电化学沉积纳米金和石墨烯修饰离子液体碳糊电极检测芦丁的研究

以六氟磷酸正己基吡啶为粘合剂和修饰剂,制备了离子液体修饰碳糊电极(CILE)。用电化学方法依次将纳米金和石墨烯(GR)电沉积在CILE表面制备了相应的修饰电极(GR/Au/CILE)。电极表面纳米金和GR的存在极大地提高了电极的电化学性能。进一步用循环伏安法、示差脉冲伏安法和计时库仑法等电化学方法研究了芦丁在GR/Au/CILE上的电化学行为,求解了相关的电化学参数。在最佳实验条件下,芦丁的氧化峰电流与其浓度在8.0×10"8～8.0×10"5mol/L范围内呈现良好的线性关系,检出限为2.55×10"8mol/L(3σ)。将本方法应用于复方芦丁片样品的测定,结果令人满意。     

基于石墨烯-纳米金修饰分子印迹传感器测定黑茶中芦丁

在金电极表面滴涂石墨烯(GR),通过电沉积技术沉积纳米金(Au)构成石墨烯-纳米金修饰电极(Au-GR/GE)。以芦丁为模板分子,邻氨基酚为功能单体,通过电聚合反应在Au-GR/GE表面合成一种对芦丁具有特异性识别能力的分子印迹传感器膜(MIP)。采用循环伏安法(CV)、差分脉冲伏安法(DPV)研究了印迹膜的性能、结构和分子印迹效应,并与槲皮素进行了选择性响应的比较,发现此传感器对芦丁具有良好的选择性。在最佳实验条件下,其对芦丁浓度的定量测定线性范围为6.30×10-7~1.70×10-4mol/L,线性方程为I(μA)=3.8136-8.6247 lg c(mol/L),R=0.9961,检出限为2.10×10-7mol/L。     

石墨烯修饰的三唑磷分子印迹电化学传感器的制备

采用石墨烯作为电极增敏材料,制备三唑磷(TAP)分子印迹电化学传感器。采用自由基聚合法,在石墨烯修饰电极(GR/GCE)上合成分子印迹聚合物膜(MIP)。利用微分脉冲伏安法、电化学阻抗谱对不同修饰电极进行电化学表征,利用微分脉冲伏安法考察了MIP和非分子印迹聚合物膜(NIP)传感器的电化学性能。在最优实验条件下,TAP浓度在1.0×10~(-7)～2.0×10~(-5)mol·L~(-1)内和MIP膜传感器峰电流呈线性关系,检出限为4.3×10~(-8)mol·L~(-1)(S/N=3)。建立MIP膜传感器的动力学吸附模型,测得结合速率常数k为9.0580 s。     

尼泊金乙酯分子印迹膜电化学传感器的制备

以邻苯二胺为功能单体,尼泊金乙酯为模板分子,通过电化学聚合在玻碳电极表面制备了尼泊金乙酯分子印迹膜,采用循环伏安法及方波伏安法,以K3[Fe(CN)6]为电活性探针,建立了间接测定尼泊金乙酯的分析方法。实验结果表明,制备的分子印迹膜电化学传感器对尼泊金乙酯具有较高的选择性和灵敏度,测定尼泊金乙脂的线性范围为2.5×10-6~1.0×10-5 mol/L,检出限为8.61×10-8 mol/L。     

Au-Pd合金纳米管修饰的尼古丁分子印迹膜传感器的研究

基于Au-Pd合金修饰的玻碳电极为工作电极,采用循环伏安法将邻氨基酚与尼古丁电沉积在工作电极上,制备了尼古丁分子印迹膜传感器。采用差分脉冲伏安法研究尼古丁在尼古丁分子印迹膜传感器上的电化学行为,考察了模板溶解时间、富集时间和溶液pH值对尼古丁测定的影响。在优化实验条件下,尼古丁分子印迹膜传感器的线性范围为1.2×10~(-7)~2.5×10~(-3) mol/L,检出限为4.6×10~(-8) mol/L。用该传感器对吸烟者血液中尼古丁的含量进行检测,结果表明,该传感器具有灵敏度高、线性范围宽、重现性及稳定性好等优点。     

纳米金/石墨烯复合膜修饰电极检测异烟肼EI北大核心CSCD

先采用滴涂法制备了石墨烯修饰电极(GR/GCE),然后采用电化学方法将纳米金沉积于石墨烯表面制备了纳米金/石墨烯复合材料修饰电极(Au NPs/GR/GCE)。研究了异烟肼(isoniazid,INZ)在该Au NPs/GR/GCE上的电化学行为。结果表明,异烟肼在该修饰电极上有良好的电化学响应。在优化条件下,线性扫描伏安法测定异烟肼的线性范围为1.0×10-7~1.0×10-4mol/L,检出限为5.0×10-8mol/L(S/N=3)。用该法测定了异烟肼注射液中异烟肼的含量,结果令人满意。     

