RESUMO
We demonstrate a reliable microfabrication process for a combined atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM) measurement tool. Integrated cone-shaped sensors with boron doped diamond (BDD) or gold (Au) electrodes were fabricated from commercially available AFM probes. The sensor formation process is based on mature semiconductor processing techniques, including focused ion beam (FIB) machining, and highly selective reactive ion etching (RIE). The fabrication approach preserves the geometry of the original AFM tips resulting in well reproducible nanoscaled sensors. The feasibility and functionality of the fully featured tips are demonstrated by cyclic voltammetry, showing good agreement between the measured and calculated currents of the cone-shaped AFM-SECM electrodes.
Assuntos
Boro/química , Diamante/química , Técnicas Eletroquímicas/instrumentação , Ouro/química , Microscopia de Força Atômica/instrumentação , Microscopia de Força Atômica/métodos , Nanotecnologia/métodos , Algoritmos , Cromo/química , Técnicas Eletroquímicas/métodos , Eletroquímica , Microeletrodos , Microscopia Eletrônica de Varredura , Microscopia de Varredura por Sonda/instrumentação , Microscopia de Varredura por Sonda/métodos , Silício/química , Compostos de Silício/química , Espectrometria por Raios X , Titânio/químicaRESUMO
The electrochemical oxidation of 2,6-dichloro-1,4-phenylenediamine was studied at a glassy carbon electrode in a 50 vol% methanol-water mixture containing 0.1M HClO(4). Single sweep voltammograms are compared with curves obtained by digital simulation. Characteristic reaction parameters, such as formal potentials, charge transfer coefficients, rate constants of the electrochemical and the chemical steps, and diffusion coefficients, were determined from potential-step experiments in combination with a simulation-curvefitting routine.
