posted on 2023-02-17, 16:34authored byYanwei Lu, Xuedong Huang, Shurong Wang, Binxiao Li, Baohong Liu
Direct imaging of electrochemical reactions at the single-molecule
level is of potential interest in materials, diagnostic, and catalysis
applications. Electrochemiluminescence (ECL) offers the opportunity
to convert redox events into photons. However, it is challenging to
capture single photons emitted from a single-molecule ECL reaction
at a specific location, thus limiting high-quality imaging applications.
We developed the nanoreactors based on Ru(bpy)32+-doped nanoporous zeolite nanoparticles (Ru@zeolite) for direct visualization
of nanoconfinement-enhanced ECL reactions. Each nanoreactor not only
acts as a matrix to host Ru(bpy)32+ molecules
but also provides a nanoconfined environment for the collision reactions
of Ru(bpy)32+ and co-reactant radicals to realize
efficient in situ ECL reactions. The nanoscale confinement
resulted in enhanced ECL. Using such nanoreactors as ECL probes, a
dual-signal sensing protocol for visual tracking of a single biomolecule
was performed. High-resolution imaging of single membrane proteins
on heterogeneous cells was effectively addressed with near-zero backgrounds.
This could provide a more sensitive tool for imaging individual biomolecules
and significantly advance ECL imaging in biological applications.