介孔碳纳米纤维修饰电极用于黄酮类化合物芦丁的电化学测定

制备了新型的介孔碳纳米纤维修饰热解石墨电极(MCNF/PGE),并将其用于芦丁含量的测定。用循环伏安法、交流阻抗谱法、示差脉冲伏安法研究了该修饰电极膜性能及芦丁在该修饰电极上的电化学行为。结果表明,修饰电极可有效促进探针离子[Fe(CN)6]3-/4-在电极表面的电子传递;芦丁在该修饰电极表面的电化学过程受扩散控制。由于MCNFs大量的石墨边缘缺陷、大比表面积以及介孔结构,与裸电极相比,该修饰电极对芦丁呈现出很高的电催化活性,芦丁阳极峰电流约为裸电极上的18倍。在最佳实验条件下,芦丁的氧化峰电流(Ipa)与其浓度(c)在2.0×10-8～1.2×10-6mol/L范围内呈良好的线性关系,检出限(S/N=3)为5.0×10-9mol/L,线性系数r2=0.999。此外,计算了电荷转移系数(α)、标准速率常数(ks),并推测了芦丁的电化学氧化还原机理。该修饰电极易于制备、可再生,重复性及稳定性良好,可作为一种高灵敏度的电化学传感器应用于芦丁片剂中芦丁的含量测定。     

电聚合分子印迹传感器测定黑茶中芦丁的含量

以芦丁作为模板分子,邻氨基酚为功能单体,在金电极表面循环伏安法电聚合具有选择性识别芦丁的分子印迹膜。以Fe(CN)3-/4-作为探针分子,采用循环伏安法(CV)、差分脉冲伏安法(DPV)、交流阻抗法(EIS)研究了印迹膜的性能、分子印迹效应。优化了测定芦丁含量的条件,芦丁浓度在5.56×10-6~2.22×10-4mol·L-1范围内,其对数与峰电流呈线性关系,线性方程为:I(μA)=9.83 lgc(mol·L-1)+14.63,检出限为1.85×10-6mol·L-1,并比较了传感器对其结构相似化合物的选择性响应,发现传感器对芦丁检测具有良好的选择性。该传感器成功应用于黑茶中芦丁含量的测定。     

纳米金/石墨烯复合膜修饰电极检测异烟肼

先采用滴涂法制备了石墨烯修饰电极(GR/GCE),然后采用电化学方法将纳米金沉积于石墨烯表面制备了纳米金/石墨烯复合材料修饰电极(Au NPs/GR/GCE)。研究了异烟肼(isoniazid,INZ)在该Au NPs/GR/GCE上的电化学行为。结果表明,异烟肼在该修饰电极上有良好的电化学响应。在优化条件下,线性扫描伏安法测定异烟肼的线性范围为1.0×10-7~1.0×10-4mol/L,检出限为5.0×10-8mol/L(S/N=3)。用该法测定了异烟肼注射液中异烟肼的含量,结果令人满意。     

碳纳米管修饰电极分子印迹传感器的制备及其对氧乐果的测定

以氧乐果为模板分子,邻苯二胺为功能单体,在碳纳米管修饰的玻碳电极表面通过电聚合方法制成氧乐果分子印迹聚合物膜,用无水乙醇洗脱后制备出对氧乐果有特异响应的电化学传感器。通过循环伏安法和电化学阻抗法对分子印迹传感器的电化学性能进行表征。以K_3Fe(CN)_6为探针,采用差分脉冲伏安法研究了该分子印迹传感器的分析性能,建立了氧乐果的间接测定方法。结果表明,K_3Fe(CN)_6的相对峰电流与氧乐果浓度在1.0×10~(-7)~2.0×10~(-6)mol/L范围内呈良好的线性关系,检出限为3.6×10~(-8)mol/L。     

基于多壁碳纳米管/纳米铜复合材料的电化学传感器测定槐米中芦丁

以Nafion-多壁碳纳米管(MWNTs)薄膜修饰玻碳电极,采用恒电位法在其表面电沉积纳米Cu,研制了一种新型的芦丁电化学传感器。采用循环伏安法和电化学阻抗谱研究传感器在铁氰化钾-亚铁氰化钾体系中的电化学行为,以考察传感器的电化学性能,采用扫描电镜对传感器表面的形态进行了研究,并利用差分脉冲伏安法测定芦丁的含量。实验结果表明,该传感器对芦丁有较好的催化作用。在优化实验条件下,对芦丁检测的线性范围为1.0×10-8~1.0×10-6 mol/L,检出限为8.4×10-9 mol/L(S/N=3),回收率为98.1%~101%,该传感器制作简单,线性范围宽,灵敏度高,为槐米等样品中芦丁含量的检测提供了一种新的、行之有效的方法。     

