Abstract：
Aerogels derived from the colloidal nanoparticles featured with hierarchical interconnected pore-rich networks guarantee their great potentials in various applications. Herein, the controllable assembly of three-dimensional aerogels based on Au nanoparticles (Au NPs) and reduced graphene oxide (rGO) nanosheets as building blocks via a bottom-up approach have been systematically clarified. The difference of building blocks and their assembly sequence were crucially to the final aerogel morphologies and electrochemical properties. Specifically, the highly porous graphene-gold dual aerogels (rGO-Au DAGs) with interconnected rGO nanosheets and Au nanowires showed high conductivity, large surface area and good biocompatibility. Thus, it was employed as an excellent matrix to immobilize enzyme for high-efficient bioelectrocatalysis. Taking bilirubin oxidase as an example, a more positive on-set potential (0.60 V) and a larger catalytic current density (0.77 mA cm-2@0.40 V) than those of other rGO-Au assemblies were achieved for direct bioelectrocatalytic O2 reduction. This study will provide an efficient strategy for unique dual-structural aerogels design and shed light to develop new functional materials for bioelectrocatalytic applications such as biosensors and biofuel cells.
摘要：
由具有分层互连的富孔网络的胶体纳米颗粒衍生的气凝胶保证了它们在各种应用中的巨大潜力。在这里，通过自下而上的方法，基于Au纳米颗粒（AuNP）和还原氧化石墨烯（rGO）纳米片作为构建块的三维气凝胶的可控组装已经得到了系统的阐明。结构单元及其组装顺序的差异对最终的气凝胶形态和电化学性能至关重要。具体来说,具有互连的rGO纳米片和Au纳米线的高度多孔石墨烯-金双气凝胶（rGO-AuDAG）显示出高导电性，表面积大，生物相容性好。因此，它被用作高效生物电催化固定化酶的优良基质。以胆红素氧化酶为例,对于直接的生物电催化O2还原，与其他rGO-Au组件相比，获得了更大的正导通电位（0.60V）和更大的催化电流密度（0.77mAcm-2@0.40V）。这项研究将为独特的双结构气凝胶设计提供有效的策略，并为开发用于生物传感器和生物燃料电池等生物电催化应用的新型功能材料提供启示。
