Surface-coated poly(catecholamine) (pCA) films have attracted attention as biomaterial interfaces owing to their biocompatible and physicochemical characteristics. In this paper, we report that pCA-film-coated electrodes are useful for potentiometric biosensing devices. Four different types of pCA film, l-dopa, dopamine, norepinephrine, and epinephrine, with thicknesses in the range of 7–27 nm were electropolymerized by oxidation on Au electrodes by using cyclic voltammetry. By using the pCA-film electrodes, the pH responsivities were found to be 39.3–47.7 mV/pH within the pH range of 1.68 to 10.01 on the basis of the equilibrium reaction with hydrogen ions and the functional groups of the pCAs. The pCA films suppressed nonspecific signals generated by other ions (Na⁺, K⁺, Ca²⁺) and proteins such as albumin. Thus, the pCA-film electrodes can be used in pH-sensitive and pH-selective biosensors. HeLa cells were cultivated on the surface of the pCA-film electrodes to monitor cellular activities. The surface potential of the pCA-film electrodes changed markedly because of cellular activity; therefore, the change in the hydrogen ion concentration around the cell/pCA-film interface could be monitored in real time. This was caused by carbon dioxide or lactic acid that is generated by cellular respiration and dissolves in the culture medium, resulting in the change of hydrogen concentration. pCA-film electrodes are suitable for use in biocompatible and pH-responsive biosensors, enabling the more selective detection of biological phenomena.

中文翻译：

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生物相容性聚（儿茶酚胺）-膜电极，用于电位细胞传感。

由于生物相容性和理化特性，表面涂层聚（儿茶酚胺）（pCA）薄膜作为生物材料界面备受关注。在本文中，我们报告说pCA膜涂覆的电极可用于电位生物传感设备。通过使用循环伏安法在Au电极上进行氧化，将厚度在7–27 nm范围内的四种不同类型的pCA膜（1-多巴，多巴胺，去甲肾上腺素和肾上腺素）进行电聚合。通过使用pCA膜电极，基于与氢离子和pCA官能团的平衡反应，在1.68至10.01的pH范围内发现pH响应为39.3–47.7 mV / pH。pCA膜可抑制其他离子（Na ⁺，K ⁺，Ca ²⁺）和蛋白质（例如白蛋白）。因此，pCA膜电极可用于pH敏感和pH选择性生物传感器。将HeLa细胞培养在pCA膜电极的表面上，以监测细胞活动。pCA膜电极的表面电势由于细胞活性而发生了显着变化。因此，可以实时监测细胞/ pCA-膜界面周围氢离子浓度的变化。这是由细胞呼吸产生的二氧化碳或乳酸引起的，并溶解在培养基中，导致氢浓度的变化。pCA膜电极适用于生物相容性和pH值敏感的生物传感器，从而能够更选择性地检测生物现象。