A sensitive electrochemical sensor for detection of rutin based on a gold nanocage‐modified electrode

In this article, an electrochemical sensor based on a gold nanocage (AuNC)‐modified carbon ionic liquid electrode (CILE) was fabricated and applied to the sensitive rutin determination. The presence of AuNCs on the electrode surface greatly improved the electrochemical performance of the working electrode due to its specific microstructure and high metal conductivity. Electrochemical behavior of rutin on AuNCs/CILE was studied using cyclic voltammetry and differential pulse voltammetry with the related electrochemical parameters calculated. Under the optimal experimental conditions, the oxidation peak current of rutin and its concentration had good linear relationship in the range from 4.0 × 10^?9 to 7.0 × 10^?4 mol/L with a low detection limit of 1.33 × 10^?9 mol/L (3σ). This fabricated AuNCs/CILE was applied to direct detection of the rutin concentration in drug samples with satisfactory results, showing the real application of AuNCs in the field of chemically modified electrodes.     

Construction of a novel electrochemical sensor based on molecularly imprinted polymers for the selective determination of chlorpyrifos in real samples

We present a novel electrochemical sensor based on an electrode modified with molecularly imprinted polymers for the detection of chlorpyrifos. The modified electrode was constructed by the synthesis of molecularly imprinted polymers by a precipitation method then coated on a glassy carbon electrode. The surface morphology of the modified electrode was characterized by using field‐emission scanning electron microscopy and transmission electron microscopy. The performance of the imprinted sensor was thoroughly investigated by using cyclic voltammetry and differential pulse voltammetry. The imprinted electrochemical sensor displayed high repeatability, stability, and selectivity towards the template molecules. Under the optimal experimental conditions, the peak current response of the imprinted electrochemical sensor was linearly related to the concentration of chlorpyrifos over the range 1 × 10⁻¹⁰–1 × 10⁻⁵ mol/L with a limit of detection of 4.08 × 10⁻⁹ mol/L (signal‐to‐noise ratio = 3). Furthermore, the proposed molecularly imprinted electrochemical sensor was applied to the determination of chlorpyrifos in the complicated matrixes of real samples with satisfactory results. Therefore, the molecularly imprinted polymers based electrochemical sensor might provide a highly selective, rapid, and cost‐effective method for chlorpyrifos determination and related analysis.     

Determination of Oxytetracycline with a Gold Electrode Modified by Chitosan-Multiwalled Carbon Nanotube Multilayer Films and Gold Nanoparticles

A molecularly imprinted electrochemical sensor was fabricated based on a gold electrode modified by chitosan-multiwalled carbon nanotube composite (CS-MWCNTs) multilayer films and gold nanoparticles (AuNPs) for convenient and sensitive determination of oxytetracycline (OTC). The multilayer of CS-MWCNTs composites and AuNPs were used to augment electronic transmission and sensitivity. The molecularly imprinted polymers (MIPs) were synthesized using OTC as the template molecule and o-phenylenediamine (OPD) as the functional monomer. They were modified on a gold electrode by electropolymerization. The electrochemical behavior of OTC at the imprinted sensor was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), and amperometry. The molecularly imprinted sensor showed high selectivity and excellent stability toward OTC. The linear range was from 3.0 × 10^?8 to 8.0 × 10^?5 mol/L, with a limit of detection (LOD) of 2.7 × 10^?8 mol/L (S/N = 3). The developed sensor showed good recovery in spiked samples analysis.     

纳米银/石墨烯修饰电极测定青蒿素

本文建立一种新型的青蒿素传感器。首先,在玻碳电极上滴涂氧化石墨,通过电化学方法将氧化石墨还原为石墨烯,然后,在石墨烯上沉积纳米银得到石墨烯/纳米银修饰电极,它作为检测青蒿素的电化学传感器。用此电极对青蒿素进行测定,并通过循环伏安法、差分脉冲伏安法、交流阻抗法等研究其电化学行为。该修饰电极在测定青蒿素溶液时,表现出较正的还原电位和较大的峰电流等优势;对其实验条件如电解质溶液的p H、应用电势等进行了探查,该电化学传感器在青蒿素溶液浓度范围为1.0×10-8~3.0×10-5mol/L时与其还原峰电流呈现良好的线性关系,最低检出限为1.2×10-9mol/L(S/N=3)。此外,对该传感器的稳定性和重现性等也进行了研究,获得令人满意的结果。     

Development and application of the tartrazine voltammetric sensors based on molecularly imprinted polymers

