Abstract
A bimetallic electrode composed of copper microparticles dispersed onto a gold surface (Au/Cu) has been investigated as an amperometric sensor using glucose as a model compound. Such a sensing electrode has been prepared by electrochemical deposition of Cu 0 from 50 mM Cu 2+ and subsequent potential cycling in an alkaline medium. The morphology of the copper deposit has been examined by scanning electron microscopy. The effects of copper loading, scan rate, hydroxide concentration, and applied potential on the electrocatalytic oxidation of glucose have been also investigated. Long-term electrode stability, background current, sensitivity, and linear range of the Au/Cu electrode have been assessed for constant-potential amperometric detection (DC) at +0.550 and +0.350 V, and in pulsed-potential amperometric detection (PAD). When used as an amperometric sensor in the DC mode at an applied potential of +0.350 V, the bimetallic electrode yields a detection limit of 0.8 pmol glucose (S/N=3) with a linear dynamic range of four orders of magnitude. Comparable results have been obtained when the bimetallic sensing electrode was used in the DC mode at +0.550 V and in the PAD mode. Good mechanical stability under forced flow hydrodynamic conditions was also found upon changing the detection mode from DC to PAD and vice versa, making the multifunctional amperometric sensor very attractive for analytical applications in flowing streams.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
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.