This PDF file contains the front matter associated with SPIE Proceedings Volume 7673, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

Despite the recent interest in organically grown foods, most agricultural crops use multiple pesticides to optimize yield. There are many persons whose health may be affected by the spraying; there is the active applicator and the passive neighbors. In between these extremes are the farm workers who pick the crops anywhere from days to weeks after application. How much pesticide residue are these workers exposed to during a workday and how much is transferred back to the residence? Despite the low vapor pressures, what is the true concentration of pesticides surrounding a person when pesticides adsorbed to particulate matter are included? What is the relationship between the concentration around an individual and the amount adsorbed/ingested? To answer these questions on a statistically significant scale in actual field conditions, a portable, fast, inexpensive measurement device is required. We present herein results obtained using Surface-Enhanced Raman Spectroscopy (SERS) that demonstrate the capability to detect < 100 organophosphate, organochlorine and carbamate-based pesticides in the vapor phase as well as the ability of SERS sensors to detect a particular analyte in a synthetic urine matrix. We will also present data collected from CDC quantified urine samples and will present results obtained in a field test wherein SERS sensors wore worn as dosimeters in the field and real-time vapor sampling of the farm workers barracks was performed. The issue of potential interferences will also be discussed.

In this paper we present a quick and easy method for producing relatively large areas of nanostructured substrate that enhances the Raman effect. Standard semiconductor processing techniques are used, hence it is possible to narrowly control the parameters of the fabrication process to create free standing silicon nanopillars with controlled aspect ratios and spacing. The silicon nanopillars are coated by thin films of silver and/or gold to create Raman active surfaces. Surface enhanced Raman scattering (SERS) spectroscopy has numerous applications in chemical sensing, with high sensitivity and fast analysis speed seen as the main advantages. We show how these novel substrates can be used in an explosives sensor. Under the framework of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these SERS substrates coupled with commercially available microspectrometers will be included in handheld explosives detectors with applications in homeland security and landmine clearance.

The ability to detect high explosive compounds is a fundamental step in achieving the goal of creating devices capable of 'sniffing' out explosive devices. To detect high explosive compounds such as 2,4,6-trinitrotoluene (TNT), a molecularly imprinted polymer (MIP) sensor was developed. This sensor consists of MIP microspheres prepared using methacrylic acid as the functional monomer in a precipitation polymerization reaction. The MIP microspheres are then combined with fluorescent semiconductor nanocrystals, or quantum dots, via a simple crosslinking procedure. To study the sensor's ability to detect nitroaromatic analytes, the fluorescent-labeled MIP particles were exposed to aqueous 2,4- dinitrotoluene (DNT), a nitroaromatic molecule very similar to TNT. Characterization of the MIP particles shows a uniform size distribution, with an average diameter of approximately 615 nm. Imaging of the particles also shows that spherical shapes are being produced by the precipitation polymerization reaction. Preliminary data indicate that the sensor is capable of detecting nitroaromatic compounds in an aqueous solution. These results illustrate the future application of the fluorescent-labeled MIP sensor for detecting high explosives, with the potential for use in detecting vapors from explosive devices and in an array of environmental conditions.

A Surface Plasmon Resonance (SPR) biosensor that operates deep into the infrared (3-11 μm wavelengths) is potentially capable of biomolecule recognition based both on selective binding and on characteristic vibrational modes. A goal is to operate specifically at wavelengths where biological analytes are strongly differentiated by their IR absorption spectra and where the refractive index is increased by dispersion. This will provide enhanced sensitivity and selectivity, when biological analytes bind reversibly to biomolecular recognition elements attached to the sensor surface. This paper describes work on the optical and materials aspects of IR surface plasmon resonances. First, three possible coupling schemes are considered: hemicylindrical prisms, triangular prisms, and gratings. Second, materials with plasma frequencies one order of magnitude smaller than for noble metals are considered, including doped semiconductors and semimetals.

A tapered optical fiber sensor (TOFS) is a kind of optical fiber sensor that uses special geometries to measure properties of surrounding environments or samples using evanescent waves. This paper presents a fast, highly sensitive, and inexpensive tapered optical fiber biosensor that, using a miniature sensing structure, enables the label-free direct detection of biomolecules. The sensor takes advantage of the interference effect between the fiber's first two modes along the taper waist region. This effect causes some interference fringes in the transmission spectrum. Because of its sharp spectrum fringe signals and its long biomolecule testing region, the sensor is fast and highly sensitive. To better understand the influence of various biomolecules on the sensor, a computer simulation that varied such bio-layer parameters as thickness and refractive index was performed. The result of 0.4 nm/nm showed that the spectrum fringe shift of the sensor was large enough to be easily measured even when the bio-layer was nanometers thick. A tapered optical fiber biosensor was then fabricated and evaluated with an immune globulin G (IgG) antibody-antigen pair, and showed good performance.

