作者机构：
[He, Quanguo; Li, Guangli; Tian, Yaling; Wu, Yiyong; Liu, Jun] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Hengyang 421008, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[He, Quanguo; Deng, Peihong; Deng, PH; Chen, Dongchu] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.
通讯机构：
[Deng, Peihong] H;[Deng, PH; Chen, DC] F;Hengyang Normal Univ, Hunan Prov Key Lab Funct Met Organ Cpds, Hengyang 421008, Peoples R China.;Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Hengyang 421008, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
摘要：
In this paper, a nanocomposite of cuprous oxide and electrochemically reduced graphene oxide (Cu2O-ERGO) was prepared by a simple and low-cost method; hereby, a new method for the electrochemical determination of tryptophan (Trp) by this composite modified glassy carbon electrode (GCE) is proposed. The prepared materials and modified electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and cyclic voltammetry (CV). The results showed that Cu2O-ERGO/GCE had good electrocatalytic activity for Trp. The effects of supporting electrolyte, scanning rate, accumulation potential, and accumulation time on the determination of Trp were studied. Under the optimum experimental conditions, Trp was quantitatively analyzed by square-wave voltammetry (SWV). The oxidation peak current of Trp had a good linear relationship with its concentration in the range of 0.02-20 M, and the detection limit was 0.01 M (S/N = 3). In addition, the modified electrode has high sensitivity, good repeatability, and long-term stability. Finally, the proposed method has been successfully applied in the determination of Trp concentration in practical samples.
摘要：
A promising sensing platform for the ultrasensitive detection of dopamine (DA) has been constructed using MnO2 nanowires-electrochemically reduced graphene oxide modified glassy carbon electrode (MnO2 NWs-ErGO/GCE). The proposed MnO2 NWs-ErGO/GCEs had the large electrochemical active area and relative low charge transfer resistant (R-ct). As a result, the response peak current of the MnO2 NWs-ErGO is about 13 times higher than that of the bare GCE, demonstrating the remarkable electrocatalytic activity toward DA. The electrochemical kinetics revealed that DA oxidation is quasi-reversible reaction coupling with one electron and two protons. Three linear ranges (0.01 mu M - 0.10 mu M, 0.10 mu M - 1.0 mu M, and 1.0 mu M - 80 mu M) were obtained on the MnO2 NWs-ErGO/GCE, with a low detection limit of 1.0 nM (S/N = 3). Moreover, the response current was almost unaltered even in the presence of 100-fold ascorbic acid (AA) and uric acid (UA), suggesting MnO2 NWs-ErGO has good selectivity toward DA. Finally, the MnO2 NWs-ErGO/GCEs were successfully applied to detect DA in the injection solutions and human blood serum samples with high accuracy and good recovery. (C) 2018 Elsevier Ltd. All rights reserved.
摘要：
In this paper, a tryptophan (Trp) molecularly imprinted chitosan film was prepared on the surface of an acetylene black paste electrode using chitosan as the functional polymer, Trp as the template molecule and sulfuric acid as the crosslinking agent. The surface morphologies of non-imprinted and imprinted electrodes were characterized by scanning electron microscopy (SEM). The formation of hydrogen bonds between the functional polymer and the template molecule was confirmed by infrared spectroscopy. Some factors affecting the performance of the imprinted electrode such as the concentration of chitosan, the mass ratio of chitosan to Trp, the dropping amount of the chitosan-Trp mixture, the solution pH, and the accumulation potential and time were discussed. The experimental results show that the imprinted electrode exhibit good affinity and selectivity for Trp. The dynamic linear ranges of 0.01-4 mu M, 4-20 mu M and 20-100 mu M were obtained by second derivative linear sweep voltammetry, and the detection limit was calculated to be 8.0 nM. The use of the imprinted electrode provides an effective method for eliminating the interference of potentially interfering substances. In addition, the sensor has high sensitivity, reproducibility and stability, and can be used for the determination of Trp in pharmaceutical preparations and human serum samples.
作者机构：
[He, Quanguo; Li, Guangli; Tian, Yaling; Wu, Yiyong; Liu, Jun] Hunan Univ Technol, Sch Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Hengyang 421008, Peoples R China.;[He, Quanguo; Tian, Yaling; Deng, Peihong; Wu, Yiyong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[He, Quanguo; Chen, Dongchu] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.
