Surface- and interface-regulated graphdiyne-based composites and their applications in the detection of small biological signaling molecules

Abstract

<p indent="0mm">Graphdiyne (GDY) is a novel diacetylene carbon allotrope with a two-dimensional (2D) planar network structure consisting of sp² and sp carbon atoms. Since its successful fabrication on the surface of a copper foil during experimentation, GDY has been gaining increasing attention owing to its high π-conjunction, wide interplanar spacing, tunable electronic properties, interesting structure, and excellent physicochemical stability. To date, extensive research efforts have been channeled toward theoretical prediction and synthesis methods and the applications of GDY and its derivatives in the fields of batteries, catalysts, biosensing, and biomedicine. Specifically, the unique properties of GDY, including a large hydrophobic planar network, specific surface area, and binding energies, render it an excellent compound for other functional materials or molecules to achieve high catalytic performance in the fields of biosensing and bioelectric chemistry. However, despite the great advances in GDY, reviews on the achievements are limited. The current review summarizes the recent advances of GDY and its derivatives in the sensing of small biological signaling molecules, focusing on the strategies for tailoring the surface and interface of the materials. The review also explores the relationship between the physicochemical properties of the materials and their sensing performance. The main contents of this review are as follows: First, we explain the structure and optical and electrical properties of GDY materials and describe the theoretical and experimental investigations on the basic properties of GDY. Owing to the unique structures of GDY, including its three-dimensional network pores and high π-conjunction, GDY can be facilely combined with other functional materials to improve catalytic ability, which is beneficial for achieving high sensitivity for sensing small molecules. Next, we discuss the functionalization strategies of GDY. The presence of carbon–carbon triple bonds in GDY allows it to be doped with metallic and nonmetallic species, including nitrogen, boron, phosphorus, copper, and palladium. Heteroatom doping can efficiently tune the electronic structures of GDY, which can enhance the sensing performance of GDY and its derivatives toward small biological signaling molecules. Moreover, the applications of GDY and its derivatives in sensing small biological signaling molecules are discussed and analyzed. We focus on the sensing mechanism and performance enhancement of GDY and its derivatives toward glucose, dopamine, ascorbic acid, uric acid, hydrogen peroxide, and nitric oxide. Moreover, we raise the key issues that need to be addressed in the future. Great research progress has been made on the synthesis of GDY-based materials and their applications. However, GDY-based materials and their sensing applications are still not well understood. For instance, to date, only GDY has been successfully synthesized. Other structures of graphynes have only been predicted through theoretical studies. Establishing other structures of graphynes in a controllable and scalable manner is highly difficult, but such techniques can produce structures with rich active sites and enhanced catalytic ability. Moreover, heteroatom doping can modify the physicochemical, electrical, and structural properties of GDY-based materials. Nevertheless, precisely doping heteroatoms on the GDY surface in a controllable manner remains a great challenge. With the remarkable advances in the exploration of new and practical synthesis methods, the interfacial reaction processes and the effects of the structure-activity relationship on the sensing performance of GDY-based materials can be elucidated. This can help expand the knowledge of biochemical and bioelectric applications related to GDY and its derivatives.