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1.
Optical Sol-Gel-Based Dissolved Oxygen Sensor: Progress Towards a Commercial Instrument 总被引:1,自引:0,他引:1
Mcdonagh C.M. Shields A.M. Mcevoy A.K. Maccraith B.D. Gouin J.F. 《Journal of Sol-Gel Science and Technology》1998,13(1-3):207-211
A dissolved oxygen sensor based on fluorescence quenching of the oxygen-sensitive ruthenium complex, [Ru(II)-tris(4,7-diphenyl-1,10-phenanthroline]2+, which has been immobilized in a porous silica sol-gel-derived film, is reported. Ormosil sensing films were fabricated using modified silica precursors such as methyltriethoxysilane (MTEOS) and ethyltriethoxysilane (ETEOS) and were dip-coated onto planar glass substrates. Tailoring of the films for dissolved oxygen (DO) sensing is described whereby sensor response is optimized by maximizing film hydrophobicity by the use of the modified precursors. Sensor performance parameters such as limit of detection and sensor resolution are reported. Issues such as dye leaching and photobleaching are discussed. Progress towards a commercial instrument is reported. 相似文献
2.
Luminescence Quenching Behavior of Oxygen Sensing ORMOSIL Films Based on Ruthenium Complex 总被引:1,自引:0,他引:1
An organically modified silicate(ORMOSIL) based optical sensor response to gaseous O2 or O2 dissolved in water is presented. The oxygen sensing film mechanism is based on the principle of fluorescence quenching of tris(4,7-diphenyl-l , 10-phenanthroline) ruthenium ( ) ([Ru(dpp)3]2+), which has been entrapped in a porous ORMOSIL film. In order to establish optimum film-processing parameters, comprehensive investigations, including the effects of the polarity and the hydrophobicity of the sensing film on oxygen quenching response and response time, were carried out. The film hydrophobicity increased as a function of dimethyl-dimethoxysilane (DiMe-DMOS) content, which is correlated with enhanced oxygen sensor performance. The sensor developed in the present work exhibits the advantages of fast response time and good reversibility. The detection limits are 0. 5 % and 0. 3 g/mL for O2 in the gaseous and the aqueous phases, respectively. 相似文献
3.
The development of a simple, efficient and sensitive sensor for dissolved oxygen is proposed using a novel type of porous carbon composite membrane/glassy carbon electrode based on the low-cost common filter paper by a simple method. The resulting device exhibited excellent electrocatalytic activities toward the oxygen reduction reaction. Scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements demonstrated that the porous morphology and uniformly dispersed Fe3C nanoparticles of the PCCM play an important role in the oxygen reduction reaction. A linear response range from 2μmol/L up to 110 μmol/L and a detection limit of 1.4 μmol/L was obtained with this sensor. The repeatability of the proposed sensor, evaluated in terms of relative standard deviation, was 3.0%. The successful fabrication of PCCM/GC electrode may promote the development of new porous carbon oxygen reduction reaction material for the oxygen reduction sensor. 相似文献
4.
Oxygen concentration is an important parameter in environmental, chemical and other fields. Oxygen sensor based on luminescence quenching by oxygen have been developed and wide applied. The oxygen quenching process is described by the Stern-Volmer equation. Ruthenium complex are chosen as fluorescence indicator because they are particularly attractive for oxygen sensing, exhibit high luminescent quantum yield, long excited-state lifetime, large Stokes shift, and strong absorption in the blue-green spectral region[1]. The sensor involves immobilizing the ruthenium complex within a porous sol-gel-processed film. Sol-gel process has many advantages as a method of immobilization. At ambient temperature, it allows the fabrication of a tough, inert, porous glass material with a high surface area. Sol-gel-derived silica film has a low optical absorption in the visible and UV region of the spectrum and is relatively inexpensive to produce[2]. 相似文献
5.
