基于Ni12P5纳米粒子的电化学传感器用于灵敏测定葡萄糖

通过改进的热溶剂胶体合成法制备了单分散的Ni₁₂P₅纳米粒子,并利用X射线衍射、透射电子显微镜、X射线光电子能谱、X射线能谱对Ni₁₂P₅纳米粒子的晶体结构、化学组成和形貌等进行了表征。基于单分散Ni₁₂P₅纳米粒子研制出的非酶葡萄糖传感器具有出色的性能,其快速响应时间小于3 s,检测范围广（0.002~4.2 mmol·L^-1）,灵敏度高达1 572 mA·L·mol^-1·cm^-2,检测限低至0.8 μmol·L^-1。此外,该传感器在用于人体血液中葡萄糖的实际检测中取得了满意的效果。     

Electroanalytical Determination of Estrone in Seawater Samples Using Functionalized Multiwalled Carbon Nanotubes

In this work, a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes functionalized with carboxylic groups (MWCNT−COOH) was used to determine the hormone estrone in seawater samples. Modification of the electrode was optimized using three successive 10-μL aliquots of the MWCNT−COOH dispersion in ethanol (1 : 5 mL). The cyclic voltammetry results showed an oxidation peak at 0.59 V with characteristics of an irreversible process, pH dependent and controlled by adsorption of species. The results of square-wave voltammetry showed that the intensities of peak currents for the MWCNT−COOH/GCE were about 2.5 times higher than for GCE. The calibration curve showed a linearity of 0.9981 and a sensitivity of 0.1521 μA/mol L⁻¹. The limits of detection and quantification were 0.117 and 0.392 μmol L⁻¹, respectively. The recovery obtained using seawater samples was 91%, indicating the applicability of the method in marine environments.     

Disposable and Flexible Electrochemical Paper-based Analytical Devices Using Low-cost Conductive Ink

In this work, a simple procedure for construction of disposable electrochemical paper-based analytical devices (ePADs) by screen-printing using low-cost materials and a home craft electronic printer is proposed. The devices were constructed using liner paper as a substrate and carbon ink prepared with graphite powder and wood glue. The ePAD was evaluated as an electrochemical sensor and biosensor. The proposed conductive carbon-based ink can be easily prepared and is an eco-friendly and non-toxic material. The developed ePAD was simple to produce and can be used as a low-cost electrochemical sensor, at less than US $0.20 per device.     

纳米金-二氧化钛纳米针修饰电极用于氯霉素检测

将金胶-TiO2纳米针修饰玻碳(Au-TiO2/GC)电极用于对氯霉素(CAP)浓度的电化学测定。 结果表明,在0.1 mol/L pH=7.0的磷酸盐缓冲溶液(PBS)体系中,CAP在Au-TiO2/GC电极上有较好的电化学响应,CAP浓度在8.0×10-7～1.0×10-4 mol/L范围内,峰电流与其浓度呈良好的线性关系,检出限为7.8×10-8 mol/L。 并对氯霉素滴眼液中CAP浓度进行了检测,发现该方法有高的检测灵敏度、好的重复性和抗干扰性,且操作简便、成本低廉。     

Determination of Ni with Electrodes Modified with Mordant Violet 5

Abstract

The utility of electrodes modified with the dye Mordant Violet 5 (MV-5) for the determination of Ni is demonstrated. The method is based on the coordination of Ni from solution by an immobilized layer (via ion exchange) of the dye. Upon coordination the redox response of the dye is shifted in the negative direction by about 250 mV (from ?0.74 to ?0.97 V). The height of this peak is used as the analytical signal which is related to the concentration of Ni in solution. Linear calibration curves were obtained for Ni concentrations ranging from about 10^?4 to 2×10^?3M. Although this reflects only moderate sensitivity, a basic concept is established; this method allows for the determination of the metal via the redox response of the dye. Thus, with appropriate choice of reagents, metal ions difficult to determine by direct reduction can be determined by this method. The use of other reagents may result in enhanced sensitivity.     

Development of a voltammetric method of analysis using praseodymium oxide-carbon nanotubes for the sensitive detection of dopamine in the presence of tramadol,paracetamol and ascorbic acid

A sensitive and selective method of analysis was constructed by the the combination of praseodymium oxide and carbon nanotubes. The charge transfer resistance (Rct) values of 109 in 1 × 10⁻³ M K₃[Fe(CN)₆] and 79 Ω in 5 × 10⁻⁶ M dopamine indicate that Pr₆O₁₁@MWCNTs/GCE enables an excellent electron pathway between electrolyte and electrode. The platform was successfully applied for the determination of dopamine in the presence of tramadol, paracetamol and ascorbic acid. The platform exhibited a remarkable decrease in ▵Ep for DA. A dynamic linear range from 1.2 × 10⁻⁹ M to 1.8 × 10⁻⁵ M was obtained with an LOD of 1.0 × 10⁻¹⁰ M. Such a sensitive and selective method of analysis makes Pr₆O₁₁@MWCNTs/GCE of high interest to observe trace level of DA with good accuracy and precision.