共查询到20条相似文献,搜索用时 62 毫秒
1.
Jun Zhu Dheeraj Singh Chauhan Dan Shan Xiao-Yan Wu Guang-Yao Zhang Xue-Ji Zhang 《Mikrochimica acta》2014,181(7-8):813-820
A glassy carbon electrode (GCE) was modified with pyrocatechol violet (PCV) that was electrodeposited on single walled carbon nanotubes (SWCNTs) via continuous cycling between 0 and 0.9 V (vs. SCE). The resulting electrode exhibits excellent electrocatalytic activity towards the oxidation of hydrazine at 0.3 V. The apparent surface coverage of the electrode is at least 24 times higher (2.7?×?10?10 mol cm?2) than that obtained with a bare GCE (1.1?×?10?11 mol cm?2). This is attributed to a remarkably strong synergistic effect between the acid-pretreated SWCNTs and the electrodeposited PCV coating. Response is fast (2 s) and sensitive (281 mA M?1 cm?2). Other features include a wide linear range (150 nM to 0.4 mM) and a low detection limit (150 nM at an SNR of 3). The sensor has been successfully applied to the determination of hydrazine in water and cigarette samples with good accuracy and precision. In addition, the morphology and the wetting properties of the coating were studied by scanning electromicroscopy and contact angle measurements. Figure
A glassy carbon electrode (GCE) was modified with pyrocatechol violet (PCV) that was electrodeposited on single walled carbon nanotubes (SWCNTs). The resulting electrode exhibits excellent electrocatalytic activity towards the oxidation of hydrazine at 0.3 V with fast response, wide linear range and a low detection limit. 相似文献
2.
Su-Juan Li Guo-Yan Zhao Rong-Xia Zhang Ya-Li Hou Lin Liu Huan Pang 《Mikrochimica acta》2013,180(9-10):821-827
We describe a highly sensitive and selective amperometric sensor for the determination of nitrite. A glassy carbon electrode was modified with a composite made from gold nanoparticles (AuNPs) and sulfonated graphene (SG). The modified electrode displays excellent electrocatalytic activity in terms of nitrite oxidation by giving much higher peak currents (at even lower oxidation overpotential) than those found for the bare electrode, the AuNPs-modified electrode, and the SG-modified electrode. The sensor has a linear response in the 10 μM to 3.96 mM concentration range, a very good detection sensitivity (45.44 μA mM?1), and a lower detection limit of 0.2 μM of nitrite. Most common ions and many environmental organic pollutants do not interfere. The sensor was successfully applied to the determination of nitrite in water samples, and the results were found to be consistent with the values obtained by spectrophotometry. Figure
A highly sensitive amperometric sensor for nitrite using a glassy carbon electrode modified with gold nanoparticles/sulfonated graphene (AuNPs/SG) composites is presented 相似文献
3.
A novel glucose biosensor is presented as that based on a glassy carbon electrode modified with hollow gold nanoparticles (HGNs) and glucose oxidase. The sensor exhibits a better differential pulse voltammetric response towards glucose than the one based on conventional gold nanoparticles of the same size. This is attributed to the good biological conductivity and biocompatibility of HGNs. Under the optimal conditions, the sensor displays a linear range from 2.0?×?10?6 to 4.6?×?10?5?M of glucose, with a detection limit of 1.6?×?10?6?M (S/N?=?3). Good reproducibility, stability and no interference make this biosensor applicable to the determination of glucose in samples such as sports drinks. Figure
A novel glucose biosensor was prepared based on glucose oxidase, hollow gold nanoparticles and chitosan modified glassy carbon electrode. The electrode showed a good response for the glucose. The sensor has been verified by the determination of glucose in sport drink 相似文献
4.
