Abstract

Chemically modified electrodes have been studied to obtain new and better electrochemical sensors. Transparent conductive oxides, such as fluorine-doped tin-oxide (FTO), shows electrical conductivity comparable to metals and are potential candidates for new sensors. In this work, FTO was modified by gold electrodeposition from chlorine-auric acid solution using cyclic voltammetry (CV) technique. A set of different materials were produced, varying the scan number. Scanning electron microscopy and electrochemical impedance spectroscopy were performed for the characterization of electrodes surfaces. From this analysis was possible to observe the resistive, capacitive and difusional aspects from all kind of modified electrodes produced, establishing a relationship between this parameters and the scan number. The electrode with 100 scans of CV presented better characteristics for an electrochemical sensor; it has the lowest global impedance and rising of capacitive behavior (related to electrical double layer formation) at lower frequencies. This electrode was tested for paracetamol and caffeine detection. The results showed a high specificity, decreased oxidation potential (0.58 V and 0.97 Vvs. SCE, for paracetamol and caffeine, respectively) and low detection limits (0.82 and 0.052 µmol L-1).

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.