An Innovative Route To Prepare The All-solid-state Electrochemiluminescent Electrode

As a conventional electrochemiluminescence(ECL) reagent, luminol has attracted more attention recently due to its promising advantages such as high sensitivity, low detection limit and wide linear range. In this study, we will describe two approaches to develop all-solid-state electrochemiluminescent(ECL) electrodes.In part 1, electrochemical polymerization of luminol /aniline on the Au Ag/Ti O2 nanohybrid functionalized indium tin oxide(ITO) coated glass as working electrode in0.5M H2SO4 solution was successfully carried out. The properties of this solid phase ECL electrode are characterized by cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and scanning electron microscopy(SEM) etc. ECL studies proved that the all-solid-electrode has ECL emission, sensitive response for H2O2 and satisfactory stability. Under optimized conditions, the resulting electrode linearly responded the concentration as a regression equation of I = 97.4 +74.1×C(10-5M)(r=0.994) and a low detection limit of 5.19×10-9M for hydrogen peroxide.Then, we will describe an novel approach to develop an all-solid-state electrochemiluminescent(ECL) electrode for reagentless detection in detail. It was found that poly(luminol/aniline) nanorods could be synthesized in aqueous medium by a simple one-pot strategy with APS as initiator. The properties of the copolymer were characterized by microscopic, electrochemical and spectrometric investigations. It was then immobilized onto the surface of indium tin oxide coated glass to act as a working electrode for ECL analysis with the flow-injection mode. The as-prepared modified electrode exhibited an ECL response in alkaline aqueous solution. Then an ECL sensor toward some oxidants or antioxidants such as H2O2 or resveratrol was developed. The response was linear within the concentration range of H2O2 from 3.0×10-6 to 1×10-4M with a detection limit of 2.3×10-7M(S/N=3). On this basis, the built reagentless ECL-FIA system was successfully applied to evaluate the gross antioxidant activity ofsome fruits with satisfactory results.Compared with previous reports, this is a facile and low-cost approach to prepare the all-solid-state ECL electrode. The results also imply that the mass-production of disposable, inexpensive ECL electrode would become feasible.This ECL electrode makes a possibility of reagentless FIA detection with a single-channel instrument.