Ultrabright chemiluminescent scaffold for portable visualizing organophosphorus compounds

Chemiluminescence (CL) has been recognized as one of the most powerful tools in analytical assays with high signal-to-noise ratio. Ultrabright chemiluminophores are highly desired in CL-based analytical approaches, imaging, for example, although the design of CL scaffold with ultra-brightness remains a challenge. We report a feasible strategy for constructing an ultrabright chemiluminophore, BTCL-Cl, by grafting benzothiazole moiety to the dioxetane center of Schaap's adamantylidene-dioxetane. Compared with the classical undecorated chemiluminophores, the CL quantum yield of BTCL-Cl has improved by 2.4-folds to 17.6% with a short half-life due to deprotonation under alkaline conditions. Probe CL-HMPC, the thiol-recognizer-decorated BTCL-Cl, has demonstrated ultrahigh sensitivity (detection limit is 6.0 ng/mL) in monitoring organophosphorus compounds (OPs) by immediate releasing of thiols after the alkaline hydrolysis of OPs. The OPs-triggered remarkable CL enhancement has ensured quantitively visualization of OPs in the naked eye by imaging with a smartphone in situ. Using the versatile and ultrasensitive CL platform, we succeeded in feasibly visualizing the concentration of OPs on cabbage leaves on farmland by portable setups. The simple and promising approach for analyzing pesticides and potentially other targets brings tremendous imagination in related areas.