Baranowska-Korczyc Anna, Maksymiuk Krzysztof, Michalska Agata
Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
Analyst. 2019 Aug 7;144(15):4667-4676. doi: 10.1039/c9an00756c. Epub 2019 Jul 2.
A novel type of optode sensor is proposed using electrospun nanofibers as the supporting inert material. The proposed arrangement offers the possibility of a significant extension of the surface area of the probe while also minimizing the thickness of the receptor layer. This novel, close to 2D, optode configuration results in a sensor free from limitations related to analyte transport in the receptor phase. Unlike other formats, low analyte ion concentrations (10-10 M) were recorded, which are typically inaccessible for other formats of optodes, with a linear dependence of the emission signal on the logarithm of the analyte concentration. This effect results from a significant exhaustion of the analyte in the sample close to the interface with the sensor. On the other hand, as the ionophore surface concentration in the receptor was close to saturation, for a high concentration of the analyte (>10 M) in solution, the optode responses were observed with a sigmoidal dependence of the emission intensity on the logarithm of analyte concentration, independent of the applied ionophore contents in the 2D receptor phase. It was also shown that the response of the nanofiber supported liquid optode layer is reversible for the sigmoidal response range.
提出了一种新型的光极传感器，它使用电纺纳米纤维作为支撑惰性材料。所提出的结构提供了显著扩展探头表面积的可能性，同时还能使受体层的厚度最小化。这种新型的、接近二维的光极配置使得传感器不受受体相中分析物传输相关限制的影响。与其他形式不同，该传感器记录到了低分析物离子浓度（10-10 M），而其他形式的光极通常无法检测到如此低的浓度，且发射信号与分析物浓度的对数呈线性关系。这种效应是由于靠近传感器界面的样品中分析物大量耗尽所致。另一方面，由于受体中离子载体的表面浓度接近饱和，对于溶液中高浓度的分析物（>10 M），观察到光极响应，其发射强度与分析物浓度的对数呈S形依赖关系，与二维受体相中所施加的离子载体含量无关。还表明，纳米纤维支撑的液体光极层在S形响应范围内的响应是可逆的。
