Commercial screen-printed carbon electrodes have been treated with a CO₂ laser energy of 12.8 mJ cm⁻² in air. This thermal treatment resulted in an increase in the crystallinity of the graphite and an enhancement in electron transfer rates, determined by Raman spectroscopy and cyclic voltammetry, respectively. Laser treatment also facilitated the introduction of oxygen groups by anodization at a potential of 1.55 V vs Ag, which was highly beneficial for the simultaneous detection of dopamine (DA), even in the presence of ascorbic acid (AA), and uric acid (UA) by differential pulse voltammetry (DPV). Anodized laser-treated electrodes were much better at resolving the oxidation peaks of these three substances compared to the as-received commercial electrodes. A linear response from 0.34 to 1.6 µM and a detection limit of 80 nM were obtained for DA in the presence of 20 µM uric acid and 160 µM ascorbic acid. This work demonstrates a suitable method to improve sensitivity in carbon-based printable sensors for the simultaneous analysis of oxygen surface-sensitive substances.

商业丝网印刷碳电极已用12.8 mJ cm ^-2的 CO ₂激光能量处理在空气中。这种热处理导致石墨结晶度的增加和电子转移速率的提高，分别由拉曼光谱和循环伏安法测定。激光处理还通过在 1.55 V vs Ag 的电位下通过阳极氧化促进了氧基团的引入，这对于同时检测多巴胺 (DA) 非常有益，即使在抗坏血酸 (AA) 和尿酸 (UA) 存在的情况下) 通过差分脉冲伏安法 (DPV)。与收到的商用电极相比，阳极化激光处理电极在解析这三种物质的氧化峰方面要好得多。在 20 µM 尿酸和 160 µM 抗坏血酸存在下，DA 的线性响应范围为 0.34 至 1.6 µM，检测限为 80 nM。