The variation in biomarkers levels, such as L-methionine, can be an indicator of health problems or diseases, such as metabolism, neuropsychiatric disorders, or some virus infections. Thus, the development of accurate sensors, with low-cost and rapid response has been gaining increasing importance and attractiveness for the early diagnosis of diseases. In this regard, we have proposed a method for L-methionine electrochemical detection using a low-cost and simple arrangement of 3D-printed electrodes (working, reference, and auxiliary electrodes) based on polylactic acid/graphene filament (PLA-G), in which all electrodes were printed. The working electrode was chemically and electrochemically treated, showing a high electroactive area, with graphene edge plans exposure and better electron transfer when compared to the untreated electrode. An excellent analytical performance was obtained with a sensitivity of 0.176 μAL μmol-1, a linear dynamic range of 5.0 μmol L-1- 3000 μmol L-1 and limit of detection of 1.39 μmol L-1. The proposed device was successfully applied for L-methionine detection in spiked serum samples, showing satisfactory recovery values. This indicates the potentiality of the proposed arrangement of electrodes for the L-methionine detection in biological samples at different concentration levels.

中文翻译：

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通过全 3D 打印电极检测生物样品中的 L-蛋氨酸

L-甲硫氨酸等生物标志物水平的变化可能是健康问题或疾病的指标，例如新陈代谢、神经精神疾病或某些病毒感染。因此，开发具有低成本和快速响应的精确传感器对于疾病的早期诊断越来越重要和有吸引力。在这方面，我们提出了一种 L-蛋氨酸电化学检测方法，该方法使用基于聚乳酸/石墨烯长丝 (PLA-G) 的 3D 打印电极（工作电极、参考电极和辅助电极）的低成本和简单排列，其中印刷了所有电极。与未处理的电极相比，工作电极经过化学和电化学处理，显示出高电活性面积，石墨烯边缘平面暴露和更好的电子转移。获得了出色的分析性能，灵敏度为 0.176 μmol L-1，线性动态范围为 5.0 μmol L-1-3000 μmol L-1，检测限为 1.39 μmol L-1。所提出的装置已成功应用于加标血清样品中的 L-蛋氨酸检测，显示出令人满意的回收率值。这表明所提议的电极布置在不同浓度水平的生物样品中检测 L-甲硫氨酸的潜力。