A Water-Soluble Luminescence Oxygen Sensor 总被引:1,自引:0,他引:1
We developed a water-soluble luminescent probe for dissolved oxygen. This probe is based on (Ru[dpp(SO3 Na)2 ]3 ) Cl2 , which is a sulfonated analogue of the well-known oxygen probe (Ru[dpp]3 )Cl2 . The compound dpp is 4,7-diphenyl-1,10-phenanthroline and dpp(SO3 Na)2 is a disulfonated derivative of the same ligand. In aqueous solution in the absence of oxygen (Ru[dpp(SO3 Na)2 ]3 )Cl2 displays a lifetime of 3.7 μs that decreases to 930 ns on equilibrium with air and 227 ns on equilibrium with 100% oxygen. The Stern–Vohner quenching constant is 11330 M−1 . This high oxygen-quenching constant means that the photoluminescence of Ru(dpp[SO3 Na]2 )3 Cl2 is 10% quenched at an oxygen concentration of 8.8 x 10−6 M , or equilibration with 5.4 torr of oxygen. The oxygen probe dissolved in water displays minimal interactions with lipid vesicles composed of dipalmityl-L-α-phosphatidyl glycerol but does appear to interact with human serum albumin. The absorption maximum near 480 nm, long lifetime and large Stokes'shift allow this probe to be used with simple instrumentation based on a light-emitting diode light source, allowing low-cost oxygen sensing in aqueous solutions. To the best of our knowledge this is the first practical water-soluble oxygen sensor. 相似文献
6.
P. Lavin C.M. McDonagh B.D. MacCraith 《Journal of Sol-Gel Science and Technology》1998,13(1-3):641-645
Recent work has indicated that Ormosil films, fabricated from organically modified precursors, produce better sensor performance for some specific applications, compared to films fabricated from conventional sol-gel precursors such as TEOS or TMOS. This paper aims to compare film properties and sensor behavior for films fabricated from tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS) silica precursors and both methyltrimethoxysilane (MTMS) and methyltriethoxysilane (MTES) organically modified precursors. Microstructural differences, for example, porosity changes due to the different precursor backbone structures, are interrogated by monitoring oxygen gas and aqueous-phase sensor response. Oxygen sensing using these films is enabled by incorporating in the films an oxygen-sensitive ruthenium dye whose fluorescence is quenched in the presence of oxygen. Film properties such as thickness, thickness stabilization time, as well as sensor response, are discussed in terms of relative hydrolysis and condensation behavior for the different precursors. Film hydrophobicity, an issue which has been identified as being of crucial importance for optimum dissolved oxygen sensor response, is discussed and contact angle measurements are used to investigate the degree of hydrophobicity for different film types. The main motivation for this work is film optimization for optical gas-phase and dissolved oxygen sensors. 相似文献
7.
An amperometric sensor system, based on a repetitive double step potential method at a glassy carbon electrode, has been developed for the simultaneous measurement of hydrogen peroxide and oxygen concentrations. The current measured at a potential of –1 V (vs. Ag/AgCl/saturated Cl–) corresponds to the sum of the reduction currents of hydrogen peroxide and dissolved oxygen. The current measured at –0.55 V (vs. Ag/AgCl/saturated Cl–) is due to the reduction of dissolved oxygen to hydrogen peroxide. Alternatively, the concentration of dissolved oxygen can also be determined using a Clark electrode. The concentration of hydrogen peroxide and dissolved oxygen during enzymatic conversion of glucose can be followed on line and be used to control the process. 相似文献
8.
