Zn-BBPY-metal-organic gel electrochemiluminescence for cytochrome c detection

Zn–BBPY–MOG was synthesized via simple ambient self-assembly. • Zn–BBPY–MOG served as a self-luminescent ECL platform. • Zn–BBPY–MOG/S₂O₈ 2− achieved 81.5% relative ECL efficiency. • Cyt c was detected with a low LOD of 0.025 nM. Electrochemiluminescence (ECL) sensing has emerged as a powerful analytical technique for biomolecule detection. Cytochrome c (Cyt c), an important biomarker associated with cellular damage and various diseases, has attracted considerable attention in bioanalytical research. Herein, we report a zinc-based metal-organic gel (Zn-BBPY-MOG) as a self-luminescent ECL platform for the sensitive detection of Cyt c. Zn-BBPY-MOG was synthesized under ambient conditions via coordination between Zn 2+ ions and the π-conjugated ligand 2,6-bis(2-benzimidazolyl)pyridine (BBPY). The resulting gel network, featuring strong coordination interactions and an extended π-conjugation, facilitates efficient electron transfer and enables intense ECL emission in the presence of S₂O₈ 2− as a coreactant. Compared with the standard Ru(bpy)₃ 2+ /S₂O₈ 2− reference system, Zn-BBPY-MOG/S₂O₈ 2− achieved a relative ECL efficiency of 81.5%, demonstrating its efficient ECL performance. Based on the quenching effect of Cyt c on the Zn-BBPY-MOG/S₂O₈ 2− ECL system, a sensitive and quantitative detection strategy was established. The developed sensing platform exhibited a wide linear detection range from 1 to 1000 nM and an ultralow detection limit of 0.025 nM for Cyt c. Moreover, the proposed method was successfully applied to the determination of Cyt c in serum samples, achieving satisfactory recoveries ranging from 99.20% to 102.50%. These results demonstrate the reliability and practical applicability of the Zn-BBPY-MOG-based ECL platform for sensitive biomolecular analysis. Download: Download high-res image (87KB) Download: Download full-size image