Removable Composite Electrode Made of Silver Nanoparticles on Pyrolyzed Photoresist Film for the Electroreduction of 4-Nitrophenol

Abstract

Access to removable nanocomposite electrodes for electrosensing of pollutants is of great importance. However, the preparation of reproducible and reliable carbon electrodes decorated with metallic nanoparticles, a prerequisite for trustworthy devices, remains a challenge. Here we describe an innovative and easy method to prepare such electrodes. These latter are silicon coated with a thin carbon film on which controlled silver nanostructures are grafted. Different silver nanostructures and surface coverage of the carbon electrode (16, 36, 51, and 67%) can be obtained through a careful control of the time of the hydrogenolysis of the N-N' isopropyl butylamidinate silver organometallic precursor (t = 1, 5, 15, and 60 min, respectively). Importantly, ail nanocomposite surfaces are efficient for the electrodetection of 4 nitrophenol with a remarkable decrease of the overpotential of the reduction of such molecule up to 330 mV. The surfaces are characteriz.ed by atomic force microscopy, gra:zing Electt"Ocatalysis PPF incidence X ray diffraction, scanning electronic microscopy, and Raman spectroscopy. Furthermore, surface enhanced Raman scattering effect is also observed. The exaltation of the Raman intensity is proportional to the surface coverage of the electrode; the number of hot spots increases with the surface coverage.

Topological Analysis of Ag–Ag and Ag–N Interactions in Silver Amidinate Precursor Complexes of Silver Nanoparticles

“…The synthesis of 3, adapted from the report of Lim et al for silver N-N'diisopropylacetamidinate complexes 1 and 2, 18 and its spectroscopic characterization, have been reported elsewhere. 20 The first step of the synthesis, namely the reaction of an alkyllithium with a carbodiimide affording the corresponding lithium amidinate, is followed by a metathesis with a silver halide compound to yield complex 3. Single crystals of 3 were grown from their saturated diethylether solution, kept at -40°C for a week, to allow recrystallization.…”

“…This new silver amidinate precursor has been already used for the preparation of AgNPs in devices for the electrochemical detection of aqueous pollutants. 20 The properties of this new silver amidinate precursor will be further studied for the synthesis of colloidal AgNPs and their assemblies.…”

“…The hydrogenolysis of the latter yielded AgNPs included in devices for the electrochemical detection of aqueous pollutant. 20 The X-ray diffraction characterization of 3 is described hereafter for the first time (Figure 1). Among bridged silver-amidinate complexes, very few other tetranuclear representatives are reported.…”

“…The replacement of the methyl substituent of the central carbon atom of the N , N ′-diisopropylacetamidinate anion by a bulkier n -butyl group allowed for the synthesis of the tetranuclear silver N , N ′-diisopropyl- n -butylamidinate complex 3 (Scheme ). The hydrogenolysis of the latter yielded AgNPs included in devices for the electrochemical detection of aqueous pollutants …”

Insight into the Influence of Analyte Molecular Structure Targeted on MoS2-GO-Coated Electrochemical Nanosensors

“…Clenbuterol (CLB) and 4-nitrophenol (4-NP) have been known as toxic chemical residues in humans. If CLB is found in large doses in animal husbandry productions and human medicine, , 4-NP presents in pesticides, dyes, plasticizers, and even pharmaceuticals. , According to the World Health Organization (WHO) and the U.S. Environmental Protection Agency (U.S. EPA), the use of both of these two chemicals has been banned or limited in most countries. − However, driven by economic interests, illegal abuse of CLB and 4-NPs has not been stopped yet. So far, in an effort to combat such misuse, several fast and simple analytical techniques for precise monitoring of CLB and 4-NP have been developed. ,,, Among them, electrochemical sensors have attracted growing attention because of their high specificity and sensitivity, better stability, rapid response, low price, and high portability.…”