Dorota Wencel John P. Moore Niall Stevenson Colette McDonagh 《Analytical and bioanalytical chemistry》2010,398(5):1899-1907
The focus of this work is on the development and characterisation of a fluorescence-based ratiometric sol–gel-derived dissolved
carbon dioxide (dCO2) sensor for use in environmental monitoring applications. Fluorescence-based dCO2 sensors are attractive as they facilitate the development of portable and low-cost systems that can be easily deployed outside
the laboratory environment. The sensor developed for this work exploits a pH fluorescent dye 1-hydroxypyrene-3,6,8-trisulfonic
acid, ion-paired with cetyltrimethylammonium bromide (HPTS-IP), which has been entrapped in a hybrid sol–gel-based matrix
derived from n-propyltriethoxysilane along with the liphophilic organic base. The sensor spot deposited on a cover slip has been interrogated
with a robust, ratiometric optical probe that combines effective fluorescence excitation and detection and thus facilitates
the production of a highly sensitive sensor system using low-cost optoelectronic components. The probe design involves the
use of dual-LED excitation in order to facilitate ratiometric operation and uses a silicon PIN photodiode. HPTS-IP exhibits
two pH-dependent changes in excitation bands, which allows for dual excitation ratiometric detection as an indirect measure
of the dCO2. Such measurements are insensitive to changes in dye concentration, leaching and photobleaching of the fluorophore and instrument
fluctuations unlike unreferenced fluorescence intensity measurements. The performance of the sensor system is characterised
by a high degree of repeatability, reversibility and stability. Calculated limit of detection for the sensor was 35 ppb. The
sensor probe was used to monitor dCO2 levels in a laboratory-based aquatic habitat, and the expected diurnal pattern was clearly visible. The influence of temperature,
biofouling and photobleaching on sensor performance has been also investigated. 相似文献
9.
10.
A biosensor for the specific determination of hydrogen peroxide was developed using catalase (EC 1.11.1.6) in combination with a dissolved oxygen probe. Catalase was immobilized with gelatin by means of glutaraldehyde and fixed on a pretreated teflon membrane served as enzyme electrode. The electrode response was maximum when 50 mM phosphate buffer was used at pH 7.0 and at 35 degrees C. The biosensor response depends linearly on hydrogen peroxide concentration between 1.0x10(-5) and 3.0x10(-3) M with a response time of 30 s. The sensor is stable for >3 months so in this period >400 assays can be performed. 相似文献
11.
Yan Xiong Jing Xu Dao-qian Zhu Chun-feng Duan Ya-feng Guan 《Journal of Sol-Gel Science and Technology》2010,53(2):441-447
A fiber-optic sensor based on fluorescence quenching was designed for dissolved oxygen (DO) detection. The fluorinated xerogel-based
sensing film of the present sensor was prepared from 3, 3, 3-trifluoropropyltrimethoxysilane (TFP–TriMOS). Oxygen-sensitive
fluorophores of tris (2, 2′- bipyridine) ruthenium (II) (Ru(bpy)32+) were immobilized in the sensing film and the emission fluorescence was quenched by dissolved oxygen. In the sensor fabrication,
a two-fiber probe was employed to obtain the best fluorescence collection efficiency and the sensing film was attached to
the probe end. Scanning electron microscope (SEM), UV–Vis absorption spectroscopy (UV–Vis) and fourier transform infrared
spectroscopy (FTIR) measurements have been used to characterize the sensing film. The sensor sensitivity is quantified by
I
deoxy/I
oxy, where I
deoxy and I
oxy represented the detected fluorescence intensities in fully deoxygenated and fully oxygenated environments, respectively.
Compared with tetramethoxysilane (TMOS) and methyltriethoxysilane (MTMS)-derived sensing films, TFP–TriMOS-based sensor exhibited
excellent performances in dissolved oxygen detection with short response time of 4 s, low limit of detection (LOD) of 0.04 ppm
(R.S.D. = 2.5%), linear Stern–Volmer calibration plot from 0 to 40 ppm and long-term stability during the past 10 months.
The reasons for the preferable performances of TFP–TriMOS-based sensing film were discussed. 相似文献
12.
Mauro Tomassetti Riccardo Angeloni Mauro Castrucci Giovanni Visco Luigi Campanella 《International journal of environmental analytical chemistry》2018,98(7):676-684
A basic research has been carried out using four probes to develop an electronic tongue able to discriminate three different kinds of natural waters, i.e. rain, river and groundwater. Several natural water samples were analysed to this purpose using a pH glass electrode, a digital (thermistor) thermometer, an amperometric gaseous diffusion oxygen sensor for measuring the dissolved oxygen and a direct methanol fuel cell enzymatic probe for measuring the concentration of alcoholic traces. Data were processed by means of principal component analysis, obtaining three well differentiated clusters, that demonstrate how the use of only four different sensors can discriminate in an inexpensive and effective way three different classes of natural waters. 相似文献
13.
