significantly hinder performance
of surface-linked functional moieties, e.g., the binding interaction
between MNMs and target cargos. Herein, we develop enzymatic micromotors
with spatially selective distribution of urease to enable the independent
operation of various modules and facilitate the capture and sensing
of exosomes. When urease is modified into the motors' cavity,
the
flow field from enzyme catalysis has little effect on the exterior
surface of the motors. The active motion and encapsulating urease
internally result in enhancement of ∼35% and 18% in binding
efficiency of target cargos, e.g., exosomes as an example here, compared
to their static counterparts and moving micromotors with urease modified
externally, respectively. Once exosomes are trapped, they can be transferred
to a clean environment by the motors for Raman signal detection and/or
identification using the surface Raman enhancement scattering (SERS)
effect of coated gold nanoshell. The biocatalytic micromotors, achieving
spatial separation between driving module and function module, offer
considerable promise for future design of multifunctional MNMs in
biomedicine and diagnostics.