A Photochemical Ligation System Enabling Solid‐Phase Chemiluminescence Read‐Out

The peroxyoxalate chemiluminescence (PO-CL) reaction is among the most powerful and versatile techniques for the detection of hydrogen peroxide (H2 O2 ) and has been employed in various biological and chemical applications over the past 50 years. However, its two-component nature (peroxyoxalate and fluorophore) limits its use. This contribution introduces an innovative and versatile photochemical platform technology for the synthesis of inherently fluorescent PO probes by exploiting the nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) reaction. In the presence of hydrogen peroxide, the pioneered "2-in-1" molecule emits either yellow or blue light, depending on tetrazole (Tz) structure. Even in the absence of base, the emitted light remains visible and H2 O2 could be detected in the nanomolar range. Critically, the PO-Tz can be readily incorporated into polymeric materials. As a first application of this promising material, a tailor-made PO-Tz is grafted on poly(divinylbenzene) (PDVB) particles to enable solid-phase chemiluminescence on microspheres.