A prototype respirometric biochip dedicated to monitoring oxygen consumption of preimplantation embryos has been developed. The biochip comprises a linear array of eight flow-through microchambers profiled on silicon substrate, and functions together with a phosphorescent oxygen sensitive probe and fluorescence plate reader detection. A high level of sensitivity to changes in dissolved oxygen was achieved through miniaturisation and optimization of biochip geometry, and incorporation of appropriate sealing and humidification systems. The biochips have allowed characterisation of oxygen consumption, by 2 cell and blastocyst stage preimplantation mouse embryos, through monitoring as few as ten preimplantation embryos over a one-hour time period. They provide a non-invasive, simple and convenient means for assessing preimplantation embryo metabolism. 相似文献
14.
The chelate formed by 8-hydroxy-7-iodo-5-quinolinesulfonic acid (ferron) with aluminium exhibits strong room-temperature phosphorescence (RTP) when retained on a solid support. In a previous paper we have found that sol–gel technology is a very useful approach for developing RTP optical sensors as a new way to immobilize lumiphors. Sol–gel active phases proved to exhibit a high physical rigidity that enhanced relative RTP intensities and triplet lifetimes of the immobilized probe. In this paper we present an optical sensing phase prepared using the Al–ferron chelate which displays RTP entrapped in a sol–gel glass matrix for the determination of very low levels of oxygen both dissolved in water and organic solvents and in gaseous media. The sol–gel sensing material has proved to be chemically stable for at least 6 months under ambient storage conditions. Besides a high reproducibility in the formation of the sensing materials and no leaching or bleaching of the trapped reagent (neither in the gas phase nor in water or organic solvents) was observed. Oxygen was determined by continuous flow and flow injection methods using both intensity and triplet lifetime measurements. Both methods provided a fast response, good reproducibility and detection limits of 0.0005% (v/v) in the gas phase and <0.01 mg l−1 for dissolved oxygen. An exhaustive study of the effect of some possible interferents present in the gas phase or in solution demonstrated the high specificity of this phosphorescent probe. This highly sensitive oxygen probe has been successfully applied to dissolved oxygen determinations in river and tap waters and its coupling to fiber optics for RTP in-situ monitoring or remote sensing of oxygen has been evaluated. 相似文献
15.
《Analytical letters》2012,45(11):2153-2168
ABSTRACT|A simple portable continuous L-lactate monitoring system combining elegant ultrafiltration sample collection and storage with a lactate biosensor has been developed.|The sensor has a detection range from 0.05mM to 30mM lactate dependent on different assignments of the PCS hydrogel complex layer.|The sensor shows excellent performance on sensitivity and validity as well as operational stability over one month.|Samples containing different concentrations of lactate were collected in six hours with an ultrafiltration probe and stored in a 6m long PEEK tube of 125μm in internal diameter.|The ultraslow flow rate of 100 to 350nl/min was controlled by adjusting the restriction in the portable plastic syringe pump and a constant flow can be maintained over 24 hours.|The collected samples were then detected after reversing the flow with a lactate sensor. The total weight of the collection system is only 8g, allowing free movement of the person being tested. 相似文献
16.
Sanam Arami Esmaeel Alipour Mohammad Hossein Pournaghi-Azar Mohammad Saeid Hejazi 《Journal of the Iranian Chemical Society》2013,10(3):399-406
In this study, we developed a new peptide nucleic acid (PNA) biosensor for detection of a single nucleotide polymorphism (SNP) in the UGT1A9 gene promoter region via electrochemical assay. The sensor relies on the immobilization of a 13-mer single stranded PNA probe related to the UGT1A9 gene on the Au electrode (AuE). The hybridization between the probe and its complementary sequence (DcUG275) as the target was studied by differential pulse voltammetry (DPV) of methylene blue (MB) signal. In this approach the extent of hybridization is evaluated on the basis of the difference between DPV signals of MB accumulated on the probe-AuE and MB accumulated on the probe-target-AuE. Some experimental variables affecting the performance of the biosensor including oxygen interference during the assay, probe immobilization time, probe concentration and MB accumulation time were investigated. The PNA probe modified AuE in its optimum condition was shown to be an effective sensor for the detection of hybridization and point mutations. The obtained detection limit of the utilized biosensor has been calculated as 22 nm. 相似文献
17.
