KCS

Electrochemical sensors and biosensors based on electrochemiluminescence (ECL) of luminol and tris(2,2’-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺) electrochemiluminescence (ECL) haven developed over the last 10 years in my laboratory. In particular, ECL has attracted much attention as a powerful analytical tool due to its inherent sensitivity, selectivity, and wide linear dynamic range for a variety of analytes such as alkylamines, amino acids, NADH, and a number of pharmaceutical compounds. The ECL emission of the Ru(bpy)₃²⁺/analyte system presumably arises from the energetic electron transfer between the electrogenerated Ru(bpy)₃³⁺ and a strong reducing intermediate (reductant) formed by the oxidation of analytes. The reaction scheme for Ru(bpy)₃²⁺ ECL indicates that the starting material Ru(bpy)₃²⁺ is regenerated in-situ when it is immobilized on an electrode surface. Therefore, much efforts have been focused on the immobilization of Ru(bpy)₃²⁺ on an electrode surface, thus recycling Ru(bpy)₃²⁺ permanently in theory and making the detection system simpler in ECL-based chemical sensors, biosensors, and detectors in flowing streams such as high-performance liquid chromatography, capillary electrophoresis and microchip. In the present seminar, novel approaches for the preparation of the Ru(bpy)₃²⁺ ECL sensor will be presented. Electrochemical and ECL behaviors of the new ECL sensors will be presented along with their possible applications as chemical sensors and biosensors. In addition, electrochemical biosensing of carbohydrate and carbohydrate-binding proteins based on carbohydrate-stabilized gold nanoparticles will be discussed.