Abstract The modification of polysulfone (PSF) with multi-walled carbon nanotubes (MWCNT) is presented as a platform for the development of a tyrosinase biosensor. PSF, dissolved in dichloromethane, was deposited on a glassy carbon electrode (GCE), after which MWCNT functionalized in nitric acid, was drop coated on the PSF layer. Tyrosinase enzyme (TyOx), crosslinked with glutaraldehyde, was subsequently deposited on the MWCNT/PSF/GCE transducer to constitute the tyrosinase biosensor. The MWCNT/PSF/GCE (sensor) and TyOx/MWCNT/PSF/GCE (biosensor) were characterized using cyclic voltammetry and electrochemical impedance spectroscopy. Scanning electron microscopy was used to study the morphological changes after each modification step. Cyclic voltammetry measurements confirmed that MWCNT/PSF/GCE was a better platform for the direct detection of tyrosine than MWCNT/GCE or PSF/GCE. A well-defined analytical peak at 0.79 V with respect to Ag/AgCl was observed that was clearly distinguishable from the background current. The tyrosinase biosensor showed a very low limit of detection (0.3 nM) and a very high sensitivity (1.988 µA µM−1 cm−2) towards tyrosine detection compared to comparable devices reported in the literature.

中文翻译：

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使用新型酪氨酸酶多壁碳纳米管 (MWCNT) 聚砜改性玻璃碳电极 (GCE) 电化学测定酪氨酸

摘要 聚砜 (PSF) 与多壁碳纳米管 (MWCNT) 的改性被提出作为开发酪氨酸酶生物传感器的平台。溶解在二氯甲烷中的 PSF 沉积在玻璃碳电极 (GCE) 上，然后将在硝酸中官能化的 MWCNT 滴涂在 PSF 层上。与戊二醛交联的酪氨酸酶 (TyOx) 随后沉积在 MWCNT/PSF/GCE 换能器上以构成酪氨酸酶生物传感器。MWCNT/PSF/GCE（传感器）和 TyOx/MWCNT/PSF/GCE（生物传感器）使用循环伏安法和电化学阻抗谱进行表征。扫描电子显微镜用于研究每个修饰步骤后的形态变化。循环伏安测量证实，MWCNT/PSF/GCE 是比 MWCNT/GCE 或 PSF/GCE 更好的直接检测酪氨酸的平台。在 0.79 V 处观察到一个明确的分析峰，该峰与背景电流明显不同。与文献中报道的类似设备相比，酪氨酸酶生物传感器对酪氨酸检测显示出非常低的检测限 (0.3 nM) 和非常高的灵敏度 (1.988 µA µM-1 cm-2)。