Paper-Based Bipolar Electrode Electrochemiluminescence\nPlatform Combined with Pencil-Drawing Trace for the Detection of M.SssI\nMethyltransferase

Abstract

Herein,\na hand-drawing paper-based bipolar electrode (BPE) electrochemiluminescence\n(ECL) platform for M.SssI methyltransferase (M.SssI MTase) assay was\nproposed via employing high electrocatalytic Pt@CeO₂ as\nan ECL co-reaction accelerator and pencil-drawing graphite electric\ncircuits as wires and electrodes. Notably, the introduction of pencil-drawing\ntrace not only simplified the manufacturing process but also reduced\nthe cost and saved fabricating time. Meanwhile, Pt@CeO₂ with good electrocatalytic activity and satisfactory chemical stability\nwas used at the anode of the closed BPE-ECL device to accelerate the\noxidation rate of uric acid. Due to the balanced charges of the bipolar\nelectrode, the ECL response of the MnS: CdS@ZnS/S₂O₈^2– system emitted on the cathode was enhanced.\nIn situ growth of gold nanoparticles in the two electrode areas was\nconvenient for DNA immobilization. With the above points in mind,\nthe specific DNA double strands functionalized via Pt@CeO₂ were employed to identify M.SssI MTase. The unmethylated DNA double\nstrands were cut by <i>Hpa</i>II endonuclease, resulting\nin the quenching of the ECL signal. Under the optimal conditions,\nsensitive detection of M.SssI MTase in a wide linear range of 0.01–100\nU·mL^–1 with a satisfactory detection limit\nof 0.008 U·mL^–1 was realized. The reliable\nand versatile BPE-ECL tool for the determination of M.SssI MTase with\neasy-to-operate pencil-drawing traces and independent solution systems\nprovides a new opportunity to develop paper-based devices applied\nin early disease diagnosis and pathogenesis research.