An Electrochemical Nitrite Sensor Based on a Multilayer Film of Polyoxometalate

Abstract

<span>In this work, we have developed an electrochemical sensor for nitrite detection, based on a polyoxometalate (POM) namely mono-lacunary keggin anion [SiW₁₁O₃₉]^8﹣ cited as (SiW₁₁). Electrochemical characterization of SiW₁₁ shows two-step reduction processes, with formal potentials of ﹣0.5 V (I) and ﹣0.68 V (II). Oppositely charged polyelectrolyte (poly (allylamine hydrochloride) (PAH)) and (SiW₁₁) were assembled alternately to modify glassy carbon electrode. The electrochemical behavior of the modified electrode was studied in detail using cyclic voltammetry (CV). The results showed that SiW₁₁/PAH/GC electrode present good electrocatalytic activity for the reduction of nitrite. The sensor showed a dynamic range from 100 μM to 3.6 mMof nitrite and no interference from other classical anions. Experimental factors that affect electron-transfer rate in these films, such as pH effect and layers number, were systematically analyzed.</span

A Nitrite Electrochemical Sensor Based on Boron‐Doped Diamond Planar Electrochemical Microcells Modified with a Monolacunary Silicotungstate Polyoxoanion

“…The CV curve exhibits two pairs of successive redox waves which shows that (SiW 11 ) has two‐step reduction processes, with formal potentials of −0.4 V (I) and −0.6 V (II), which are close to the values found in the literature with a GC electrode 37, 42; these redox waves correspond to the reduction of the tungsten centers within the SiW 11 (W VI →W V ). Compared to our previous results with GC 36, the reduction peak current of SiW 11 obtained on BDD electrode is considerably higher than that on GC electrode, which is ascribed to the high electrical conductivity of BDD surface.…”

“…Our previous studies showed that the redox process of (SiW 11 ) in acidic solution can be described as follows 36:, …”

“…In our previous work, a glassy carbon electrode (GC) modified by lacunary Keggin structures, was successfully used as catalysts for electrocatalytic reduction of nitrite 36. Based on the knowledge grasped from this paper, we report for the first time the catalytic responses of modified boron‐doped diamond (BDD) microcell in the presence of nitrite.…”

Single crystalline 3C-SiC whiskers used for electrochemical detection of nitrite under neutral condition

“…Moreover, the development of a rapid electrochemical method for nitrite detection without the sample pretreatment prior to analysis and also no interface from other sources (for instance nitrate, sulfate, bromate ions, and oxygen) is highly important. Recently, various kinds of electrochemical nitrite sensors have been fabricated based on the chemical modification of electrode [12][13][14][15][16][17][18][19][20][21][22][23]. In addition, the electrochemical nitrite sensors usually work under weak acidic medium to obtain high sensitivity.…”

Synergistic Effect of Polyoxometalate and Single Walled Carbon Nanotubes on Peroxidase‐like Mimics and Highly Sensitive Electrochemical Detection of Hydrogen Peroxide

“…They can go through a multielectron reversible redox process without any structural changes. This property has been exploited in a wide range of applications such as photoelectrocatalysts [11], energy conversion and storage systems [12] and sensors [13,14].…”