Electroactive Metal–Organic Frameworks as Emitters for Self‐Enhanced Electrochemiluminescence in Aqueous Medium

Abstract

Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E‐MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E‐MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E‐MOFs demonstrate excellent performance with surface state model in both co‐reactant and annihilation ECL in aqueous medium. Compared with the individual components, E‐MOFs significantly improve the ECL emission due to the framework structure. The self‐enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre‐reduction electrolysis. The self‐enhanced mechanism is theoretically identified by DFT. The mixed‐ligand E‐MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies.

Lewis‐Pairing‐Induced Electrochemiluminescence Enhancement from Electron Donor‐Acceptor Diads Decorated with Tris(pentafluorophenyl)borane as an Electrochemical Protector

“…By applying a potential of −2.40 V vs. Ag/AgCl for 2.0 s, ECL was successfully generated from the modified electrode, 1 p ‐TPFB/GCE, in the presence of excess K 2 S 2 O 8 (Figure 6c). ECL emission was not detected in the absence of K 2 S 2 O 8 , while a weak emission was observed at approximately 700 nm at −2.00 V (Figure S25a), which was an artifact related to the decomposition of K 2 S 2 O 8 [22b] . The energy of the film ECL peak maximum (560 nm) was 1940 cm −1 lower than that of the solution ECL peak maximum (505 nm).…”

Electrochemiluminescence Distance and Reactivity of Coreactants Determine the Sensitivity of Bead‐Based Immunoassays

“…In this Scheme, highly efficient luminophores and coreactants are equally important in promoting the analytical sensitivity of ECL immunoassays. A large number of luminophores have been developed in past two decades, including metal nanoclusters, [23–26] quantum dots, [27–29] metal organic frameworks, [30, 31] metal complexes [32–34] and dye doped nanoparticles, [35, 36] some of which are very promising to be used as the substitute for Ru(bpy) 3 2+ to increase the analytical sensitivity. On the other hand, as for the LOP route in bead‐based ECL immunoassays, an ideal coreactant should be highly reactive and meanwhile the intermediate radical cation should have a long lifetime.…”

Highly Efficient Wavelength-Resolved Electrochemiluminescence of Carbon Nitride Films for Ultrasensitive Multiplex MicroRNA Detection

“…To date, several strategies have been employed to amplify ECL signals, including self-enhancement, ,− radical stabilization, , aggregation-induced ECL, , pre-oxidation, and host–guest recognition . Despite these unprecedented successes, the study of ECL luminophores with strong ECL emission and the associated mechanism is still at the initial stage.…”