Hangzhou Dianzi University, College of Automation, Hangzhou 310018, China.
Jiaxing University, College of Biological, Chemical Science, and Engineering, Jiaxing, Zhejiang, 314001, China.
J AOAC Int. 2021 Mar 5;104(1):157-164. doi: 10.1093/jaoacint/qsaa089.
Nitrite is naturally present in vegetables and added to processed meats to enhance their color and prolong their shelf life. It is of concern because it reacts to form nitrosamines, which have been linked to cancer.
To develop a quick, reliable, and inexpensive method for quantifying nitrite in foods.
A copper-based metal organic framework (Cu-MOF)/gold-platinum alloy nanoparticle(Au@Pt)-modified glassy carbon electrode (GCE) was developed via a simple wet chemical synthesis followed by electrochemical deposition of gold-platinum alloy nanoparticles onto the surface of a GCE. Morphological characterization and component analysis of the prepared nanomaterials were carried out by Fourier transform infrared spectroscopy and scanning electron microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical behavior of the fabricated electrodes.
The quantitative and specific detection of nitrite was obtained by the amperometric i-t method. At a pH of 7, temperature of 25°C, and ionic strength of 0.4 M, the electrode exhibited a linear range of 0.001-12.2 mM nitrite with a low detection limit of 72 nM (S/N = 3).
The Cu-MOF/Au@Pt/GCE exhibited good repeatability, reproducibility, stability, and selectivity to provide a capable analysis method for food samples.
A Cu-MOF with a large surface area and high porosity was developed to provide an electrode with many active sites. The Au@Pt alloy nanoparticle improved the electrocatalytic activity toward nitrite. The synergistic action between the Cu-MOF and Au@Pt alloy nanoparticle enhanced the electrochemical performance of the sensor.
亚硝酸盐天然存在于蔬菜中,并被添加到加工肉类中以增强其颜色并延长其保质期。由于它会与其他物质反应形成亚硝胺,而亚硝胺与癌症有关,所以引起了人们的关注。
开发一种快速、可靠且廉价的方法来定量检测食品中的亚硝酸盐。
通过简单的湿化学合成,制备了一种基于铜的金属有机骨架(Cu-MOF)/金-铂合金纳米粒子(Au@Pt)修饰的玻碳电极(GCE),然后通过电化学沉积将金-铂合金纳米粒子沉积到 GCE 的表面。通过傅里叶变换红外光谱和扫描电子显微镜对制备的纳米材料进行形貌表征和成分分析。通过循环伏安法和电化学阻抗谱研究了制备电极的电化学行为。
通过安培电流法实现了对亚硝酸盐的定量和特异性检测。在 pH 值为 7、温度为 25°C 和离子强度为 0.4 M 的条件下,电极对 0.001-12.2 mM 的亚硝酸盐表现出线性范围,检测限低至 72 nM(S/N = 3)。
Cu-MOF/Au@Pt/GCE 具有良好的重复性、重现性、稳定性和选择性,为食品样品提供了一种可行的分析方法。
开发了具有大表面积和高孔隙率的 Cu-MOF,为电极提供了许多活性位点。Au@Pt 合金纳米粒子提高了对亚硝酸盐的电催化活性。Cu-MOF 和 Au@Pt 合金纳米粒子的协同作用增强了传感器的电化学性能。