Miao Han Ying Qu Shiqin Chen Yali Wang Zhi Zhang Ming Ma Zhengguo Wang Guoqing Zhan Chunya Li 《Mikrochimica acta》2013,180(11-12):989-996
We have prepared a nanocomposite consisting of single-walled carbon nanotubes and polylysine. It was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, and by UV/vis and FTIR spectroscopy. Tyrosinase was covalently immobilized on the nanocomposite, and the resulting bioconjugate deposited on a glassy carbon electrode to form a biosensor for bisphenol A. The biosensor was characterized by scanning electron microscopy and electrochemical impedance spectroscopy. Under optimized experimental conditions, the biosensor gives a linear response to bisphenol A in the 4.00 nM to 11.5 μM concentration range. Its sensitivity is 788 mA M?1 cm?2, and the lower detection limit is 0.97 nM (at an S/N of 3). The biosensor shows good repeatability, reproducibility and long-term stability. In a preliminary practical application, it was successfully applied to the determination of bisphenol A in leachates of plastic spoons. Figure
Single-walled carbon nanotubes-polylysine (SWCNT-PLL) nanocomposite was prepared and thoroughly characterized. The obtained nanocomposite was used as a platform to immobilize tyrosinase (Tyr) onto a glassy carbon electrode (GCE) to fabricate a biosensor for bisphenol A (BPA) 相似文献
5.
A highly sensitive electrochemical sensor for determination of L-cysteine (CySH) is presented. It is based on vertically aligned multiwalled carbon nanotubes modified with Pt nanoparticles by magnetron sputtering deposition. The morphology of the nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy and energy-dispersive. The electrochemistry of CySH was investigated by cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The mechanism for the electrochemical reaction of CySH at the modified electrode at different pH values is discussed. The electrode exhibits a higher electrocatalytic activity towards the oxidation of CySH than comparable other electrodes. It displays a linear dependence (R 2?=?0.9980) on the concentration of CySH in the range between 1 and 500 μM and at an applied potential of +0.45 V, a remarkably low detection limit of 0.5 μM (S/N?=?3), and an outstandingly high sensitivity of 1.42?×?103 μA?mM?1?cm?2, which is the highest value ever reported. The electrode also is highly inert towards other amino acids, creatinine and urea. The sensor was applied to the determination of CySH in urine with satisfactory recovery, thus demonstrating its potential for practical applications. Figure
Pt nanoparticles on carbon nanotubes by sputtering deposition show high performance for L-cysteine sensing 相似文献
6.
Xiaohua Zhu Qifang Jiao Chuyi Zhang Xiaoxi Zuo Xin Xiao Yong Liang Junmin Nan 《Mikrochimica acta》2013,180(5-6):477-483
We have developed a stable and sensitive nonenzymatic glucose sensor by modifying a glassy carbon electrode (GCE) with a composite incorporating nickel(II) oxides and reduced graphene. The oxides were generated by directly electrodepositing nickel on the GCE with a graphene modifier using a multi-potential pulse process, and then oxidizing nickel to nickel(II) oxides by potential cycling. In comparison to the conventional nickel(II) oxides-modified GCE, this new nickel(II) oxides-graphene modified GCE (NiO-GR/GCE) has an about 1.5 times larger current response toward the nonenzymatic oxidation of glucose in alkaline media. The response to glucose is linear in the 20 μM to 4.5 mM concentration range. The limit of detection is 5 μM (at a S/N of 3), and the response time is very short (<3 s). Other beneficial features include selectivity, reproducibility and stability. A comparison was performed on the determination of glucose in commercial red wines by high-performance liquid chromatography (HPLC) and revealed the promising aspects of this sensor with respect to the determination of glucose in real samples. Figure
A stable and sensitive nonenzymatic glucose sensor is developed by preparing the nickel(II) oxides-reduced graphene nanocomposite modified glassy carbon electrode (NiO-GR/GCE), and then used to detect the glucose contents in the commercial red wines. This NiO-GR/GCE also has a high selectivity 相似文献
7.
