Solid-state electrochemiluminescence sensor based on the carbon fibers derived from ZIFs-containing electrospun fibers for chlorpyrifos detection

Carbon fiber containing zeolite imidazole framework-67 (ENCF-67) combined with graphene oxide (GO) and ruthenium bipyridine [Ru(bpy)32+] was first applied in the field of electrochemiluminescence (ECL). ENCF-67, GO@Ru(bpy)32+ and Nafion were successively modified on the electrode surface by layer-by-layer assembly method to fabricate a simple and sensitive solid-state ECL sensor. ENCF-67 prepared by electrostatic spinning combined with high temperature pyrolysis can not only fix Ru(bpy)32+, but also shorten the electron transport distance and promote the system electron transport due to the large specific surface area and porous structure. GO, which has a large specific surface area, worked with ENCF-67 to immobilize Ru(bpy)32+ and promote electron transfer in the system. The constructed sensor can obtain a significant ECL phenomenon under neutral condition. Chlorpyrifos can obviously quench the ECL signal of the constructed sensor, and the quenching value was associated with the concentration of chlorpyrifos. From 1.0 x 10-13 M to 1.0 x 10-6 M, the quenching value was positively correlated with the logarithm value of the concentration, which can be used for the quantitative detection of chlorpyrifos residues. This work not only expanded the application range of carbon fibers, but also provided an effective way for ECL signal amplification.