Chemiluminescence resonance energy transfer: From mechanisms to analytical applications

Chemiluminescence resonance energy transfer (CRET) is a non-radiative transfer of energy from chemiluminescence (CL) reagent to energy acceptor during the CL reaction. The reaction process does not require excitation from external source, so CRET-based assays have low background and high sensitivity. Recently, efficient energy transfer systems have been proposed and a variety of nanomaterials with different functions have been presented as acceptors. Among them, the "signal-on" type acceptors (e.g., fluorescence dye, quantum dot and semiconducting polymer) can increase the CL intensity effectively, while the "signal-off" type acceptors (e.g., gold nanoparticle and carbon nanomaterials) have highly quenching efficiency. The development of acceptors has extended the applications of CRET ranging from biosensing and bioimaging to biomedicine and therapy. In this review, the CRET modes are divided according to the type of acceptors based on the energy transfer mechanisms. Their recent advances and future prospects are summarized and discussed.