There is a growing need for miniature low-cost chemical sensors in monitoring environmental conditions. Applications range from environmental pollution monitoring, industrial process control and homeland security threat detection to biomedical diagnostics. Integrated opto-electronic sensors can provide chemical & biological sensing by monitoring attachment induced changes in the refractive, absorptive, or luminescent properties of materials. Nanomembranes (NMs) are single crystals that have been released from SOI substrates and redeposited on foreign flexible or flat substrates enabling the best features of different materials. Silicon Nanomembrane technology can enable the fabrication of compact, replaceable/disposable and highly sensitive optoelectronic sensors for chemical and biological sensing.

This paper presents the analytical performances of an AlGaN/GaN High Electron Mobility Transistor (HEMT) based sensor for the detection of H2 gas. The model calculates the changes in drain-to-source current and sensitivity of the device due to adsorbed atomic density of gas at the gate terminal. Simulated results indicate that AlGaN/GaN HEMT based floating gate sensors are highly suitable for the extreme environment detection of various gases with concentration as low as ~ ppb level.

Raman spectroscopy is a powerful tool to obtain "fingerprint" spectra from substances in numerous applications. In-situ and/or real time measurements are interesting for the detection of minerals, organic compounds, gas hydrates or methane in the deep-ocean. In this work we present Raman measurements of selected minerals. A DFB diode laser at 785 nm was used as excitation light source with an output power up to 1.5 W. An excitation fiber of 1000 m length was used to demonstrate the suitability of Raman spectroscopy for deep-sea applications.

We demonstrate the rapid detection of explosive vapors based on a fiber-based optical Fabry-Pérot (FP) gas sensor. The sensing probe of the FP sensor is composed of a thin metal layer and a vapor-sensitive polymer layer that are deposited sequentially on a cleaved fiber endface to form an FP cavity. The interference spectrum generated from the reflected light at the metal-polymer and polymer-air interfaces changes upon the absorption of gas analyte. By monitoring the interference shift, we are able to obtain quantitative and knetic information of the interaction between the analyte and the polymer layer. We further assemble the FP sensor with a short fused silica capillary into a sensor module, and employ it in a gas chromotgraphy (GC) system for selevtive rapid on-column detection. In this report, we specifically target 2, 4- dinitrotoluene (DNT) and 2, 4, 6-trinitrotoluene (TNT) for their obvious defense applications. This work could lead to a portable sensor capable of detecting low concentrations of DNT, TNT, and other explosive chemicals.

This paper addresses the question of what contributions the International Space Station (ISS) can make as a sensor based remote sensing platform. There is precedent for the use of manned platforms in Low Earth Orbit (LEO). Skylab had the Earth Resources Experiment Package (EREP). In the Shuttle -Mir program, the Piroda module was dedicated to Earth sensing. One experiment in the Piroda, the Multispectral Stereo Scanner (MOMS-2PP) was used for quantifying the advantages of performing remote sensing on the ISS. The Space Shuttle program also made significant contributions to Earth observations. Sixteen missions carried electronic experiment packages for Earth observations and crew on almost every mission performed earth observations using cameras. Experiments planned for the ISS can also tell us much about the potential the ISS has as a remote sensing platform by examining their design and objectives. In March of 2009 an experiment called Agricultural Camera (AgCam) was delivered to the ISS for installation in the window of the Laboratory module. In fall of 2009 two more remote sensing experiments will arrive on the ISS - the Hyperspectral Imager for the Coastal Ocean (HICO) and the Remote Atmospheric and Ionospheric Detection System (RAIDS). These instruments will be combined on one experiment package, HICO- RAIDS experiment package (HREP), and will be placed outside the ISS, on an external platform.

In recent years open-path FTIR systems (active and passive) have demonstrated great potential and success for monitoring air pollution, industrial stack emissions, and trace gas constituents in the atmosphere. However, most of the studies were focused mainly on monitoring gaseous species and very few studies have investigated the feasibility of detecting bio-aerosols and dust by passive open-path FTIR measurements. The goal of the present study was to test the feasibility of detecting a cloud of toxic aerosols by a passive mode open-path FTIR. More specifically, we are focusing on the detection of toxic organophosphorous nerve agents for which we use Tri-2-ethyl-hexyl-phosphate as a model compound. We have determined the compounds' optical properties, which were needed for the radiative calculations, using a procedure developed in our laboratory. In addition, measurements of the aerosol size distribution in an airborne cloud were performed, which provided the additional input required for the radiative transfer model. This allowed simulation of the radiance signal that would be measured by the FTIR instrument and hence estimation of the detection limit of such a cloud. Preliminary outdoor measurements have demonstrated the possibility of detecting such a cloud using two detection methods. However, even in a simple case consisting of the detection of a pure airborne cloud, detection is not straightforward and reliable identification of the compound would require more advanced methods than simple correlation with spectral library.

