Compartmentalized Amplification and Spectral Engineering of Luminol Chemiluminescence via Host-Guest Cavity Binding...

Luminol chemiluminescence (CL) is widely used in bioanalysis and forensics, yet stringent alkalinity, flash-type kinetics, and blue emission strongly hinder in vivo applications. Here, we report QC4A-8C, a single compartmentalized supramolecular platform that simultaneously addresses these limitations. QC4A-8C is an amphiphilic quaternary ammonium calix[4]arene with orthogonally functionalized upper and lower rims. The cationic cavity selectively encapsulates luminol, induces a pKa shift, and converts luminol into a glow-type emitter at near-physiological pH. In parallel, the hydrophobic lower rim self-assembles into nanoaggregates that compartmentalize fluorescent acceptors (DTBT, MCCH, DCI) in nanometer proximity, enabling sequential chemiluminescence resonance energy transfer (CRET) with high efficiency and red-shifted emission (650-700 nm). As a result, tissue penetration and emission lifetime are substantially extended, and in a lipopolysaccharide-induced peritonitis model, QC4A-8C delivers pronounced signal enhancement over free luminol. This work validates macrocyclic host-guest chemistry as a programmable route to integrate CL amplification with optical spectral engineering for diagnostic imaging.