A Branched Rutile/Anatase Phase Structure Electrode with Enhanced Electron-Hole Separation for High-Performance Photoelectrochemical DNA Biosensor
Bingrong Wang,
Bingdong Yan,
Run Yuan,
Bin Qiao,
Guangyuan Zhao,
Jinchun Tu,
Xiaohong Wang,
Hua Pei,
Qiang Wu
Affiliations
Bingrong Wang
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
Bingdong Yan
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
Run Yuan
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
Bin Qiao
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
Guangyuan Zhao
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
Jinchun Tu
State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China
Xiaohong Wang
State Key Laboratory of Marine Resource Utilization in South China Sea, School 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
A photoelectrochemical (PEC) detection platform was built based on the branched rutile/anatase titanium dioxide (RA-TiO2) electrode. Theoretical calculations proved that the type-II band alignment of rutile and anatase could facilitate charge separation in the electrode. The self-generated electric field at the interface of two phases can enhance the electron transfer efficiency of the electrode. Carboxylated CdTe quantum dots (QDs) were applied as signal amplification factors. Without the target DNA presence, the CdTe QDs were riveted to the surface of the electrode by the hairpin probe DNA. The sensitization of CdTe QDs increased the photocurrent of the electrode significantly. When the target DNA was present, the structural changes of the hairpin probe DNA resulted in the failure of the sensitized structure. Benefiting from excellent electrode structure design and CdTe QDs sensitization strategy, the PEC assays could achieve highly sensitive and specific detection of target DNA in the range of 1 fM to 1 nM, with a detection limit of 0.23 fM. The electrode construction method proposed in this article can open a new avenue for the preparation of more efficient PEC sensing devices.
