Hamnca Siyabulela, Chamier Jessica, Grant Sheila, Glass Timothy, Iwuoha Emmanuel, Baker Priscilla
SensorLab, Chemistry Department, University of the Western Cape, Bellville, South Africa.
HySA Catalysis, Department of Chemical Engineering, University of Cape Town, Rondebosch, Cape Town, South Africa.
Front Chem. 2022 Feb 16;9:782813. doi: 10.3389/fchem.2021.782813. eCollection 2021.
Polyamic acid (PAA) nanofibers produced by using the electrospinning method were fully characterized in terms of morphology and spectroscopy. A PAA nanofiber-modified screen-printed carbon electrode was applied to the detection of selected sulfonamides by following an electroanalytical protocol. The polyamic acid (PAA) nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy to study the integrity of polyamic acid functional groups as nanofibers by comparing them to chemically synthesized polyamic acid. A scanning electron microscope (SEM) was used to confirm the morphology of the produced nanofibers and 3D arrangement at the electrode interface. The Brunauer-Emmett-Teller (BET) method was used to determine the surface area of the nanofibers. Atomic force microscopy (AFM) was used to study the porosity and surface roughness of the nanofibers. Electrochemical evaluation based on diffusion-controlled kinetics was applied to determine the number of electrons transferred in the system, the surface concentration of the deposited PAA thin film (2.14 × 10 mol/cm), and the diffusion coefficient (D) for the PAA nanofiber-modified screen-printed carbon electrode (9.43 × 10 cm/s). The reported LODs for sulfadiazine and sulfamethazine detection are consistent with requirements for trace-level monitoring by early warning diagnostic systems.
采用静电纺丝法制备的聚酰胺酸（PAA）纳米纤维在形态和光谱方面得到了全面表征。通过遵循电分析方案，将聚酰胺酸（PAA）纳米纤维修饰的丝网印刷碳电极应用于选定磺胺类药物的检测。利用傅里叶变换红外（FTIR）光谱对聚酰胺酸（PAA）纳米纤维进行表征，通过与化学合成的聚酰胺酸进行比较，研究聚酰胺酸官能团作为纳米纤维的完整性。使用扫描电子显微镜（SEM）确认所制备纳米纤维的形态以及电极界面处的三维排列。采用布鲁诺尔-埃米特-泰勒（BET）方法测定纳米纤维的表面积。利用原子力显微镜（AFM）研究纳米纤维的孔隙率和表面粗糙度基于扩散控制动力学的电化学评估用于确定系统中转移的电子数、沉积的PAA薄膜的表面浓度（2.14×10 mol/cm）以及PAA纳米纤维修饰的丝网印刷碳电极的扩散系数（D）（9.43×10 cm/s）。所报道的磺胺嘧啶和磺胺二甲嘧啶检测限符合早期预警诊断系统痕量水平监测的要求。
