Amino-propyltriethoxysilane Modified Heavy Metal Sensor Based on Silicon Nanowire Arrays (original) (raw)
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IOP Conference Series: Materials Science and Engineering
Silicon (Si) nanostructure was prepared using a cheap and in-house technique. The device was fabricated via dry oxide etching approach with a controlled oxygen flow rate in an oxidation furnace, a network of uniform Si nanowires were successfully fabricated. The device was functionalized by (3-aminopropyl) triethoxysilane (APTES) to serve as a sensor for heavy metal detection. The amino-functionalized Si nanowires were characterized based on variation SPX spectra of four different element that, O, OH, NH 2 and Si-O-NH 2. Three major peaks in the C 1s region one at 289 eV is were detected indicating for the Si-O attaching, values of 287eV 30 for Si-OH, 285eV for NH 2 and 83eV for Si-O-NH 2 representing hydroxide, amine and modified silicon surface that that established nitrogen atoms (-NH2,-NH-). Thus, the study identifies different chemical environments to identify heavy metals in water.
The study proposed characterization and optimization of silicon nanosensor for specific detection of heavy metal. The sensor was fabricated in-house and conventional photolithography coupled with size reduction via dry etching process in an oxidation furnace. Prior to heavy metal heavy metal detection, the capability to aqueous sample was determined utilizing serial DI water at various. The sensor surface was surface modified with Organofunctional alkoxysilanes (3-aminopropyl) triethoxysilane (APTES) to create molecular binding chemistry. This has allowed interaction between heavy metals being measured and the sensor component resulting in increasing the current being measured. Due to its, excellent detection capabilities, this sensor was able to identify different group heavy metal species. The device was further integrated with sub-50µm for chemical delivery.
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Development of a design and technology of sensors for analysis of a small volume of aqueous solutions is presented in the work. A nanowire junctionless n-type FET has been manufactured for this purpose. The fabrication process and SEM examination have been described. Electrical characteristics of the multiwire FETs have been measured in KCl solutions and in pH buffer solutions. Results of APTES functionalization have been also presented.
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International Journal of Environmental Analytical Chemistry, 2005
⎯Electrochemical methods for heavy metals detection have attracted considerable attention due to their simplicity, rapidity and high sensitivity. Voltammetric methods are a valid and very effective alternative for the simultaneous determination of heavy metals. An independent atomic absorption spectroscopic analysis of the seaweed sample was carried out and the results were compared with the World Health Organization permissible limits. The sample was clearly observed in the atomic force microscopic images, characterized by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The electrochemical behavior of heavy metals on a bare glassy carbon electrode and a multiwalled carbon nanotubes modified glassy carbon electrode was studied by cyclic voltammetry, linear sweep anodic voltammetry, square wave anodic voltammetry and differential pulse anodic voltammetry. Very good responses were observed for all the metals when the modified electrode was employed.
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Detection and quantification of very small amounts of biological species become necessary to allow an early detection of malignant disease and the development of personalized medicine. Currently, fluorescence detection or colorimetry are the most frequently used techniques. Although very sensitive, the necessary labelling step of the biotargets can alter their recognition properties and these methods have a low potential for
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Applied Physics A, 2012
We report a simple and effective method to develop long-term stable, top-down fabricated silicon nanowire (SiNW) pH sensors along with systematic studies on the performance of the sensors. In this work, we fabricated the SiNW pH sensors based on top-down fabrication processes. In order to improve the stability of the sensor performance, the sensors were coated with a passivation layer (PECVD-based silicon nitride) for effective electrical insulation and ion-blocking. The stability, pH sensitivity, and repeatability of the sensor response are critically analyzed with regard to the physics of sensing interface between sample liquid and the sensor surface. Also, trade-off between the stability and pH sensitivity of the sensor response is discussed.
Journal of Physics: Conference Series, 2013
Due to its potential risk to human health and ecology, the presence of heavy metals in water demands of techniques to determine them in a simple and economical way. Currently, new developments of light emitters and detectors open a window of opportunities to use optical properties to analyze contaminated water. In this paper, a silicon sensor developed to extend its sensitivity up to the UV range is used to determine heavy metals in water. Cadmium, Zinc, Lead, Copper and Manganese mixed in pure water at different concentrations were used as test samples. The photocurrent obtained by the light that passes through the samples was used to determine the optical transmittance of pure and contaminated water. Preliminary results show a good separability between samples, which can be used for qualitative and quantitative detection of such heavy metals in water.