Fabrication, properties, and sensing applications of TiO2 nanotubes have been reviewed, and the highly ordered TiO2 nanotube arrays made by anodic oxidation in fluoride-contained electrolytes highlighted. The effect o...Fabrication, properties, and sensing applications of TiO2 nanotubes have been reviewed, and the highly ordered TiO2 nanotube arrays made by anodic oxidation in fluoride-contained electrolytes highlighted. The effect of anodization parameters (electrolyte, pH, and voltage) on the titania nanotube size and shape were discussed. The excellent biocompatibility of TiO2, the high orienta- tion, the large surface area with tunable pore sizes, as well as the high electron transfer rate along with the nanotubes make TiO2 nanotube array an ideal substrate for the sensor's fabrication and application. The sensors based on the TiO2 nanotube arrays for sensing hydrogen, oxygen, humidity, glucose and hydrogen peroxide all exhibited low detection limit, high stability, very good reproducibility and high sensitivity.展开更多
TiO2 nanotube (NT) arrays have been prepared by anodic oxidation of a Ti sheet,and carbon-deposited TiO2 NT arrays have been prepared by annealing TiO2 NT arrays in carbon atmosphere. The biocompatibility of the as-pr...TiO2 nanotube (NT) arrays have been prepared by anodic oxidation of a Ti sheet,and carbon-deposited TiO2 NT arrays have been prepared by annealing TiO2 NT arrays in carbon atmosphere. The biocompatibility of the as-prepared NT arrays was investigated by observing the growth of osteosarcoma (MG-63) cells on the NT arrays. The application of the TiO2 NT arrays as a drug delivery vehicle was investigated. Both the TiO2 NTs and the carbon-modified TiO2 NTs have good biocompatibility supporting the normal growth and adhesion of MG-63 cells with no need of extracellular matrix protein coating. The one end-opened TiO2 NTs can be easily filled with drugs,working as an efficient drug delivery vehicle.展开更多
Detection of miRNAs presents a particular challenge because of their limited size, high sequence homo- logy and greatly various expression level. In this work, an ultrasensitive, label-free and isothermal miRNA detect...Detection of miRNAs presents a particular challenge because of their limited size, high sequence homo- logy and greatly various expression level. In this work, an ultrasensitive, label-free and isothermal miRNA detection was developed based on asymmertric hairpin probe, exonuclease I（Exo I） and SYBR Green I. The method employed asymmetric hairpin probe to perform cycled polymerization and Exo I to reduce background signal. In the presence of the target miRNA, the target triggers probe-mediated cycled polymerization reactions to generate lots of dsDNA products. The dsDNA product effectively prevents itself from being degraded by Exo I and permitted the insertion of more fluorescence dye into it to enlarge the fluorescence signal. In the absence of the target miRNA, there was no probe-mediated polymerization reaction, and the probe was digested by Exo I added, which minimized the intercala- tion of fluorescence dye to reduce the background signal. The combination of the probe-mediated cycled polymeriza- tion with the Exo 1-assisted background reduction allows us to achieve a detection limit of 5× 10^-18 mol/L. Owing to its ultrasensitivity, excellent specificity, convenience and low-cost, this method might hold out great promise in miRNA detection.展开更多
基金supported by the Major State Basic Research Development Program of China (Grant No. 2009CB421601)Natural Science Foundation of Hunan Province, China (Grant No. 08JJ3113)Innovation Project in Postgraduate Education for Excellent Doctors (Grant No. 521218019)
文摘Fabrication, properties, and sensing applications of TiO2 nanotubes have been reviewed, and the highly ordered TiO2 nanotube arrays made by anodic oxidation in fluoride-contained electrolytes highlighted. The effect of anodization parameters (electrolyte, pH, and voltage) on the titania nanotube size and shape were discussed. The excellent biocompatibility of TiO2, the high orienta- tion, the large surface area with tunable pore sizes, as well as the high electron transfer rate along with the nanotubes make TiO2 nanotube array an ideal substrate for the sensor's fabrication and application. The sensors based on the TiO2 nanotube arrays for sensing hydrogen, oxygen, humidity, glucose and hydrogen peroxide all exhibited low detection limit, high stability, very good reproducibility and high sensitivity.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20775024 & 20827006)the Natural Science Foundation of Hunan Province (Grant No. 09JJ4007)
文摘TiO2 nanotube (NT) arrays have been prepared by anodic oxidation of a Ti sheet,and carbon-deposited TiO2 NT arrays have been prepared by annealing TiO2 NT arrays in carbon atmosphere. The biocompatibility of the as-prepared NT arrays was investigated by observing the growth of osteosarcoma (MG-63) cells on the NT arrays. The application of the TiO2 NT arrays as a drug delivery vehicle was investigated. Both the TiO2 NTs and the carbon-modified TiO2 NTs have good biocompatibility supporting the normal growth and adhesion of MG-63 cells with no need of extracellular matrix protein coating. The one end-opened TiO2 NTs can be easily filled with drugs,working as an efficient drug delivery vehicle.
基金Supported by the National Natural Science Foundation of China（No.21275043） and the National Basic Research Program of China（No .2009CB421601）.
文摘Detection of miRNAs presents a particular challenge because of their limited size, high sequence homo- logy and greatly various expression level. In this work, an ultrasensitive, label-free and isothermal miRNA detection was developed based on asymmertric hairpin probe, exonuclease I（Exo I） and SYBR Green I. The method employed asymmetric hairpin probe to perform cycled polymerization and Exo I to reduce background signal. In the presence of the target miRNA, the target triggers probe-mediated cycled polymerization reactions to generate lots of dsDNA products. The dsDNA product effectively prevents itself from being degraded by Exo I and permitted the insertion of more fluorescence dye into it to enlarge the fluorescence signal. In the absence of the target miRNA, there was no probe-mediated polymerization reaction, and the probe was digested by Exo I added, which minimized the intercala- tion of fluorescence dye to reduce the background signal. The combination of the probe-mediated cycled polymeriza- tion with the Exo 1-assisted background reduction allows us to achieve a detection limit of 5× 10^-18 mol/L. Owing to its ultrasensitivity, excellent specificity, convenience and low-cost, this method might hold out great promise in miRNA detection.
