Development of a dual-mode Ru-UiO-TPEA MOF probe for highly sensitive and accurate detection of Cu2+ in biological systems

Cu2+ serves as a significant biomarker in various physiological processes. This study presents the development of a novel Ru-UiO-TPEA functionalized metal-organic framework (MOFs) probe for Cu2+ detection, employing both electrochemiluminescence (ECL) and electrochemical (EC) methods. Employing a dual ligand-assisted energy transfer approach, we synthesized Ru-UiO with optimal ECL and EC properties by adjusting the synthesis ratio of biphenyldicarboxylic acid to Ru(dcbpy)32+. This was followed by its conjugation with N-(2-aminoethyl)-N, N′, N′-tris(pyridin-2-ylmethyl) ethane-1,2-diamine (AE-TPEA) to form the highly conjugated Ru-UiO-TPEA probe for Cu2+ detection. As the Cu2+ concentration increased, the probe exhibited a diminished ECL signal and an enhanced differential pulse voltammetry (DPV) signal. The dual-mode detection method enabled cross-validation of the ECL and EC signals, enhancing accuracy and effectively minimizing errors. The ECL and EC methods had detection limits of 0.26 nM (range: 1 nM to 10 μM) and 0.65 nM (range: 2 nM to 80 μM), respectively. Meanwhile, these two methods can effectively detect Cu2+ in rat brain microdialysis fluid. Notably, the measured concentrations correlated well with those determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), highlighting its potential in biological and clinical bioelectronic sensing applications.