亚稳相贵金属基催化选择性阳极及可植入紧凑式非酶生物燃料电池可行性的研究

With the development of medicine and engineering, implantable medical devices have been widely used in clinical, which can replace the function of the diseased organs or measure the physical and chemical parameters of the living body for the treatment of diseases. It’s a great boon for patients. At present, how to provide long-term and safe power for them is an important challenge, which becomes a key factor restricting the development. Abiotic biofuel cells have superior long-term stability and controlled safety, which are expected to meet the stringent power requirements of long-term medical implant devices. However, due to the lack of catalytic selectivity of the anode materials, the open circuit voltage of the abiotic biofuel cell with simple configuration is much lower than the theoretical value, and the output performance is unable to meet the needs of clinical practice. It has been reported that the catalytic properties of thermodynamic metastable phase precious metal-based materials strongly depend on the phase structure and have good controllability, which is expected to become a new strategy for anode materials of abiotic biofuel cells. In this study, new types of thermodynamic metastable phase precious metal-based nanomaterial are developed by regulating chemical composition, phase structure, size, microstructure, electronic structure. The mechanism of catalytic selectivity is studied in-depth in order to master the design rules of catalyst materials, relevant regulation methods and controllable preparation. Then, the compact abiotic biofuel cells are constructed, and the biosecurity and service performance in vivo are evaluated.

随着医学与工程学的融合，植入式医疗器件（心脏起搏器、电子耳蜗等）在临床中得到了广泛的应用，给患者带来巨大的福音，但面临着长期安全电能供应难题，成为制约发展的关键因素。非酶生物燃料电池具有优越的长期稳定性及安全性，有望满足植入式医疗器件的供电需求。然而，由于阳极材料的催化选择性不足使得简易构型的电池开路电压远低于理论值，输出性能难以满足临床应用。有研究报道热力学亚稳相贵金属基材料的催化性能强烈地依赖于相结构且具有很好的可调控性，有望成为非酶燃料电池阳极材料的新策略。因此，本研究拟制备亚稳相贵金属基纳米材料，并调控其组成、相结构、尺寸、微观形貌、电子结构等参数，考察阳极反应催化选择性的影响规律，实现新型高催化选择性阳极材料的可控制备。探索微-纳纤维结构膜电极的有效构建，组建面向植入式医疗器件供电的紧凑式非酶生物燃料电池，考察电池在体内的电能输出及抗衰减性能，并对其整体生物安全性能进行评估。

植入式医疗器件在临床上具有广泛的应用，给患者带来了巨大的福音。然而，如何实现长期安全稳定的电能供应仍是一个巨大的挑战，成为制约植入式医疗器件发展的关键因素。众多被研究的新的供电方式中，生物燃料电池由于能量转化效率高、操作条件温和、结构简单等优点被认为是极具应用前景的植入式医疗器件供电方式。传统的生物燃料电池是一种利用酶或微生物等催化剂将生物燃料中的化学能直接转化为电能的电化学装置。然而，酶和微生物的长期稳定性及安全隐患等问题使得酶生物燃料电池与微生物燃料电池作为长期植入式医疗器件电源方面的应用受到了很大的限制。非酶生物燃料电池多采用金属、合金及碳材料作为催化剂，具有优越的长期稳定性及可控的安全性，有望满足要求严格的长期植入式医疗器件的供电需求。然而，由于阳极材料的催化选择性不足使得简易构型的非酶生物燃料电池的开路电压远低于理论值，输出性能难以满足临床应用需求。本项目针对这一关键问题首先开展基于热力学亚稳相贵金属4H/fcc Au构筑新型纳米核壳结构材料的研究，通过电化学性能表征筛选了近十种相关材料，包括亚稳态Au纳米棒、Au纳米线、Au@Ag、Au@Ag@Pt、Au@Ag@Pd、Au@Zn、Au@Fe、Au@Pt、Au@石墨烯等，发现Au@Ag纳米材料对葡萄糖等含能物质具有一定的催化选择性。通过静电纺丝制备了导电基底负载的催化材料微纳纤维膜电极，组装制得新型紧凑式非酶生物燃料电池，开路电压达到了0.37 V，最大功率密度为8.3 μW cm-2，相比于相同工艺制得的酶基生物燃料电池（开路电压0.13 V，最大功率密度1.7μW cm-2）具有更优的性能。将制备的Au@Ag纳米材料与细胞共培养，细胞呈现明显的活性增殖，表明Au@Ag纳米材料具有很好的生物相容性。将非酶生物燃料电池植入大兔体内50 h后，性能仅衰减2.5%，说明所构建的非酶生物燃料电池具有很好的长期稳定性。综上所述，基于热力学亚稳相贵金属纳米催化材料的研究有望构建高性能非酶生物燃料电池，为满足临床实践中植入式医疗器件的供电需求打下坚实的基础。