Sensor Electronic & Instrumentation Group, Department of Physics, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P. 11201, Zitoune, Meknes, Morocco; Biotechnology Agroalimentary and Biomedical Analysis Group, Department of Biology, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P. 11201, Zitoune, 50003, Meknes, Morocco.
Biotechnology Agroalimentary and Biomedical Analysis Group, Department of Biology, Faculty of Sciences, Moulay Ismaïl University of Meknes, B.P. 11201, Zitoune, 50003, Meknes, Morocco.
Talanta. 2020 Mar 1;209:120577. doi: 10.1016/j.talanta.2019.120577. Epub 2019 Nov 21.
Human Exhaled Breath Condensate (EBC) contains markers of several inflammatory diseases. Its analysis is of interest to a number of researchers. Nitrite ions (NO-), which are widely used in our daily lives, are nevertheless among these indicators. In this study, a simple, fast, portable, non-invasive and cheap electrochemical sensor is developed for the analysis of the nitrite profile in EBC. In this regard, sodium nitrite (NaNO) was first immobilized on self-assembled 2-aminothiophenol (2-ATP) on a screen-printed gold electrode (Au-SPE). Then, a polymer matrix composed of polyvinyl alcohol (PVA) crosslinked with glutaraldehyde (GA) was combined with gold nanoparticles (Au-NPs) to cover the modified Au-SPE and complete the fabrication of the Ion Imprinted Polymer (IIP) sensor. The electrochemical behaviour of the sensor was monitored using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) methods, while the morphology and chemical composition of its layers were observed by infrared Fourier transform (FTIR), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy coupled with energy dispersion X-Ray spectroscopy (SEM-EDS) techniques. In addition, after a successful control test using a Non-Imprinted Ion Polymer (NIIP) sensor, the obtained results demonstrated satisfactory sensitivity and selectivity to nitrite compared to co-existing interfering substances in EBC, such as nitrate, acetate and ammonium nitrate. Under improved experimental conditions, the nitrite IIP sensor exhibits responses proportional to nitrite concentrations (R = 0.96) over a concentration range of 0.5-50 μg mL with a detection limit (LOD) of 4 μmol L (signal-to-noise ratio S/N = 3). The proposed approach was well applied for the nitrite determination in EBC samples with a relative standard deviation (RSD = 4%) and could open clinical applications in respiratory medicine.
人体呼出气冷凝物（EBC）中含有多种炎症性疾病的标志物。其分析引起了许多研究人员的兴趣。亚硝酸盐离子（NO-）广泛应用于我们的日常生活中，但它也是这些指标之一。在这项研究中，开发了一种简单、快速、便携、非侵入性和廉价的电化学传感器，用于分析 EBC 中亚硝酸盐的分布。为此，首先将亚硝酸钠（NaNO）固定在自组装的 2-氨基噻吩（2-ATP）上，然后将其固定在丝网印刷金电极（Au-SPE）上。然后，将由戊二醛（GA）交联的聚乙烯醇（PVA）组成的聚合物基质与金纳米颗粒（Au-NPs）结合，覆盖修饰后的 Au-SPE 并完成离子印迹聚合物（IIP）传感器的制备。通过循环伏安法（CV）、电化学阻抗谱（EIS）和差分脉冲伏安法（DPV）监测传感器的电化学行为，同时通过红外傅里叶变换（FTIR）、原子力显微镜（AFM）和扫描电子显微镜结合能色散 X 射线光谱（SEM-EDS）技术观察其层的形貌和化学成分。此外，在使用非印迹离子聚合物（NIIP）传感器成功进行控制测试后，与 EBC 中共存的干扰物质（如硝酸盐、乙酸盐和硝酸铵）相比，获得的结果表明该传感器对亚硝酸盐具有令人满意的灵敏度和选择性。在改进的实验条件下，亚硝酸盐 IIP 传感器对 0.5-50μg·mL范围内的亚硝酸盐浓度呈比例响应，检测限（LOD）为 4μmol·L（信噪比 S/N=3）。该方法已成功应用于 EBC 样品中亚硝酸盐的测定，相对标准偏差（RSD=4%），有望在呼吸医学中得到临床应用。