A screen-printed dissolved oxygen sensor was fabricated using cerium oxide-supported silver catalyst and polydimethylsiloxane (PDMS) film. A PDMS film of 3 μm thickness showed good permeability for oxygen and impermeability for hydrogen peroxide. The calibration curve has shown a linear relationship with a correlation coefficient of 0.996 for the dissolved oxygen concentration. The sensitivity and detection limit of the present sensor were calculated at -158 μA mM(-1) and 8.4 μM, respectively. 相似文献
18.
Optical fiber sensor using sol gel membrane incorporated RTV silicon rubber was fabricated and developed for the characterization of dissolved oxygen in aqueous solution. The sol gel materials used consists of Tetraethylorthosilicate (TEOS) and Triethoxyoctylsilane (Octyl-triEOS) as the precursor compound for the preparation of the sol gel structures, while tris-BP Ruthenium (II) chloride as the fluorescent lifetime of the oxygen indicator. Dip coating techniques is utilized to position the sol gel technology at the distal end of the optical fiber. Dissolved oxygen gas sensor characterizations include a study on the sensitivity, temperature effects and drift rate of the sensor performance when measured in 40ppt salt water. Potential applications of the optical fiber sensor are including aquaculture, river monitoring and environment sector. 相似文献
19.
基于多孔硅Bragg反射镜的光学免疫检测方法 总被引:2,自引:0,他引:2
通过共价固定方法将羟基红花黄色素A(HSYA)抗血清蛋白固定到多孔硅Bragg反射镜的孔洞中, 定量分析了不同浓度的羟基红花黄色素A人工抗原与特异性抗羟A多克隆抗体反应后多孔硅Bragg反射镜的反射谱峰位的红移情况. 对比研究了固定阴性血清蛋白的多孔硅Bragg反射镜基底在加入抗原后的反射谱峰位变化情况, 结果表明, 基于多孔硅Bragg反射镜的光学免疫检测具有很好的特异性, 且同目前普遍使用的ELISA方法相比, 具有免标记且检测时间短等优异性能, 同时该研究也为开发红花成分快速检测的免标记多孔硅生物传感器奠定了基础. 相似文献
20.
J. Bürck J. -P. Conzen H. -J. Ache 《Fresenius' Journal of Analytical Chemistry》1992,342(4-5):394-400
Summary A fiber optic chemical sensor for determination of organic compounds in aqueous solution has been developed. Based on the evanescent field principle, a quartz glass fiber with a polysiloxane cladding is used as in-situ measuring probe. A compact sensor built from a 6-m coiled fiber has been connected to a commercially available fast scanning dispersive NIR spectrometer. The siloxane cladding fulfils two functions: on the one hand, it acts as protecting layer of the fragile silica fiber core, and on the other hand, it is selective with respect to non-polar organic compounds due to its organophilic properties. Hence, interactions of the evanescent field at the core/cladding interface with organic species penetrating into the cladding can be measured without interferences from broad water OH absorption bands. Aqueous solutions of chlorinated hydrocarbon solvents (CHS) have been used to test the sensor response. NIR evanescent field absorbance spectra of methylene chloride, chloroform and trichloroethylene diffused into the fiber cladding are shown in the 900–2100 nm spectral range. Different amounts of CHCl3 dissolved in water have been determined in order to evaluate the quantitative sensor response. A linear absorbance/concentration relationship has been found for solutions between 80–6800 mg l–1. Kinetic experiments performed with CHCl3 solutions resulted in sensor response times of 5–10 min. The sensor seems to be promising for the remote monitoring of organic contaminants, e.g. CHS, in drainage waters of contaminated areas. 相似文献