Concurrent Electrocatalysis and Sensing of Hydrazine and Sulfite and Nitrite Ions using Electrodeposited Gold Nanostructure-Modified Electrode

Abstract

Concurrent electrocatalysis and sensing of hydrazine, sulfite ions, and nitrite ions in a mixture were studied using electrodes modified by electrodeposited Au nanostructures (NSs). The β-cyclodextrin-mixed silicate sol-gel composite was dropcasted on the electrode surface and nucleation guided by β-cyclodextrin occurred, followed by the electrodeposition of Au NSs. The additive, β-cyclodextrin, played an evident role as a structure-directing agent; thus, small raspberry-like Au NSs were obtained. The modified electrodes were characterized by surface characterization techniques and electrochemical methods. The Au NSs-modified electrodes effciently electrocatalyzed the oxidation of toxic molecules such as hydrazine and sulfite and nitrite ions even in the absence of any other electron transfer mediator or enzyme immobilization. Wellresolved oxidation peaks along with decreased overpotentials were noticed during the electrooxidation process. The fabricated Au nanostructured electrode clearly distinguished the electrooxidation peaks of each of the three analytes from their mixture.

Simultaneous Detection of Sulfite and Nitrite on Graphene Oxide Nanoribbons‐gold Nanoparticles Composite Modified Electrode

“…The above results suggest that the simultaneous and sensitive detection of SO 3 2− and NO 2 − could be well realized using GCE/GONRs−AuNPs. Some electrochemical sensors for the individual and simultaneous detection of SO 3 2− and NO 2 − are listed in Table 2, which displays the electrode surface, the linear range, the LOD value and the sensitivity [36–47]. The linear range, the LOD value and the sensitivity of the as‐fabricated sensor in the present work are comparable with those of other sensors.…”

Interfacing Silicate Layer Between MoO3 Ribbon and Pt Metaldots Boosts Methanol Oxidation Reaction

“…4. STEM-EDX elemental composition analysis of MoO agent the metal precursors were reduced into sub-2 nm sized Pt MDs and stabilized/embedded by the silicate layer since the 3D silicate sol-gel matrices are well-known candidates for offering a stable environment for metal NPs [24][25][26][27][28][29][30][31]. In addition, porous channels of the silicate layer would enhance mass transport from a electrolyte and electronic access between bare MoO 3 and Pt.…”

Monolayer assembly of gold nanodots on polyelectrolyte support: A multifunctional electrocatalyst for reduction of oxygen and oxidation of sulfite and nitrite

“…Apart from food products, in environment also, sulfite and nitrite ions are co-existing in aquatic ecosystems due to improper wastewater management. 11 Hence, the development of electrocatalytic systems for the simultaneous determination of nitrite and sulfite is highly desirable. 11 In the present work, sub-5 nm methionine (amino acid with thioether functional group)-capped Au nanodots (AuNDs) were successfully self-assembled onto polyelectrolyte, poly(acrylamide-co-diallyldimethylammoniumchloride) (PADA), modified GCE for electrochemical reduction of oxygen and simultaneous oxidation of nitrite and sulfite ions.…”

“…11 Hence, the development of electrocatalytic systems for the simultaneous determination of nitrite and sulfite is highly desirable. 11 In the present work, sub-5 nm methionine (amino acid with thioether functional group)-capped Au nanodots (AuNDs) were successfully self-assembled onto polyelectrolyte, poly(acrylamide-co-diallyldimethylammoniumchloride) (PADA), modified GCE for electrochemical reduction of oxygen and simultaneous oxidation of nitrite and sulfite ions. Interestingly, the monolayer arrangement of AuNDs on the electrode surface effectively avoids the excess gold usage and utilizes the maximum gold surface for catalysis.…”