Preparation and Characterization of an Electrogenerated Chemiluminescence Sensor by Electrochemical Grafting of 4-Nitrophenyl Diazonium Salts Onto a Glass Carbon Electrode

摘要

An ECL sensor was fabricated by immobilization of a tris(2,2'-bipyridyl)ruthenium (II) complex (Ru(bpy)_3~(2+)) to an amine group-modified GC electrode (NH_2-GC electrode). Here, the NH_2-GC electrode was prepared by electrochemical reduction of a nitro group-modified GC electrode in 0.1 M KCl ethanol solution under H_2 gas, which was followed by electrochemical grafting of 4-nitrophenyl diazonium salts in 0.1 M NBu_4BF_4 acetonitrile solution onto the GC electrode. The prepared ECL sensor was successfully confirmed via cyclic voltammetry, contact angle, scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and ECL spectrometry. The contact angle for the surface of the GC electrode, NO_2-GC electrode, and NH_2-GC electrod was 88.4°, 67.4°, and 52.4°, respectively. The stability of the ECL sensor was investigated under continuous cyclic potential scanning for 55 cycles and the ECL intensity remained at 55%. The prepared ECL electrode can be expected to immobilize enzymes for preparation of the ECL biosensor to detect target molecules.