Electrochemiluminescent quenching of luminol–doped Zr–MOFs for ATP detection through scavenging ROS using gallic acid–capped Au nanoparticles

In the present study, the highly efficient electrochemiluminescence (ECL) luminophores of Zr-based metal–organic frameworks (MOFs) coordinating with the amino group of luminol (Zr–Lu–MOFs) were developed for fabricating a sensing platform. The ECL emission of a Zr–Lu–MOF/H2O2 system with strong and stable ECL signals was triggered through cyclic voltammetry. Adenosine triphosphate (ATP) was firmly assembled on Zr–Lu–MOF because of the high affinity of Zr4+ toward phosphate groups. ATP was detected using gallic acid (GA)-capped Au (GA@Au) nanoparticles combined with an ATP aptamer. The GA@Au nanoparticles quenched the ECL behavior of the luminol/H2O2 system, and the quenching mechanism was ascribed to the GA scavenging superoxide radical (O2•−) that was generated via the electron redox reaction in H2O2. Under optimal experiments, an ECL biosensor with a linear range of 0.100–1000 nM and a detection limit of 0.0353 nM (S/N = 3) was designed for the selective and sensitive detection of ATP. Thus, the proposed ECL biosensor exhibited good performance with high stability and acceptable fabrication reproducibility, providing a valuable strategy for clinical diagnostics and therapeutics.