通讯机构：
[Deng, Peihong] H;[Chen, Dongchu] F;Hengyang Normal Univ, Key Lab Funct Met Organ Cpds Hunan Prov, Hengyang 421008, Peoples R China.;Hengyang Normal Univ, Key Lab Funct Organometall Mat Hunan Prov Univ, Hengyang 421008, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
摘要：
The morphology or shape of nanomaterials plays an important role in functional applications, especially in the electrochemical sensing performance of nanocomposites modified electrodes. Herein, the morphology-dependent electrochemical sensing properties of MnO2-reduced graphene oxide/glass carbon electrode (MnO2-RGO/GCE) toward dopamine detection were investigated. Firstly, various morphologies of nanoscale MnO2, including MnO2 nanowires (MnO2 NWs), MnO2 nanorods (MnO2 NRs), and MnO2 nanotubes (MnO2 NTs), were synthesized under different hydrothermal conditions. Then the corresponding MnO2-RGO/GCEs were fabricated via drop-casting and the subsequent electrochemical reduction method. The oxidation peak currents increase with the electrochemical activity area following the order of MnO2 NWs-RGO/GCE, MnO2 NTs-RGO/GCE, and MnO2 NRs-RGO/GCE. The spatial models for MnO2 NWs, MnO2 NTs, and MnO2 NRs are established and accordingly compared by their specific surface area, explaining well the evident difference in electrochemical responses. Therefore, the MnO2 NWs-RGO/GCE is selected for dopamine detection due to its better electrochemical sensing performance. The response peak current is found to be linear with dopamine concentration in the range of 8.0 × 10−8 mol/L–1.0 × 10−6 mol/L and 1.0 × 10−6 mol/L–8.0 × 10−5 mol/L with a lower detection limit of 1 × 10−9 mol/L (S/N = 3). Finally, MnO2 NWs-RGO/GCE is successfully used for the determination of dopamine injection samples, with a recovery of 99.6–103%. These findings are of great significance for understanding the relationship between unlimited nanoparticle structure manipulation and performance improvement.
作者：
He Quan-Guo;Liang Jing;Li Guang-Li*;Deng Pei-Hong*;Liu Jun;...
期刊：
分析化学,2018年46(3):438-445 ISSN：0253-3820
通讯作者：
Li Guang-Li;Deng Pei-Hong
作者机构：
[He Quan-Guo; Li Guang-Li; Liu Xiao-Peng; Liang Jing; Liu Jun] Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[Deng Pei-Hong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Li Guang-Li; Deng Pei-Hong] H;Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.;Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Xu, Zhifeng] H;Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词：
Copper (II) ion;Ion imprinted polymer;1,8-naphthalimide;Ion recognition;Fluorescence emission
摘要：
In the present study, a fluorescent ion-imprinted sensor (FIIS) for rapid and convenient detection of Cu2+ ions was fabricated. A fluorescent polymerizable ligand, i.e., 4-(2-aminomethyl)pyridine-N-allylnaphthalimide, was designed and synthesized. The FIIS was prepared by surface functionalization of PVDF membrane with a thin layer of copper (II) ion-imprinted polymer using the synthesized ligand as the fluorescent functional monomer. The intensity of fluorescence emission of FIIS decreased linearly with the increase of copper (II) ions concentration in the range of 0-70.0 mu M. The results of selectivity tests indicated that FIIS has high specific recognition ability for Cu2+ ions. The recoveries for the spiked samples were in the range of 96.4-104.4%, and the relative standard deviations (RSDs) were found to be 2.17-4.75%. The FIIS was successfully applied to the determination of copper (II) ions in real water samples. The Limits of detection (LODs) for Cu2+ ions in real water samples were in the range of 0.11-0.14 uM. The present study provided a feasible strategy for construction of fluorescent ion-imprinted sensor for convenient, sensitive and selective detection of metal ions. (C) 2017 Elsevier B.V. All rights reserved.
作者机构：
[He, Quanguo; Li, Guangli; Liu, Jun; Chen, Dongchu; Li, GL] Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.;[He, Quanguo; Li, Guangli; Liu, Xiaopeng; Liu, Jun] Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.;[Xia, Yonghui] Zhuzhou Inst Food & Drug Control, Zhuzhou 412000, Peoples R China.;[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
通讯机构：
[Li, GL; Chen, DC] F;[Li, Guangli] H;Foshan Univ, Sch Mat Sci & Energy Engn, Foshan 528000, Peoples R China.;Hunan Univ Technol, Coll Life Sci & Chem, Zhuzhou 412007, Peoples R China.
关键词：
azo compound;copper;cuprous oxide;FD & C Yellow No. 6;graphite;nanocomposite;oxide;chemistry;electrochemical analysis;electrode;pH;reproducibility;sensitivity and specificity;ultrastructure;Azo Compounds;Copper;Electrochemical Techniques;Electrodes;Graphite;Hydrogen-Ion Concentration;Nanocomposites;Oxides;Reproducibility of Results;Sensitivity and Specificity
