This work describes the preparation of zinc oxide nanoparticles (ZnO NP) from onion extract through a combination of microwave irradiation and muffle furnace in less than 2 h. Characterization with UV-visible, FTIR, and XRD has confirmed successful formation of nanoparticles. TEM analysis displays the nanoparticles to be spherical shaped with an average size of 6.4 nm. The developed ZnO NP film displays good sensing capability of dopamine and had an oxidation potential of + 0.3 V. Under optimized conditions (pH and scan rate), the ZnO NP-GCE is stable even at 500 rpm, showed good linearity in sensing dopamine within the tested range of 3.9-250 µM, has a limit of detection of 3.53 µM and stable electrocatalytic activity even after 30 cycles. The newly developed electrode can distinguish dopamine in a satisfactory way in presence of ascorbic acid and glucose and with 94.9 % of detection in human urine. This study also highlighted the potential of IO Rodeostat (an open source electrochemical workstation) as a feasible option in low resource laboratories to perform sensing studies.

中文翻译：

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洋葱基氧化锌纳米粒子可作为电化学传感器

这项工作描述了在不到2小时的时间内通过微波辐射和马弗炉的组合，从洋葱提取物中制备氧化锌纳米颗粒（ZnO NP）。用紫外可见光，FTIR和XRD进行的表征已证实成功形成了纳米颗粒。TEM分析显示纳米颗粒为球形，平均尺寸为6.4 nm。所开发的ZnO NP膜显示出良好的多巴胺传感能力，氧化电位为+ 0.3V。在优化的条件（pH和扫描速率）下，ZnO NP-GCE甚至在500 rpm时仍稳定，在检测多巴胺的过程中线性良好测试范围为3.9-250 µM，检测极限为3.53 µM，即使经过30个循环后仍具有稳定的电催化活性。新开发的电极可以在存在抗坏血酸和葡萄糖的情况下以令人满意的方式区分多巴胺，并且在人类尿液中的检出率为94.9％。这项研究还强调了IO Rodeostat（开放式电化学工作站）作为低资源实验室中进行传感研究的可行选择的潜力。