Honghui Liu Yanling Chen Yunchun Liu Zhousheng Yang 《Journal of Solid State Electrochemistry》2013,17(10):2623-2631
This work described a novel sensor for detection of l -tryptophan (Trp) by electrodeposition of gold nanoparticles (AuNPs) onto the poly(alizarin red S) film pre-cast on a glassy carbon electrode (GCE). Alizarin red S (ARS) was deposited on the surface of the GCE by electropolymerization, and gold nanoparticles (AuNPs) were attached onto the poly(ARS) film by electrodeposition, forming an AuNPs–PARS nanocomposite film-modified GCE (AuNPs–PARS/GCE). Then electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) were used to characterize modified electrodes. The Nyquist diagrams of EIS indicated that the PARS film and AuNPs were successfully immobilized on the surface of GCE, and the electron transfer resistance value of electrode changed efficiently. The SEM image showed that the immobilized AuNPs were spherical in shape. The AuNPs–PARS/GEC displayed excellent amperometric response for Trp. The amperometric responses have two linear ranges from 0.02 to 0.5 μM and 0.5 to 20.0 μM, with sensitivities of 1.63(±0.08) and 0.21(±0.01)?μAμM?1, respectively. Its detection limit was 6.7 nM at a signal-to-noise ratio of 3. The proposed method was applied to determine Trp. Figure
The procedure of the L-tryptophan sensor preparation 相似文献
8.
We report on a biosensor for organophosphate pesticides (OPs) by exploiting their inhibitory effect on the activity of acetylcholinesterase (AChE). A boron-doped diamond (BDD) electrode was modified with a nanocomposite prepared from carbon spheres (CSs; with an average diameter of 500 nm) that were synthesized from resorcinol and formaldehyde, and then were coated with gold nanoparticles (AuNPs) by chemically growing them of the CSs. Compared to a bare BDD electrode, the electron transfer resistance is lower on this new electrode. Compared to an electrode without Au-NPs, the peak potential is negatively shifted by 42 mV, and the peak current is increased by 55 %. This is ascribed to the larger surface in the AuNP-CS nanocomposite which improves the adsorption of AChE, enhances its activity, and facilitates electrocatalysis. Under optimum conditions, the inhibitory effect of chlorpyrifos is linearly related to the negative log of its concentration in the 10?11 to 10?7 M range, with a detection limit of 1.3?×?10?13 M. For methyl parathion, the inhibition effect is linear in the 10?12 to 10?6 M range, and the detection limit is 4.9?×?10?13 M. The biosensor exhibits good precision and acceptable operational and temporal stability. Figure
A novel acetylcholinesterase-based biosensor based on a boron-doped diamond electrode modified with gold nanoparticles and carbon spheres was firstly prepared to detect organophosphate pesticides. This biosensor exhibited higher sensitivity, lower detection limit, good reproducibility and acceptable stability. 相似文献
9.
We have prepared a glassy carbon electrode modified with poly-2,6-pyridinedicarboxylic acid and with magnetic Fe3O4 nanoparticles. This modification enhances the effective surface area and the electrocatalytic oxidation of nicotinamide adenine dinucleotide (NADH) in addition to providing positively charged groups for electrostatic assembly of the phosphate group of NADH. The modified electrode responds linearly to NADH in the range from 5?×?10?8 to 2.5?×?10?5?M and gives a lower detection limit of 1?×?10?8?M. It displays satisfactory selectivity and reproducibility. The sensor was applied to rapid screening of plant extracts for their antioxidant properties. Figure
Poly-2,6-pyridinedicarboxylic acid (PDC) was fabricated by electropolymerizing 2,6-pyridinedicarboxylic acid with cyclic voltammetry (CV) on the glassy carbon electrode (GCE) surface. The magnetic Fe3O4 nanoparticles treated with aminopropyltriethoxysilane (APTS) modified on the PDC/GCE to form APTS-Fe3O4/PDC composite film. The APTS-Fe3O4/PDC film had enhanced the effective electrode surface area and provided positively charged groups for electrostatic assembly of phosphate group of NADH. 相似文献
10.
