Indirect amperometric detection of non-redox ions using a ferrocene-functionalized and oriented mesoporous silica thin film electrode

Abstract : Vertically oriented and ferrocene functionalized mesoporous silica thin films have been prepared by combining the electrochemically assisted self-assembly (EASA) method with click chemistry. The resulting films are electroactive, involving an electron hopping mechanism between adjacent ferrocene moieties. The electrochemical oxidation of ferrocene into ferricinium ion generates positive charges that are compensated by the ingress of anions into the film, opening the door to possible indirect amperometric detection of non-electroactive anions by flow injection analysis. Operating in an electrolyte-free flow, each injection of an anion (e.g., NO3−) at an electrode biased at a suitable positive potential (i.e., +0.5 V) gave rise to an amperometric response proportional to the anion concentration. However, to avoid the decrease of the electrochemical signal due to the progressive consumption of ferrocene in multiple successive analyses, it was necessary to regenerate the electrode by reduction of ferricinium moieties, which can be achieved in-situ by square wave amperometry. The feasibility to apply such indirect amperometric detection scheme in suppressed ion chromatography (for detecting anions in mixture) was also demonstrated.
Document type :
Journal articles
Complete list of metadatas

https://hal.univ-lorraine.fr/hal-01941813
Contributor : Alain Walcarius <>
Submitted on : Sunday, December 2, 2018 - 2:50:16 PM
Last modification on : Tuesday, December 4, 2018 - 10:05:15 AM

Identifiers

Collections

Citation

Cheryl Karman, Neus Vilà, Christelle Despas, Alain Walcarius. Indirect amperometric detection of non-redox ions using a ferrocene-functionalized and oriented mesoporous silica thin film electrode. Electrochimica Acta, Elsevier, 2017, 228, pp.659-666. ⟨10.1016/j.electacta.2017.01.126⟩. ⟨hal-01941813⟩

Share

Metrics

Record views

31