Laboratory of Functional Nanostructures, National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania.
NAITEC, C/Tajonar 20, 31006 Pamplona, Spain.
Int J Mol Sci. 2023 Jan 6;24(2):1129. doi: 10.3390/ijms24021129.
Due to the great significance of amino acids, a substantial number of research studies has been directed toward the development of effective and reliable platforms for their evaluation, detection, and identification. In order to support these studies, a new electrochemical platform based on PANI/ZnO nanowires' modified carbon inks screen-printed electrodes was developed for qualitative analysis of electroactive amino acids, with emphasis on tyrosine (Tyr) and tryptophan (Trp). A comparative investigation of the carbon ink before and after modification with the PANI/ZnO was performed by scanning electron microscopy and by Raman spectroscopy, confirming the presence of PANI and ZnO nanowires. Electrochemical investigations by cyclic voltammetry and electrochemical impedance spectroscopy have shown a higher charge-transfer rate constant, which is reflected into lower charge-transfer resistance and higher capacitance values for the PANI/ZnO modified ink when compared to the simple carbon screen-printed electrode. In order to demonstrate the electrochemical performances of the PANI/ZnO nanowires' modified carbon inks screen-printed electrodes for amino acids analysis, differential pulse voltammograms were obtained in individual and mixed solutions of electroactive amino acids. It has been shown that the PANI/ZnO nanowires' modified carbon inks screen-printed electrodes allowed for tyrosine and tryptophan a peak separation of more than 100 mV, enabling their screening and identification in mixed solutions, which is essential for the electrochemical analysis of proteins within the proteomics research field.
由于氨基酸的重要意义，大量的研究致力于开发有效和可靠的平台来评估、检测和鉴定它们。为了支持这些研究，开发了一种新的基于 PANI/ZnO 纳米线修饰碳油墨丝网印刷电极的电化学平台，用于电活性氨基酸（重点是酪氨酸 (Tyr) 和色氨酸 (Trp)）的定性分析。通过扫描电子显微镜和拉曼光谱对修饰前后的碳油墨进行了比较研究，证实了 PANI 和 ZnO 纳米线的存在。通过循环伏安法和电化学阻抗谱的电化学研究表明，与简单的碳丝网印刷电极相比，PANI/ZnO 修饰油墨具有更高的电荷转移速率常数，这反映为电荷转移电阻更低和电容值更高。为了证明 PANI/ZnO 纳米线修饰碳油墨丝网印刷电极在氨基酸分析中的电化学性能，在单独和混合的电活性氨基酸溶液中获得了差分脉冲伏安图。结果表明，PANI/ZnO 纳米线修饰碳油墨丝网印刷电极允许酪氨酸和色氨酸的峰分离超过 100 mV，使其能够在混合溶液中进行筛选和鉴定，这对于蛋白质组学研究领域中蛋白质的电化学分析至关重要。
