Graphene-assisted titanium dioxide Z-mechanism photoelectrode as enzymatic glucose biosensor
Fei Li,
Bin Zhang,
Bingdong Yan,
Qian Chen,
Xiaohong Wang,
Kexi Zhang,
Hua Pei,
Qiang Wu,
Delun Chen,
Jinchun Tu
Affiliations
Fei Li
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Bin Zhang
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Bingdong Yan
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Qian Chen
Department of Clinical Laboratory, The First Affiliated Hospital of Hainan Medical University, Haikou 570102, China
Xiaohong Wang
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Kexi Zhang
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Hua Pei
Department of Clinical Laboratory of the Second Affiliated Hospital, School of Tropical Medicine, Key Laboratory of Emergency and Trauma of Ministry of Education, Research Unit of Island Emergency Medicine, Chinese Academy of Medical Sciences (No. 2019RU013), Hainan Medical University, Haikou 571199, China
Qiang Wu
Department of Clinical Laboratory of the Second Affiliated Hospital, School of Tropical Medicine, Key Laboratory of Emergency and Trauma of Ministry of Education, Research Unit of Island Emergency Medicine, Chinese Academy of Medical Sciences (No. 2019RU013), Hainan Medical University, Haikou 571199, China
Delun Chen
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Jinchun Tu
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials Science and Engineering, Hainan University, Haikou 570228, China
Highly exposed surfaces of anatase TiO2 crystals are of interest due to their excellent photogenerated electron–hole pair separation effect and high photocatalytic activity. In this work, a Z-mechanism biosensor with reduced graphene oxide (rGO) and anatase TiO2 nanocrystals combined with PDA (TiO2/rGO/PDA) was successfully synthesized. rGO was combined with the co-exposed (001) and (101) facets of TiO2 nanocrystals to construct a Z-mechanism in which rGO acts as an electron transport medium and provides a channel for the transfer of electrons, resulting in TiO2 nanocrystals with high photoelectron–hole pair separation efficiency and strong redox ability. The coated PDA polymer not only could absorb visible light but also has good stability and biocompatibility, which helps to increase the adsorption of target enzyme molecules. The TiO2/rGO/PDA/GOx biosensor with the Z-mechanism displays the sensitivity of 13.82 μA mM−1 cm−2 in 0.1M PBS solution (pH = 7.4) with a linear range of 0–3 mM and the LOD of 0.034 µM. In general, the application of the Z-mechanism in biosensors would provide a new orientation for the design of biosensors.
