Portable and high-throughput electrochemiluminescence detection of catechol based on self-enhanced Au-Ru@Zn MOF with...

A portable, high-throughput visual sensing platform was constructed for the effective detection of catechol (CA), on the basis of the single-electrode electrochemistry system (SEES) and a self-enhanced electrochemiluminescence (SEECL) material, namely Au-Ru@Zn metal-organic framework (MOF). It was found that Ru(bpy)₃²⁺ and oxalate co‑encapsulated within the Ru@Zn MOF generated a SEECL signal. To further amplify the SEECL response, tripropylamine (TPA) was introduced as an exogenous co-reactant, synergizing with endogenous oxalate to establish dual ECL pathways. The oxidation product of CA, semiquinone radicals, is proposed to effectively quenched photoexcited Ru(bpy)₃²⁺* species and competitively consume the precursor Ru(bpy)₃³⁺ by reducing it to Ru(bpy)₃²⁺, thereby causing the ECL signals of Au-Ru@Zn MOF to be significantly quenched. Under optimal experimental conditions, the Au-Ru@Zn MOF-modified SEES exhibited excellent ECL response performance toward CA, with a linear detection range from 1.0 × 10⁻⁹ to 5.0 × 10⁻⁴ mol·L⁻¹ and a detection limit as low as 7.94 × 10⁻¹⁰ mol·L⁻¹ (S/N = 3). Additionally, the proposed SEES successfully detected CA in tea with the recoveries ranging from 98.8% to 101.0%. This work offers a novel approach for the sensitive detection of CA and has significant application possibilities in the realm of food safety monitoring with the benefits of high throughput, portability, and low cost.