Carbohydrates-Derived Nitrogen-Doped Hierarchical Porous Carbon for Ultrasensitive Detection of 4-Nitrophenol

Abstract

A facile, cost-effective approach to obtain sensor electrode materials with excellent electrochemical performance for sensitive and fast detection of 4-nitrophenol (4-NP) is of great importance to the environment and human health. Herein, a smart strategy was proposed for fabrication of nitrogen-doped hierarchical porous carbon (NPC) material with large surface area and unique hierarchical porous structure derived from conveniently available carbohydrates via a facile process. NPC combined with chitosan (CTS) was used to modify an indium-tin oxide (ITO) electrode, referred to as a CTS/​NPC/​ITO electrode, in which CTS acted as dispersant and immobilization reagent. On the basis of the optimum conditions, 4-NP was successfully deposited on a CTS/​NPC/​ITO electrode and the cathodic deposit of 4-NP showed reversible characteristics in a potential range between −0.22 and −0.00 V as well as high ionic-electronic conductivity. Moreover, the electrochemical reaction kinetics and mechanism of 4-NP were explored in detail by CVs, FTIR spectra, and LC–MS. The response sensitivities of the electrode for 4-NP were obtained as 4.85 μA μM–1, 2.212 μC μM–1, and 0.118 μA μM–1 (RSD ∼ 5%) while detection limits (S/N = 3) were 27.55, 30.10, and 5.44 μM by applying cyclic voltammetry, chronocoulometry, and differential pulse voltammetry, respectively. The results were presented to demonstrate that the CTS/​NPC/​ITO electrode had excellent reproducibility, repeatability, good stability, and high selectivity for detecting 4-NP in real water samples.

Simultaneous Square Wave Voltammetric Detection of Endocrine-Disrupting Agents Using a Nanocomposite of Magnetic Fe3O4Nanorods and Poly(3,4-Methylenedioxy)aniline

“…Based on Figure 4b−d, two linear segments in the calibration curves were observed for BPA and phenol with two different slopes, while the calibration curve for 4-NP showed just one linear segment, which is consistent with previous reports in the literature. 1,14,15 The two linear segments indicated that the MNR-PMDAN nanocomposite behaved differently in low and high concentrations of BPA and phenol. Previous studies have reported that the current signals were directly proportional to the concentration of the analytes and ESA; therefore, at lower concentrations of analytes, MNR-PMDAN/GPE would have access to a larger effective surface area when compared to that at higher concentrations of the analytes.…”

“…9,11 Recently, electrodes with silver nanoparticles immobilized on carbon nanotubes were developed for the simultaneous electrochemical determination of phenol and BPA by Goulart et al 12 A novel nanocomposite consisting of microspheres of the poly(dopamine quinone-chromium(III) complex) was used for the detection of phenol and 4-NP by Shahbakhsh and Noroozifar. 1 In addition, several groups have performed the electrochemical detection of 4-NP alone using modified electrodes with various nanocomposites consisting of gold− zinc sulfide nanocomposite nanorods, 13 carbohydrate-derived nitrogen-doped hierarchical porous carbon, 14 and ultrathin sulfur-doped graphitic carbon nitride nanosheets. 15 Moreover, Arfin et al 16 used a graphene oxide−zinc oxide nanocomposite for the detection of phenol, while Bolat et al 17 and Feng et al 18 reported a poly(cetyltrimethylammonium bromide)multiwalled carbon nanotube-based composite and hememodified screen printed electrodes, respectively, that can only detect BPA.…”

Chitosan-derived N-doped carbon catalysts with a metallic core for the oxidative dehydrogenation of NH–NH bonds

“…The peaks in the range of 398.0–398.4, 399.6–400.5, 400.7–402 and 401.4–405.8 eV can be attributed to pyridinic N, pyrrolic N, graphitic N, and pyridinic N-oxides, respectively. 35 It could be clearly observed that pyridinic N and pyrrolic N were the dominant phases in all three catalysts. The second highest intensity was analyzed for the graphitic N moieties, while N-oxides were detected as minor components in all three catalysts.…”

Electroactive Covalent Organic Frameworks/Carbon Nanotubes Composites for Electrochemical Sensing

“…Electrochemical sensing is attracting more and more attention because of its ease of operation, low cost, rapid response, etc. − Electroactive or catalytically active materials themselves and their assembly, as well as the distribution on electrodes, will affect the electrochemical sensor’s performance including sensitivity, repeatability, stability, selectivity, etc. − Although some electroactive materials or materials with catalytic activity such as nanomaterials and nanocomposites (NPs) with large specific surface area and good catalytic activity, including metal/metal oxide NPs, ,, carbon nanotubes (CNTs), − graphene, − porous carbon, − etc., can greatly improve the sensitivity and linear range of electrochemical sensing, these nanomaterials tend to pile up and fall off from the surface of the electrode, leading to poor stability and repeatability. Therefore, there is a growing need to develop some low-cost, highly electroactive/catalytically active, and dispersive materials for high-performance sensing.…”