Zuchao Meng Bin Liu Jianbin Zheng Qinglin Sheng Hongfang Zhang 《Mikrochimica acta》2011,175(3-4):251-257
We describe a modified glassy carbon electrode (GCE) for the sensitive determination of nitrite in waste water samples. The GCE was modified by electrodeposition of cobalt oxide nanoparticles on multi-walled carbon nanotubes (MWCNTs) deposited on a conventional GCE. Scanning electron microscopy and electrochemical techniques were used for the characterization of the composite material which is very uniform and forms a kind of nanoporous structure. Electrochemical experiments showed that the modified electrode exhibited excellent electrocatalytic properties for nitrite. Amperometry revealed a good linear relationship between peak current and nitrate concentration in the 0.5 to 250???M range with a detection limit of 0.3???M (S/N?=?3). The method has been applied to the amperometric detection of nitrite. The modified electrode displays good storage stability, reproducibility, and selectivity for a promising practical application. Figure
The dense and entangled CoOx/MWCNTs nanocomposite showed a three-dimensional nanoporous structure. The three-dimensional nanoporous structure provided ample space to allow fast mass transport of ions through the electrolyte/electrode interface as well as a conductive network for enhancing electronic conductivity which was favorable to the catalytic application of CoOx. 相似文献
11.
We describe a glassy carbon electrode (GCE) modified with a film composed of Nafion and TiO2-graphene (TiO2-GR) nanocomposite, and its voltammetric response to the amino acids L-tryptophane (Trp) and L-tyrosine (Tyr). The incorporation of TiO2 nanoparticles with graphene significantly improves the electrocatalytic activity and voltammetric response compared to electrodes modified with Nafion/graphene only. The Nafion/TiO2-GR modified electrode was used to determine Trp and Tyr with detection limits of 0.7 and 2.3 μM, and a sensitivity of 75.9 and 22.8 μA mM?1 for Trp and Tyr, respectively. Figure
The electrochemical sensor based on Nafion/TiO2-GR composite film modified GCE was presented. The integration of TiO2 nanoparticles with graphene provides an efficient microenvironment to promote the electrochemical reaction of amino acids Trp and Tyr. The fabricated electrochemical sensor exhibits favorable analytical performance for Trp and Tyr, with high sensitivity, low detection limit and good reproducibility. 相似文献
12.
We report on a highly sensitive and selective nonenzymatic glucose sensor based on a glassy carbon electrode modified with a composite prepared from nickel(II) hydroxide nanoplates and carbon nanofibers. The nanocomposite was characterized by scanning electron microscopy and powder X-ray diffraction. Electrodes modified with pure Ni(OH)2 and with the nanocomposite were characterized by electrochemical impedance spectroscopy. Cyclic voltammetric and amperometric methods were used to investigate the catalytic properties of the modified electrodes for glucose electrooxidation in strongly alkaline solution. The sensor exhibits a wide linear range (from 0.001 to 1.2 mM), a low detection limit (0.76 μM), fast response time (< 5 s), high sensitivity (1038.6 μA?·?mM?1?·?cm?2), good reproducibility, and long operational stability. Application of the nonenzymatic sensor for monitoring glucose in real samples was also demonstrated. Figure
We report on a highly sensitive and selective nonenzymatic glucose sensor based on a glassy carbon electrode modified with a nanocomposite prepared from nickel (II) hydroxide nanoplates and carbon nanofibers. The facile preparation, high electrocatalytic activity, relatively fast response, favorable reproducibility and long-term performance stability demonstrate the potential applications of the sensor. 相似文献
13.
Shuyun Zhu Jiao Zhang Xian-en Zhao Hua Wang Guobao Xu Jinmao You 《Mikrochimica acta》2014,181(3-4):445-451
We report a simple method for the direct and quantitative determination of L-tryptophan (Trp) and L-tyrosine (Tyr) using a glassy carbon electrode (GCE) modified with single-walled carbon nanohorns (SWCNHs). The SWCNH modified GCE exhibits high electrocatalytic activity towards the oxidation of both Trp and Tyr. It shows a linear response to Trp between 0.5 and 50 μM and to Tyr between 2 and 30 μM. The detection limits for Trp and Tyr are 50 nM and 400 nM, respectively. In addition, the modified GCE displays good selectivity and good sensitivity, thus making it suitable for the determination of Trp and Tyr in spiked serum samples. Figure
The electrochemical sensor based on single-walled carbon nanohorns modified glassy carbon electrode was presented. The fabricated electrochemical sensor exhibits favorable analytical performance for L-tryptophan and L-tyrosine with high sensitivity, low detection limit, and good reproducibility. 相似文献
14.
