A ruthenium-nickel metal–organic framework incorporating 2,2'-bipyridine- 5,5'-dicarboxylic acid for dual-mode electrochemiluminescence-fluorescence detection of ferric ions

A novel, low-toxicity Ru-Ni-BPY metal–organic framework (MOF) nanomaterial was developed and a simple and sensitive dual-mode "on–off" ferric ions (Fe 3+ ) sensing platform based on this material constructed. The dual-mode detection method enabled cross-validation of the electrochemiluminescence (ECL) and fluorescent (FL) signals, enhancing accuracy and effectively minimizing errors. In linear ranges of 0.005–10 μM and 0.078–10 μM, Fe 3+ can dramatically quench the ECL and FL signals of the Ru-Ni-BPY MOF, with quenching rates of 91.42% and 91.31%, respectively, and detection limits of 0.1 nM and 9.3 nM, respectively. This ECL method not only achieved efficient detection of Fe 3+ in rat brain microdialysis fluid but also successfully enabled real-time FL detection of Fe 3+ in nude mice. Therefore, this platform has great potential for applications in environmental protection, life sciences, and early disease diagnosis. Graphical abstract