Ultrasensitive and Selective Hydrazine Determination in Water Samples Using Ag–Cu Heterostructures-Grown Indium Tin Oxide Electrode via Environmentally Benign Methods

Abstract

The present study describes the facile and fast growth of Ag–Cu dendritic nanostructures (D-AgCuNSs) via an environmentally benign electro–electroless deposition method and determination of hydrazine (HZ) in water samples using the resultant D-AgCuNSs-grown indium tin oxide (ITO) electrode. HZ was also successfully determined with the aid of Raman spectroscopy, in which the Raman signal was enhanced 15-fold at D-AgCuNSs in the presence of HZ, in contrast to bare ITO. Initially, CuNSs were grown on the ITO substrates at different applied potentials and the resultant substrates were used in the galvanic displacement reaction with Ag+ ions and thereby grown D-AgCuNSs on the ITO substrate. The growth of D-AgCuNSs was followed by scanning electron microscopy (SEM), with respect to time and Ag+ concentration. The D-AgCuNSs grown on ITO substrates were further characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive spectroscopy (EDS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. XPS shows that the grown D-AgCuNSs contain zerovalent Ag and Cu. Furthermore, the D-AgCuNSs-modified ITO electrode was utilized for carcinogenic HZ determination and excellent catalytic activity was observed at this electrode, in contrast to bare and Cu-modified ITO electrodes. The amperometric determination was accomplished with a wide range of HZ concentrations, from 20 × 10–9 M to 50 × 10–6 M (correlation coefficient of R 2 = 0.9934). Furthermore, the ITO/D-AgCuNSs electrode detects HZ with the superior selectivity of 2500-fold in the presence of common interfering ions and biological compounds. The lowest limit of detection (0.12 nM (signal-to-noise (S/N) ratio of 3)) and superior sensitivity (3722 μA mM–1 cm–2) were achieved toward HZ. In addition, the present sensor was exploited for the determination of HZ in environmental samples and exhibits excellent recovery.

Negative Potential-Induced Growth of Surfactant-Free CuO Nanostructures on an Al–C Substrate: A Dual In-Line Sensor for Biomarkers of Diabetes and Oxidative Stress

“…While the electrodeposition is being driven to more negative potentials, the reduction current also increases, indicating the dense deposition of CuO. Electrodeposition of Cu [Cu 2+ + 2e – = Cu 0 ( E 0 = 0.339 V vs SHE)] is driven by a constant deposition potential that induces the growth rate and ultimately the morphology, and thus, the morphology of the electrodeposited CuO nanostructures was analyzed by SEM with respect to different applied potentials (Figure ). Because the formation of CuO nanostructures is due to deposition followed by nucleation, different morphologies were observed with respect to different deposition potentials.…”

“…The introduced defects from the competition of (0 2 2) and (2 0 2) planes performed as an electron trapper and subsequently reduced the electron density. The heterogeneous rate constant for electron transfer ( k et ) can be obtained from eq . , where R , T , and F have their usual meanings and values, A is the electrode area (1 cm 2 ), C 0 is the concentration of Fe­(CN) 6 3–/4– (5 mM), and n is number of electrons involved. The obtained k et values are 2.75 × 10 –4 , 1.34 × 10 –4 , 1.07 × 10 –4 , and 1.32 × 10 –4 cm s –1 for the CuO nanostructures fabricated at −0.1, −0.3, −0.5, and −0.7 V, respectively.…”

“…This is due to not only their low cost but also their superior electrocatalytic activity and promote the expected redox reactions at lower overpotentials. − Owing to their narrow band gap energy, miniaturization, and easily tuned nanoarchitecture, plenty of Cu-based nanomaterials have been investigated for the determination of glucose and H 2 O 2 . − Miniaturized CuO nanostructures with a band gap energy of ≤1.6 eV have been more widely employed than the bulk in the manufacturing of solar cell panels, electro- and photocatalysis, chemical, gas and biosensors, electrochromic devices, and superconducting materials. − In terms of cost effectiveness, environmental friendliness, and chemical stability, a great deal of effort has been spent on the development of CuO nanostructures, including thermal decomposition and oxidation and hydrothermal preparation, ultrasonic irradiation, and electron beam lithography. − However, the involvement of hazardous chemicals and surfactants and relatively tedious synthetic procedures made the materials unsuitable in real-time applications. Electrodeposition has been established as a decent and fascinating approach for fabricating surfactants and template-free nanostructures on the electrode surface with high yields. ,− Because the active surface sites of the sensor were blocked by the surfactants, the surfactant-capped nanostructures fabricated electrochemical sensors unfortunately exhibit poorer performance. Moreover, post-treatments are required to remove the surfactants from the fabricated electrocatalysts, which results in a morphological collapse.…”

“…It is determined that the sensing behavior is mainly favored by the morphology, grain size, pore size, and composition. A weird morphology may exhibit a remarkable activity to enhance the sensitivity of the electrode, and hence, tuning the shape of the nanomaterials is one of the important criteria in the electrocatalysis and can be readily controlled by electrodeposition. ,− More importantly, immobilization of nanomaterials can be performed without any additional procedure on the electrode surface.…”

Electrochemical Scaffold Based on Silver Phosphate Nanoparticles for the Quantification of Acetaminophen in Body Fluids and Pharmaceutical Formulations

“…Silver (Ag) and Ag-based nanomaterials are well-known for their antibacterial and inhibitory behaviors by possessing low toxicity to human cells. In the past decades, Ag related nanostructures have increasingly been utilized for infection treatment because of their surprising properties resulting from the nanoscale characteristics and the capability to swiftly release of several Ag species which were seen to improve the treatment effectiveness. − Moreover, the catalytic activity of the Ag-based nanomaterials has been well established. − In this category, silver phosphate (Ag–P) is a member of the Ag family, which has an indirect band gap of 2.36 eV as well as a direct bandgap of 2.43 eV and has been recognized as one of the most effective visible-light-driven photocatalytic materials; its utility as a photocatalyst has been well established. − The morphology of Ag–P crystals has recently qualified it for wide utilization in biocompatible and bacteriostatic fields. Phosphate can perform as a capping as well as stabilizing agent for the high yield of Ag–P NPs without any external agents.…”