The electrochemical method is the most effective, facile, and economical approach for the detection of small molecules. The present article deals with the design and engineering of polymer–graphene-based thin films through an in situ facile synthesis technique for the development of high performance electrochemical sensors. We report a facile technique for preparing polyaniline (PANI) and polyaniline/graphene (PANI/G) nanocomposite thin films and their application as enzyme-free electrochemical sensors for hydrogen peroxide (H₂O₂). PANI and PANI/G films were deposited on a dopamine modified ITO substrate via spin coating and in situ deposition techniques. The in situ fabricated films, which exhibited better electrical properties and stability as compared to the spin coated films, were studied in detail. These thin films were characterized using UV-visible spectroscopy, FT-IR spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM) to study their optical, chemical, and surface textural properties. Results show a homogeneous distribution of the constituting materials. From the AFM results, it was found out that the PANI/G film showed increased surface roughness (∼20 nm) as compared to the PANI film (∼15 nm). The electrochemical properties of the films were determined using the van der Pauw method and cyclic voltammetry technique. The conductivity of the PANI and PANI/G films was estimated to be 5.38 × 10³ and 6.84 × 10³ S cm⁻¹, respectively. Finally, the electrochemical sensing performances of the PANI and PANI/G films were investigated towards H₂O₂ reduction in a wide potential range of −0.6 to 0.6 V in 0.1 M PBS solution of pH 7.0. This work demonstrates the application of thin-film technology for the development of nanodevice sensors.

中文翻译：

---

一种用于过氧化氢无酶电化学传感的新型聚苯胺/石墨烯纳米复合薄膜的简便合成

电化学方法是检测小分子的最有效、最简便、最经济的方法。本文通过原位简易合成技术处理聚合物-石墨烯基薄膜的设计和工程，以开发高性能电化学传感器。我们报告了一种用于制备聚苯胺 (PANI) 和聚苯胺/石墨烯 (PANI/G) 纳米复合薄膜的简便技术及其作为过氧化氢 (H ₂ O ₂ )无酶电化学传感器的应用。PANI 和 PANI/G 薄膜通过旋涂和原位沉积技术沉积在多巴胺改性的 ITO 基板上。在原位详细研究了制造的薄膜，与旋涂薄膜相比，它表现出更好的电性能和稳定性。使用紫外-可见光谱、FT-IR 光谱、拉曼光谱、扫描电子显微镜 (SEM) 和原子力显微镜 (AFM) 对这些薄膜进行表征，以研究它们的光学、化学和表面结构特性。结果显示构成材料的均匀分布。从 AFM 结果中发现，与 PANI 膜（~15 nm）相比，PANI/G 膜显示出增加的表面粗糙度（~20 nm）。使用范德堡法和循环伏安法测定薄膜的电化学性能。PANI 和 PANI/G 薄膜的电导率估计为 5.38 × 10 ³和 6.84 × 10分别为³ S cm ^-1。最后，研究了 PANI 和 PANI/G 薄膜在 pH 7.0 的 0.1 M PBS 溶液中在 -0.6 至 0.6 V 的宽电位范围内对 H ₂ O ₂还原的电化学传感性能。这项工作展示了薄膜技术在纳米器件传感器开发中的应用。