A non-labeled DNA biosensor based on light addressable potentiometric sensor modified with TiO_2 thin film  

作　　者：Xiao-lin ZONG Chun-sheng WU Xiao-ling WU Yun-feng LU Ping WANG 

机构地区：[1]Biosensor National Special Laboratory, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China

出　　处：《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》2009年第11期860-866,共7页浙江大学学报（英文版）B辑（生物医学与生物技术）

基　　金：Project supported by the National Natural Science Foundation of China (Nos. 30627002 and 60725102);the Interdisciplinary Research Foundation of Zhejiang University (No. 2009-15), China

摘　　要：Titanium dioxide (TiO2) thin film was deposited on the surface of the light addressable potentiometric sensor (LAPS) to modify the sensor surface for the non-labeled detection of DNA molecules. To evaluate the effect of ultraviolet (UV) treatment on the silanization level of TiO2 thin film by 3-aminopropyltriethoxysilane (APTS),fluorescein isothiocyanate (FITC) was used to label the amine group on the end of APTS immobilized onto the TiO2 thin film. We found that,with UV irradiation,the silanization level of the irradiated area of the TiO2 film was improved compared with the non-irradiated area under well-controlled conditions. This result indicates that TiO2 can act as a coating material on the biosensor surface to improve the effect and efficiency of the covalent immobilization of biomolecules on the sensor surface. The artificially synthesized probe DNA molecules were covalently linked onto the surface of TiO2 film. The hybridization of probe DNA and target DNA was monitored by the recording of I-V curves that shift along the voltage axis during the process of reaction. A significant LAPS signal can be detected at 10 μmol/L of target DNA sample.Titanium dioxide （TiO2） thin film was deposited on the surface of the light addressable potentiometric sensor （LAPS） to modify the sensor surface for the non-labeled detection of DNA molecules. To evaluate the effect of ultraviolet （UV） treatment on the silanization level of TiO2 thin film by 3-aminopropyltriethoxysilane （APTS）, fluorescein isothiocyanate （FITC） was used to label the amine group on the end of APTS immobilized onto the TiO2 thin film. We found that, with UV irradiation, the silani- zation level of the irradiated area of the TiO2 film was improved compared with the non-irradiated area under well-controlled conditions. This result indicates that TiO2 can act as a coating material on the biosensor surface to improve the effect and effi- ciency of the covalent immobilization of biomolecules on the sensor surface. The artificially synthesized probe DNA molecules were covalently linked onto the surface of TiO2 film. The hybridization of probe DNA and target DNA was monitored by the recording of I-V curves that shift along the voltage axis during the process of reaction. A significant LAPS signal can be detected at 10 μmol/L of target DNA sample.

关 键 词：DNA biosensor Titanium dioxide （Ti02） thin film Light addressable potentiometric sensor （LAPS） SILANIZATION Fluorescein label Gene chip 

分 类 号：Q503[生物学—生物化学]