Shanshan Ji Zhe Yang Chao Zhang Yue-E Miao Weng Weei Tjiu Jisheng Pan Tianxi Liu 《Mikrochimica acta》2013,180(11-12):1127-1134
A glassy carbon electrode (GCE) was modified with nickel(II) hydroxide nanoparticles and a film of molybdenum sulfide. The nanocomposite was prepared by two-step electrodeposition. Scanning electron microscopy reveals that the nanoparticles are uniformly deposited on the film. Cyclic voltammetry and chronoamperometry indicate that this modified GCE displays a remarkable electrocatalytic activity towards nonenzymatic oxidation of glucose. Response is linear in the 10–1,300 μM concentration range (R 2 ?=?0.9987), the detection limit is very low (5.8 μM), response is rapid (< 2 s), and selectivity over ascorbic acid, dopamine, uric acid, fructose and galactose is very good. Figure
An efficient nonenzymatic glucose sensor based on Ni(OH)2/MoSx nanocomposite modified glassy carbon electrode has been fabricated via a two-step electrodeposition approach. The resulting nonenzymatic sensor exhibits excellent properties toward glucose detection, such as low detection limit, fast response and noticeable selectivity. 相似文献
15.
Highly sensitive sensor for detection of NADH based on catalytic growth of Au nanoparticles on glassy carbon electrode 总被引:1,自引:0,他引:1
Lin Tang Guangming Zeng Guoli Shen Yi Zhang Yuanping Li Changzheng Fan Can Liu Chenggang Niu 《Analytical and bioanalytical chemistry》2009,393(6-7):1677-1684
In this work, an electrochemical dihydronicotinamide adenine dinucleotide (NADH) sensor based on the catalytic growth of Au nanoparticles (Au NPs) on glassy carbon electrode was developed. Catalyzed by Au NPs immobilized on pretreated glassy carbon electrode, the reduction of AuCl4 ? in the presence of hydroquinone and cetyltrimethyl ammonium chloride led to the formation of enlarged Au NPs on the electrode surface. Spectrophotometry and high-resolution scanning electronic microscope (SEM) analysis of the sensor morphologies before and after biocatalytic reaction revealed a diameter growth of the nanoparticles. The catalytic growth of Au NPs on electrode surface remarkably facilitated the electron transfer and improved the performance of the sensor. Under optimal conditions, NADH could be detected in the range from 1.25?×?10?6 to 3.08?×?10?4 M, and the detection limit was 2.5?×?10?7 M. The advantages of the proposed sensor, such as high precision and sensitivity, fast response, low cost, and good storage stability, made it suitable for on-line detection of NADH in complex biological systems and contaminant degradation processes. Figure
Schematic presentation of the bioelectrocatalytic sensing of NADH 相似文献
16.
A biosensor for hydrogen peroxide was constructed by immobilizing horseradish peroxidase on chitosan-wrapped NiFe2O4 nanoparticles on a glassy carbon electrode (GCE). The electron mediator carboxyferrocene was also immobilized on the surface of the GCE. UV?Cvis spectra, Fourier transform IR spectra, scanning electron microscopy, and electrochemical impedance spectra were acquired to characterize the biosensor. The experimental conditions were studied and optimized. The biosensor responds linearly to H2O2 in the range from 1.0?×?10?5 to 2.0?×?10?3?M and with a detection limit of 2.0?×?10?6?M (at S/N?=?3). Figure
A biosensor for hydrogen peroxide was constructed by immobilizing horseradish peroxidase on chitosan-wrapped NiFe2O4 nanoparticles on a glassy carbon electrode. 相似文献
17.
