Chemiluminescence-triggered fluorophore release: Approach for in vivo fluorescence imaging of hydrogen peroxide

Chemiluminescence (CL) of luminol is a well-established technology for in vitro biochemical analysis of hydrogen peroxide (H2O2). However, applications of chemiluminescence as a signal transduction trigger for fluorophore release still remain to be exploited. In this paper, we rationally design a chemiluminescence-triggered fluorophore release approach for imaging of H2O2 in vivo. The o-benzyl alcohol-decorated block poly (carbonate)s copolymer, viz. PMPC-ONA, was synthesized affording the final formation of the H2O2 responsive micelles, in which luminol, fluorophore, and hemin were wrapped forming L/H/S@PMPC-ONA nanoprobe. The presence of H2O2 diffuses into the nanoparticles and reacts with the hemin, generating high-energy reactive oxygen that could chemically excite the luminol triggering the chemiluminescence for cleaving nitrosobenzaldehyde recognition sites. The process could lead to destabilize the micelles and release the fluorescent indicator for imaging of H2O2. The concentration of H2O2 can be determined from 0.02 to 100 mu M with a detection limit of 0.01 mu M. The feasibility of L/H/S@PMPC-ONA is demonstrated for investigating fluorescence imaging of endogenous H2O2 in cells and mice. As far as we know, this is the first paradigm of rationally designed chemiluminescence as a signal transformation trigger for fluorophore release.