Department of Chemistry, Faculty of Science, Srinakharinwirot University, Sukhumvit 23, Bangkok, 10110, Wattana, Thailand.
Mikrochim Acta. 2023 Sep 18;190(10):398. doi: 10.1007/s00604-023-05970-1.
Discovering alternative analytical techniques is crucial for practical applications; thus, this work aims to develop an innovative and simple electrochemical sensor for melanoma and the clinical diagnosis of related disorders by the simultaneous determination of 3,4-dihydroxy-L-phenylalanine (L-DOPA) and L-tyrosine (L-Tyr). The fabrication is based on the layer-by-layer electrodeposition of poly L-proline (poly(L-pro)) and nanodiamond (ND) onto a screen-printed graphene electrode (SPGE). The poly(L-pro)/ND/SPGEs were morphologically characterized by scanning electron microscopy, energy-dispersive X-ray spectrometry, and Raman spectroscopy followed by electrochemical investigation using cyclic voltammetry, differential pulse voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. These modifier-based electrodes pave a feasible way to unlock the coexisting interfering substances from screen-printing ink composition and improve the sensitivity. Additionally, computational chemistry calculations were performed to fully comprehend the sensing behavior on both target analytes. Under optimal conditions, the developed sensor provided linear concentration ranges of 0.075-50 μM, with a detection limit of 0.021 μM for L-DOPA, and 2.5-120 μM with a detection limit of 0.74 μM for L-Tyr. To demonstrate the reliability of the poly(L-pro)/ND/SPGE in practical application, it was successfully applied to the determination of these analytes in human urine and blood serum samples, with satisfactory recovery ranges (81.73-110.62% for L-DOPA and 82.17-110.01% for L-Tyr) and relative standard deviations (0.69-9.90% for L-DOPA and 0.40-9.55% for L-Tyr). Due to its simplicity, long-term stability (> 87.8% of their initial currents after 35 days), and portability, the developed sensor is a promising alternative analytical method for on-site clinical monitoring.
发现替代分析技术对于实际应用至关重要；因此，本工作旨在通过同时测定 3,4-二羟基-L-苯丙氨酸（L-DOPA）和 L-酪氨酸（L-Tyr），开发一种用于黑色素瘤和相关疾病临床诊断的创新和简单电化学传感器。该制备方法基于将聚 L-脯氨酸（poly(L-pro)) 和纳米金刚石（ND）逐层电沉积在丝网印刷石墨烯电极（SPGE）上。通过扫描电子显微镜、能量色散 X 射线光谱和拉曼光谱对 poly(L-pro)/ND/SPGE 进行形态表征，然后通过循环伏安法、差分脉冲伏安法、计时安培法和电化学阻抗谱进行电化学研究。这些基于修饰剂的电极为从丝网印刷油墨成分中解锁共存的干扰物质并提高灵敏度铺平了可行的道路。此外，还进行了计算化学计算，以充分理解对两种目标分析物的传感行为。在最佳条件下，开发的传感器提供了 0.075-50 μM 的线性浓度范围，L-DOPA 的检测限为 0.021 μM，L-Tyr 的检测限为 2.5-120 μM，检测限为 0.74 μM。为了证明 poly(L-pro)/ND/SPGE 在实际应用中的可靠性，它成功地应用于人尿液和血清样本中这些分析物的测定，回收率范围令人满意（L-DOPA 为 81.73-110.62%，L-Tyr 为 82.17-110.01%），相对标准偏差（L-DOPA 为 0.69-9.90%，L-Tyr 为 0.40-9.55%）。由于其简单性、长期稳定性（>35 天后初始电流的 87.8%）和便携性，开发的传感器是现场临床监测的一种有前途的替代分析方法。
