Macromolecules, Vol.53, No.14, 5826-5832, 2020
Chemiluminescent Read-Out of Degradable Fluorescent Polymer Particles
The design of chemiluminescent degradable particles is largely an unexplored field. We, herein, pioneer self-reporting chemiluminescent microspheres, allowing one to readily monitor their degradation. Initially, fluorescent particle formation is induced by cross-linking a photoreactive polymer (poly(styrene-co-tetrazole), 1900 g mol(-1), D = 1.1) and a peroxyoxalate dilinker under irradiation (lambda(max) = 300 nm) employing the nitrile-imine tetrazole-ene cycloaddition (NITEC). Similar to a precipitation polymerization technique, the synthesis does not require any stabilizers, bases, or initiators and proceeds at ambient temperature to yield highly fluorescent microspheres (D-n = 700 nm) in less than 30 min. Next, the particles are degraded on demand by addition of hydrogen peroxide that cleaves the peroxyoxalate linking points and subsequently disintegrates the particles. Degradation of the microspheres can be readily monitored by the light emitted during the peroxyoxalate chemiluminescent reaction process. Importantly, while the present contribution describes the incorporation of degradable CL linkages into polymeric microspheres, the approach can be more broadly implemented in the synthesis of complex macromolecular architectures facilitating optical readout of degradable scaffolds.