Highly Efficient Intramolecular Electrochemiluminescence Energy Transfer for Ultrasensitive Bioanalysis of Aflatoxin M1

The intermolecular electrochemiluminescence resonance energy transfer (ECL-RET) between luminol and Ru(bpy) 3(2+) was studied extensively to achieve the sensitive bioanalysis owing to the perfect spectral overlap of the donor and acceptor, but it still suffers from the challenging issue of low energy- transfer efficiency. The intramolecular ECL-RET towards the novel ECL compound containing the donor of luminol and the acceptor of Ru(bpy)(2)(mcpbpy)(2+)(Lum-Ru) was designed and investigated. With the high-efficient ECL-RET in one molecule, the highly intense ECL signal of Lum- Ru was obtained owing to the short path of energy transmission and less energy loss between luminol and Ru(bpy)(2)(mcpbpy)(2+). Lum-Ru was further applied to construct a signal- off electrochemiluminescence (ECL) aptasensor for ultrasensitive detection of a harsh carcinogen of Aflatoxin M1 (AFM1). This sensing platform also provides a significant boost for the trace detection of other biomolecules in clinical analysis.