A modified glassy carbon electrode was prepared as an electrochemical voltammetric sensor based on molecularly imprinted polymer film for tartrazine (TT) detection. The sensitive film was prepared by copolymerization of tartrazine and acrylamide on the carbon nanotube-modified glassy carbon electrode. The performance of the imprinted sensor was investigated by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy in detail. Under the optimum conditions, two dynamic linear ranges of 8?×?10^?8 to 1?×?10^?6?mol?L^?1 and 1?×?10^?6 to 1?×?10^?5?mol?L^?1 were obtained, with a detection limit of 2.74?×?10^?8?mol?L^?1(S/N?=?3). This sensor was used successfully for tartrazine determination in beverages.     

Sol-Gel Imprinted Polymers Based Electrochemical Sensor for Paracetamol Recognition and Detection

Molecular imprinting and sol-gel technique were combined to develop a molecular imprinted polymer (MIP) based electrochemical sensor in this work. With the successive modification of multi-walled carbon nanotubes (MWNTs) and gold nanoparticles (GNPs), a modified glassy carbon electrode (GCE) was immersed in a sol-gel solution in the presence of paracetamol (PR) for the electropolymerization to fabricate an imprinted sensor. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) were employed to characterize the constructed sensor. The factors for the sensor preparation, the electropolymerization potential range, the monomer concentration, and the scan rate for the sensor preparation were optimized. The sensor displayed an excellent recognition capacity toward PR compared with other analogues. Additionally, the DPV peak current was linear to the PR concentration in the range from 8.0 × 10^?8 to 5.0 × 10^?5 mol/L, with a detection limit of 4.0 × 10^?8 mol/L. The prepared sensor also showed satisfactory reproducibility and regeneration capacity.     

利巴韦林原位聚合分子印迹电化学传感器的研制

利用原位聚合分子印迹技术,以3-氨基苯硼酸(3-ABBA)为功能单体,利巴韦林(RIB)为目标分子,以硼酸和顺式二醇在不同酸碱度条件下可逆形成环内酯键为原理,在玻碳电极表面原位聚合形成利巴韦林分子印迹膜,研制了测定利巴韦林的分子印迹电化学传感器。采用循环伏安法(CV)和差分脉冲法(DPV)对印迹膜性能进行研究。DPV测试表明:在最优实验条件下,利巴韦林的浓度在5.0×10~(-8)~1.0×10~(-5)mol/L范围内与峰电流呈良好的线性关系,相关系数(r~2)为0.995 3,检出限(S/N=3)为1.5×10~(-8)mol/L。特异性实验表明制备的传感器对利巴韦林的选择性良好。该分子印迹电化学传感器可用于食品中利巴韦林的检测。     

Selective Electrochemical Determination of Salicylic Acid in Wheat Using Molecular Imprinted Polymers

Salicylic acid is a phytohormone, playing crucial roles in signal transduction, crop growth, and development, and defense to environmental challenges. In this study, a highly selective electrochemical sensor was designed and used to determine salicylic acid using molecularly imprinted polymers for recognition. The electrochemical sensor was fabricated via stepwise modification of gold nanoparticle–graphene–chitosan and molecularly imprinted polymers on a glassy carbon electrode. With electrochemical deposition, a gold nanoparticle–graphene–chitosan film was deposited on the glassy carbon electrode and enhanced the sensitivity. Molecularly imprinted polymers with adsorbed template salicylic acid were added to the surface of the modified electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrodes. Salicylic acid in wheat was quantified by the sensor using the molecularly imprinted polymer/gold nanoparticle–graphene–chitosan/glassy carbon electrode. Concentrations of salicylic acid from 5?×?10^?10 to 5?×?10^?5?mol?L^?1 were determined showing that the developed sensor was suitable for the analysis of food.     

介孔炭/纳米金修饰玻碳电极的制备及其应用研究

制备了介孔炭/纳米金修饰玻碳电极,并对对苯二酚(HQ)在该修饰电极上的电化学行为进行了研究。与HQ在纯介孔炭材料修饰玻碳电极上的电化学响应相比,HQ在该修饰电极上的氧化峰和还原峰电流均大大增加,表明纳米金与介孔炭复合后对HQ具有良好的催化作用。HQ在该修饰电极上经过富集后,峰电流明显增大。采用循环伏安法对HQ电化学行为进行研究,结果表明,HQ在3.0×10-8~1.0×10-6mol/L和1.0×10-6~1.0×10-4mol/L浓度范围内与峰电流呈良好的线性关系,据此建立了检测HQ的电化学分析方法。该方法的相对标准偏差为0.69%,检出限(S/N=3)为1.0×10-8mol/L,具有较高的稳定性和灵敏度。