Here we investigated the electrochemical properties and dopamine (DA) detection capability of SU-8 photoresist based pyrolytic carbon (PyC) as well as its biocompatibility with neural cells. This approach is compatible with microfabrication techniques which is crucial for device development. X-ray photoelectron spectroscopy shows that PyC consists 98.5% of carbon, while oxygen plasma treatment (PyC-O₂) increases the amount of oxygen up to 27.1%. PyC showed nearly reversible (ΔE_p 63 mV) electron transfer kinetics towards outer sphere redox probe (Ru(NH₃)₆^2+/3+), while the reaction on PyC-O₂ was quasi-reversible (ΔE_p > 75 mV). DA showed both diffusion and adsorption-defined reaction kinetics with fast electron transfer with the ΔE_p values of 50 mV and 30 mV, for PyC and PyC-O₂, respectively. The strong interaction between the hydroxyl groups on the surface and DA, as confirmed by simulations, facilitates the redox reactions of DA. DA showed a linear response in the measured physiologically relevant range (50 nM–1 μM) and sensitivities were 1.2 A M⁻¹ cm⁻² for PyC and 2.7 A M⁻¹ cm⁻² for PyC-O₂. Plasma oxidation (PyC-O₂) improved cell adhesion even more than poly-L-lysine (PLL) coating on PyC, but best adhesion was achieved on PLL coated PyC-O₂. Glial cells, neuroblastoma cells and neural stem cells all showed similar behavior.

中文翻译：

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基于SU-8的热解碳用于多巴胺的电化学检测

在这里，我们研究了基于SU-8光刻胶的热解碳（PyC）的电化学性质和多巴胺（DA）检测能力，以及其与神经细胞的生物相容性。这种方法与对设备开发至关重要的微细加工技术兼容。X射线光电子能谱显示PyC包含98.5％的碳，而氧等离子体处理（PyC-O ₂）可将氧气量增加至27.1％。PyC向外球氧化还原探针（Ru（NH ₃）₆ ^{2 + / 3 +}）表现出几乎可逆的（ΔE _p 63 mV）电子转移动力学，而在PyC-O ₂上的反应是准可逆的（ΔE _p> 75 mV）。DA显示出PyC和PyC-O _2的扩散和吸附定义的反应动力学以及快速的电子转移，其ΔE _p值分别为50 mV和30 mV 。通过模拟证实，表面羟基与DA之间的强相互作用促进了DA的氧化还原反应。DA在所测量的生理相关范围（50 nM–1μM）中显示线性响应，对PyC的敏感性为1.2 AM ^-1 cm ^-2，对PyC-O _2的敏感性为2.7 AM ^-1 cm ^-2。血浆氧化（PyC-O ₂）甚至比聚L改善了细胞粘附-赖氨酸（PLL）涂层在PyC上，但是在PLL涂层的PyC-O ₂上实现了最佳粘合。胶质细胞，神经母细胞瘤细胞和神经干细胞均表现出相似的行为。