A novel “off-on” electrochemiluminescence sensor based on highly efficient resonance energy transfer in C-g-C3N4/CuO nanocomposite

A signal “off-on” electrochemiluminescence resonance energy transfer (ECL-RET) sensor based on carboxylated graphene-like carbon nitride (C-g-C3N4) as donor and CuO nanoneedles as acceptor has been constructed. The distance between donor and acceptor is a critical factor for ECL-RET sensors. Herein, we used a new method to make CuO nanoneedles grow in situ on C-g-C3N4 to form a nanocomposite, largely reducing the distance between donor and acceptor and greatly improving ECL-RET efficiency. In this system, because the CuO could be reduced by dopamine (DA), the ECL emission was significantly enhanced. Hence, a sensitive ECL sensor was successfully fabricated for quantitative detection of DA in dopamine hydrochloride injection and human serum sample. Further, the ECL-RET sensor exhibited a wide linear range from 10 nM to 1 mM, as well as a low detection limit of 8.2 nM. With its excellent stability and selectivity, the novel strategy will enable numerous applications in biological systems.