Analyte-templated aggregate remodeling for broad-spectrum visual screening of synthetic cannabinoids

Synthetic cannabinoids (SCs) are a rapidly evolving class of new psychoactive substances whose structural diversity continues to challenge field-deployable screening. Here we report an aggregate-remodeling sensing strategy based on an AIE-active coumarin-naphthalimide dyad (NAP-CMR) that converts the shared hydrophobic, aromatic-rich attributes of chemically diverse SCs into a high-contrast optical readout. In aqueous methanol (CH₃OH) mixtures, NAP-CMR forms weakly emissive, aggregate-associated states featuring a broad, red-shifted emission band. Upon exposure to SCs, the analytes act as structural templates to reorganize these aggregates and restore a more radiative ICT-like emissive manifold, producing a rapid low-radiance-to-bright transition with a clear yellowish-green-to-cyan color change. Using ethyl (1-(4-fluorobenzyl)-1H-indazole-3-carbonyl)valinate (EMB-FUBINACA) as a representative target, the assay responds within <1 s and affords a detection limit of 33.2 μM, while maintaining consistent broad-spectrum recognition across 21 additional SC variants. Minimal interference is observed from common drugs of abuse, new psychoactive substances, and SC precursors. As a proof-of-concept quantitative validation, ethyl 3,3-dimethyl-2-(1-pentyl-1H-indazole-3-carboxamido)butanoate (EDMB-PINACA) was further quantified in a representative chocolate matrix using a solid-phase spiking protocol, giving recoveries of 92.9%-96.5%. This work highlights analyte-templated remodeling of metastable aggregates as an attribute-based route toward optical screening for forensic and public-health applications.