Julien Gigault Bruno Grassl Isabelle Le H��cho Ga?tane Lespes 《Mikrochimica acta》2011,174(3-4):265-271
We have prepared a kind of molecularly imprinted nano-porous sensing film for the adsorption of melamine. It consists of a graphite electrode impregnated with paraffin and modified with melamine, chitosan, silver nanoparticles and polyquercetin by employing an electrochemical method. The film displays excellent and highly selective sorption of melamine in the 3-dimensional porous nanomaterial, and this was applied to the determination of melamine in dairy products. The electrode responds linearly to melamine in the concentration range of 1?×?10?8 to 9?×?10?7?M, with a detection limit of 1.3?×?10?9?M (at 3??) in real samples, and with recoveries in the range of 99 to 102%. The surface structure and composition of the sensor was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and electrochemical techniques. The interaction between the porous film and melamine was also studied by using hexacyanoferrate (III) as an electrochemical indicator. Figure
Extremely sensitive sensor for melamine used a kind of molecularly mprinted nano-porous film, which displays an excellent and highly selective sorption to melamine in the 3-dimensional porous nanomaterial. The interaction between the porous film and melamine also was studied by using hexacyanoferrate (III) as an electrochemical indicator. 相似文献
18.
We have developed a sensor for the square wave anodic stripping voltammetric determination of Pb(II). A glassy carbon electrode was modified with a thin film of an antimony/poly(p-aminobenzene sulfonic acid) composite in air-saturated aqueous solution of pH 2.0. Compared to a conventional antimony film electrode, the new one yields a larger stripping signal for Pb(II). The conditions of polymerization, the concentration of Sb(III), the pH value of the sample solution, the deposition potential and time, frequency, potential amplitude, and step increment potential were optimized. Under the optimum conditions, a linear response was observed for Pb(II) in the range of 0.5 to 150.0 μg?L?1. The detection limit for Pb(II) is 0.1 μg?L?1. Figure
The surface of a glassy carbon electrode (GCE) was modified by electropolymerization of p-aminobenzene sulfonic acid (p-ABSA) and the modified electrode was then prepared by in situ depositing antimony and target metal on the poly(p-ABSA) coated glassy carbon electrode. The antimony/poly(p-ABSA) film electrode displays high electrochemical activity in giving a peak current that is proportional to the concentration of Pb(II) in a certain range. 相似文献
19.
Su-Juan Li Ji-Min Du Jia-Ping Zhang Meng-Jie Zhang Jing Chen 《Mikrochimica acta》2014,181(5-6):631-638
We have prepared a graphene-based hybrid nanomaterial by electrochemical deposition of cobalt oxide nanoparticles (CoOxNPs) on the surface of electrochemically reduced graphene oxide deposited on a glassy carbon electrode (GCE). Scanning electron microscopy and cyclic voltammetry were used to characterize the immobilized nanoparticles. Electrochemical determination of H2O2 is demonstrated with the modified GCE at pH 7. Compared to GCEs modified with CoOxNPs or graphene sheets only, the new electrode displays larger oxidative current response to H2O2, probably due to the synergistic effects between the graphene sheets and the CoOxNPs. The sensor responds to H2O2 with a sensitivity of 148.6 μA mM?1 cm?2 and a linear response range from 5 μM to 1 mM. The detection limit is 0.2 μM at a signal to noise ratio (SNR) of three. The method was successfully applied to the determination of H2O2 in hydrogen peroxide samples. Figure
A highly sensitive H2O2 sensor using a glassy carbon electrode modified with cobalt oxide nanoparticles/electrochemical reduced graphene oxide (CoOxNPs/ERGO) hybrids is presented. 相似文献
20.
We report on an electrode for the amperometric determination of lorazepam. A glassy carbon electrode was coated with a molecular imprint made by electropolymerization of ortho-phenylenediamine and filled with multiwalled carbon nanotubes and gold nanoparticles, which enhances the transmission of electrons. The sensor was studied with respect to its response to hexacyanoferrate (III) as a probe and by electrochemical impedance spectroscopy, cyclic voltammetry and square wave voltammetry. The linear response range to Lorazepam is from 0.5 nM to 1.0 nM and from 1.0 nM to 10.0 nM, with a detection limit of 0.2 nM (at an S/N of 3). The electrode was successfully applied to determine Lorazepam in spiked human serum. Figure 1
The preparation of schematic of the AuNP/MIP/f?MWCNT/GCE electrode 相似文献