A non-labeled DNA biosensor based on light addressable potentiometric sensor modified with TiO2 thin film

• Published in: Journal of Zhejiang University. B. Science Vol. 10; no. 11; pp. 860 - 866
• Main Authors: Zong, Xiao-lin, Wu, Chun-sheng, Wu, Xiao-ling, Lu, Yun-feng, Wang, Ping
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Zhejiang University Press 01-11-2009; Springer Nature B.V; Zhejiang University Press
• Subjects: Biomedical and Life Sciences; Biomedicine; Biosensing Techniques; Biotechnology; Deoxyribonucleic acid; DNA; DNA生物传感器; Equipment Design; Fluorescein - chemistry; Fluorescein-5-isothiocyanate - chemistry; Genetic testing; Hydrolysis; Light; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis - instrumentation; Oxygen - chemistry; Potentiometry - instrumentation; Potentiometry - methods; Propylamines; Silanes - chemistry; Thin films; Titanium - chemistry; Ultraviolet Rays; 二氧化钛薄膜; 光寻址电位传感器; 异硫氰酸荧光素; 紫外线照射; 薄膜传感器; 表面涂层材料; DNA biosensor; Light addressable potentiometric sensor (LAPS); Fluorescein label; thin film; Silanization; Q81; Titanium dioxide (TiO; Gene chip
• ISSN: 1673-1581; 1862-1783
• DOI: 10.1631/jzus.B0920090

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.