The operational stability, power efficiency, and technical simplicity of enzymatic biofuel cells are the focus area of research for practical applications of this green energy-generating device. Here, we report some critical findings on these issues on a methanol-fuelled pure biofuel cell fabricated by using alcohol oxidase and bilirubin oxidase as anodic and cathodic catalysts, respectively. The cell was fabricated with a new design strategy comprising efficient anoxic condition in the anodic chamber, adequate airflow to the cathode for enhancing oxygen reduction reactions, and a passive fuel pumping facility to the anode. A magnetic nanoparticle-based bio-nanocomposite matrix on the carbon-cloth electrode offered as a biocompatible enzyme immobilization matrix for harvesting electrons in the cell through the direct electron transfer mechanism as validated by cyclic voltammetry. Six units of the cells, when connected in a series, the device's potential increased to 4.3-fold (3.1 V) and rested at a stable state under a load with a half-life of ∼ 372 days and a coulombic efficiency of 60%. This high operational stability has been attributed to the efficient anoxic setup in the anodic chamber that supported the stability of alcohol oxidase, the activity of which was intact even after 49 days of the operation. This work also demonstrated that the prolonged interaction of molecular oxygen with the oxidase drastically inactivates it without affecting the structural integrity of the enzyme protein. This enzymatic fuel cell with improved design and functions is a step forward for achieving practical application as a standalone power supply to small-scale devices.

酶促生物燃料电池的操作稳定性、功率效率和技术简单性是这种绿色能源产生装置实际应用的研究重点。在这里，我们分别报告了使用乙醇氧化酶和胆红素氧化酶作为阳极和阴极催化剂制造的甲醇燃料纯生物燃料电池上关于这些问题的一些重要发现。该电池采用新的设计策略制造，包括阳极室中的高效缺氧条件、充足的气流到阴极以增强氧还原反应，以及到阳极的被动燃料泵送设施。碳布电极上的基于磁性纳米颗粒的生物纳米复合基质作为生物相容性酶固定基质，通过循环伏安法验证的直接电子转移机制在细胞中收集电子。六个单元的电池串联时，器件的电位增加到 4.3 倍 (3.1 V)，并在负载下处于稳定状态，半衰期约为 372 天，库仑效率为 60%。这种高运行稳定性归因于阳极室中有效的缺氧设置，支持酒精氧化酶的稳定性，即使在运行 49 天后，其活性仍完好无损。这项工作还表明，分子氧与氧化酶的长期相互作用会极大地使其失活，而不会影响酶蛋白的结构完整性。这种具有改进设计和功能的酶燃料电池是实现作为小型设备独立电源的实际应用的一步。