可调控双重响应立体金杂化碳基酶电极及其可“开/关”燃料电池的性能

Enzymatic biofuel cells (EBFC) with multi-responsive and switchable features are promising bio-powers for their potential application in implantable smart medical devices, which have attracted increasing attention due to its mild working conditions, high biocompatibility and high availability of stimuli in physiological environment. However, challenges still exist on the way to the commercialization of stimuli-responsive EBFC. For instance, introducing insulated stimuli-responsive polymers by drop casting or traditional radical polymerization on the surface of electrodes may significantly reduce the electrochemical performances of electrodes and the related EBFC. Another drawback of current stimuli-responsive electrodes is the insufficient stability and sensitivity for long-term running of the resulted EBFC. ..In this project, novel type of three-dimensional porous gold/carbon based dual-responsive enzymatic electrodes for “on-off” switchable biofuel cells are proposed. Firstly, porous gold hybrid three-dimensional macroporous foam graphene electrode (Au-MFG) is prepared by repeatedly co-electrodepositing gold/stannum and corroding stannum. The obtained Au-MFG is then surface modified to introduce an initiator for surface-initiated atom transfer radical copolymerization (ATRP) of temperature- and pH-responsive monomers to form dual-responsive copolymer-functionalized Au-MFG (SRCP-Au-MFG). The proposed ATRP process allow well-adjusting distribution and structure of responsive copolymer brushes, which is the key to combine precise control of on-demand stimuli-responses with high electric performance of the electrode. The complex of enzymes and multi-walled carbon nanotubes (En@MWNTs) is prepared through oriented immobilization of biotin-enzyme on streptavidin-modified functional carbon nanotube. The large-amount immobilization of En@MWNTs at the SRCP-Au-MFG electrode is performed by “static equilibrium-vacuum filtration-static equilibrium” interfacial assembly, which is expected to achieve higher enzymatic activity than that by traditional chemical immobilization and higher stability than that by physical immobilization. The relationship between the electrode with different hierarchical architectures and the electro-catalysis performances, stimuli-responsive property as well as the stability are then explored to optimize the resulted dual-responsive enzymatic electrodes and EBFC...The strategy in this project on precise regulation and control of the structure of switchable enzymatic electrodes and optimization of their electric and stimuli-responsive performances will prompt the further development of switch-on-demand biofuel cells and biocomputing responding to complex external signals.

可“开/关”型酶生物燃料电池（EBFC）是植入式医疗器械动力的首选。但EBFC存在功率密度低、稳定性差等问题；可“开/关”EBFC因电极表面存在响应性聚合物而使其电性能更差，“开/关”可控性有待提高。本项目利用分步循环共沉积、刻蚀法在泡沫石墨烯表面沉积立体网孔金，获得结构可控的金网孔碳杂化电极（Au-MFG）；在该电极表面通过可控共聚（ATRP）温度与pH值刺激响应性单体，获得双重刺激响应共聚物刷电极（SRCP-Au-MFG）；调控电极表面引发剂的分布、ATRP工艺、共聚物刷多级结构与形貌，调控电极电性能与双重刺激之响应行为；利用亲和素-生物素相互作用调制碳纳米管与酶的复合体（En@MWNTs）结构，调控En@MWNTs与SRCP-Au-MFG界面特殊组装方法，构筑载酶量高、刺激响应行为可调控的酶生物电极，探索电极物理、化学多层次结构与其各性能之关系，为可“开/关”BEFC的应用奠定基础。

可“开/关”型酶生物燃料电池（EBFC）是植入式医疗器械动力的首选，但其功率密度低、稳定性差，可“开/关”EBFC因电极表面存在响应性聚合物使其电性能更差、“开/关”可控性低等问题。..建立了动态模板循环电还原等策略构建珊瑚状立体网孔金杂化电极新方法，提高电极载酶量，改善其电子传导性；利用共价键合方法实现了酶交联聚集体在其上的定向固定，构筑了高效稳定酶电极。..建立了电极表面自由基聚合、表面活性原子转移自由基聚合、酶促自由基聚合制备聚合制备刺激响应酶电极方法，发现了铜促自由基聚合反应规律，实现了聚物刷在电极表面的分布、聚集状态及表面形貌的精确调控。..在柔性导电基底上构建了立体网孔导电电极基底，共价固定方法分别固定葡萄糖氧化酶及漆酶，组建了全酶燃料电池，其开路电压为0.58 V，最大输出功率为2.32 mW cm-2，经过1000次弯折后最大输出功率下降小于1 %。..本项目的研究为可“开/关”型酶生物燃料电池及可“开/关”型传感器的应用奠定了基础；项目设计的多重刺激响应性酶电极的构筑方法、电极表面功能化的方法等对相关领域的研究与应用也具有一定的借鉴价值。..发表学术论文14篇，SCI收录13篇；申请发明专利4件，获得授权1件。