Electroactive biofilm has a low tolerance for accidental shocks, such as extreme acid shock, which is a potential limitation for the application of bioelectrochemical systems (BESs), especially as a sensor for water quality monitoring. In this work, we encapsulated electroactive biofilms with biocompatible polydopamine (PDA) to protect against extreme acid shock. The bacterial cells were completely encapsulated in ∼50 nm films formed by PDA spheres, which protected their viability and current recoverability even after pH 0.5 and 1.5 shocks. The limiting current density of the PDA-encapsulated anode was 0.20 ± 0.05 A/m², which was 1900% higher than that of the unprotected control (0.01 ± 0.01 A/m²) after strong acid shock (pH 0.5, 30 min). Without PDA encapsulation, the biofilm partly disintegrated with a thickness decreased by 68% from 72 to 23 μm, where 92% of the cells were dead. Our findings reported a novel and effective method for protecting electroactive biofilm under extreme conditions, which will greatly extend the use of BESs in the future.

中文翻译：

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聚多巴胺封装保护电活性生物膜免受极端酸冲击

电活性生物膜对意外冲击（例如极端酸冲击）的耐受性较低，这对生物电化学系统（BES）的应用（尤其是作为水质监测传感器）的应用存在潜在的限制。在这项工作中，我们用生物相容性聚多巴胺（PDA）封装了电活性生物膜，以保护其免受极端酸冲击。细菌细胞被完全封装在PDA球形成的〜50 nm薄膜中，即使在pH 0.5和1.5的电击后，它们也能保护其生存能力和电流恢复能力。PDA封装的阳极的极限电流密度为0.20±0.05 A / m ²，比未保护的对照的极限电流密度（0.01±0.01 A / m ^2）高1900％）在强酸冲击下（pH 0.5，30分钟）。没有PDA封装，生物膜部分分解，厚度从72微米降低到23微米，降低了68％，其中92％的细胞死亡。我们的发现报告了一种在极端条件下保护电活性生物膜的新颖有效的方法，它将在未来极大地扩展BES的使用。