Tsekeli Tebogo R, Sebokolodi Tsholofelo I, Karimi-Maleh Hassan, Arotiba Omotayo A
Department of Chemical Sciences, University of Johannesburg, Doornfontein, Johannesburg 2028, South Africa.
University of Electronic Science and Technology of China, Chengdu 611731, China.
ACS Omega. 2021 Apr 2;6(14):9401-9409. doi: 10.1021/acsomega.0c05836. eCollection 2021 Apr 13.
Silver nanoparticles (AgNPs) were synthesized separately and loaded onto the expanded layers of exfoliated graphite (EG) to form a silver nanoparticle-exfoliated graphite nanocomposite (AgNPs-EG). The AgNPs-EG was compressed into a pellet (0.6 cm in diameter) and used to prepare an electrochemical sensor for bisphenol A (BPA) in standard samples and in thermal paper. The synthesized materials were characterized by ultraviolet-visible spectrophotometry, X-ray diffraction spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. The electrochemical behavior of BPA on the AgNPs-EG sensor was investigated by cyclic voltammetry and square wave voltammetry. Under optimized experimental conditions, the oxidation peak current was linearly proportional to bisphenol A concentrations in the range from 5.0 to100 μM, with a coefficient of determination ( ) of 0.9981. The obtained limit of detection of the method was 0.23 μM. The fabricated sensor was able to overcome electrode fouling with good reproducibility (RSD = 2.62%, = 5) by mechanical polishing of the electrode on emery paper. The proposed method was successfully applied to determine bisphenol A in thermal paper samples and demonstrated good accuracy of 93.1 to 113% recovery.
分别合成银纳米颗粒（AgNPs）并将其负载到膨胀石墨（EG）的膨胀层上，以形成银纳米颗粒-膨胀石墨纳米复合材料（AgNPs-EG）。将AgNPs-EG压制成直径为0.6厘米的小球，并用于制备用于检测标准样品和热敏纸中双酚A（BPA）的电化学传感器。通过紫外可见分光光度法、X射线衍射光谱法、扫描电子显微镜和能量色散X射线对合成材料进行表征。通过循环伏安法和方波伏安法研究了BPA在AgNPs-EG传感器上的电化学行为。在优化的实验条件下，氧化峰电流与双酚A浓度在5.0至100μM范围内呈线性比例关系，测定系数（ ）为0.9981。该方法获得的检测限为0.23μM。通过在砂纸上对电极进行机械抛光，所制备的传感器能够克服电极污染，具有良好的重现性（RSD = 2.62%， = 5）。所提出的方法成功应用于测定热敏纸样品中的双酚A，回收率在93.1%至113%之间，显示出良好的准确性。