Benefiting from the rich amount of information provided by a hyperspectral imager such as an imaging Fourier-transform spectrometer, we developed a suite of gas quantification algorithms that were applied to identify the gas released by distant stacks, and to quantify their specific mass flow rates. The method successfully performs the gas quantification through a range of important radiometric and instrumental considerations. Interactions between the released gases and the fluctuating winds result in strong turbulences which are accounted for by a recently developed algorithm avoiding scene change artifacts, thus ensuring valid estimation of the spectral radiance emitted by the plume.

In the framework of the research project 'Xsense' at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT and TNT, and identification of volatile organic compounds in the presence of water vapor in air. The technology is based on an array of chemo-responsive dyes immobilized on a solid support. Upon exposure to the analyte in suspicion the dye array changes color. Each chosen dye reacts chemo selectively with analytes of interest. A change in a color signature indicates the presence of unknown explosives and volatile organic compounds (VOCs). We are working towards the selection of dyes that undergo color changes in the presence of explosives and VOCs, as well as the development of an immobilization method for the molecules. Digital imaging of the dye array before and after exposure to the analytes creates a color difference map which gives a unique fingerprint for each explosive and volatile organic compound. Such sensing technology can be used to screen for relevant explosives in a complex background as well as to distinguish mixtures of volatile organic compounds distributed in gas phase. This sensor array is inexpensive, and can potentially be produced as single use disposable.

Regional difference of environmental evolvements is one of important aspects in world change research program. Changes in land cover and in the way people use the land have become recognized as important global environmental change in many areas. Land-use and cover changing (LUCC) is one of the major studies of global changing lately. Land-use is the term which covers the condition of used-land, the method, extent, structure, regional distributing and benefits in the land-use. It is affected by the natural condition or is enslaved to the conditions in society, economy and technology, and social production mode plays a decisive role in land-use; land-cover is the state of covering which is formed on account of the earth's surface or contrived by human being, is the summary of vegetation and artificially covering on the earth's surface. So land-use and cover changing is connecting closely. Land-use and cover changing information points that information on the position, distributing, range, and size of land-use and cover changing in the certain time. Motivated by a global concern for sustainability and environmental quality in city, a considerable number of studies have utilized satellite sensor data in the analysis of urban morphological change .some studies focused on the physical and socioeconomic drivers of change in urban land cover and implications on land use practices and resource management. Other studies went beyond the characterization of change and its causes and attempted to integrate remotely sensed data with models of urban growth to project future change. GIS and RS technologies are widely applied for LUCC studies providing a powerful tool for capturing, storing, checking manipulating, merging, analyzing and displaying data. Especially RS technology are also widely used for LUCC studies such as automatic discovery changing, automatic extraction changing area, confirmation changing type, using interactive explanation accessorily to extract the changing information of land-use in the research area. RS has an important contribution to make in the actual change in LUCC on regional. This paper studies land-use and land-cover change in Fuzhou area of Fujian Province, China. It builds a series of land-use change maps using Remote Sensing automatic monitoring and GIS spatial analysis techniques. Finally the paper briefly discusses the drive of land-use and cover changes. The study provides a reference to the sustainable development for the region.

Raman spectroscopy is a technology that can detect and distinguish materials based on the materials' Raman scattering. However, the signal produced using this technology is usually too small to be useful. The Raman spectrum signal can be enhanced by creating rough patches on the surface of the material. In this paper, a novel method to produce nanometer-sized features on optical materials such as glass, fused silica, and quartz substrate is presented. Using a femtosecond laser, the transparent materials are sputtered and deposited. When the materials cool down, they produce structures with nano-features. These nano-features on optical materials can make designing optical sensing systems much easier. Scanning electron microscope photos of nano-structures on quartz substrate and optical fiber show that features less than 100 nm in size have been successfully fabricated. The 3D micro- and nano-structures of the sensor were studied using a confocal Raman spectrum microscope and focused ion-beam milling. Raman spectrum signals show that the strength of the signal generated by Raman scattering was greatly enhanced compared to substrates without nano-features.

A series of nanocrystal and nanocrystal quantum dot taggant technologies were developed for covertly tagging and tracking objects of interest. Homogeneous and heterogeneous nanocrystal taggant designs were developed and optimized for ultraviolet through infrared emissions, utilizing either Dexter energy transfer or Förster resonant energy transfer (FRET) between specific absorbing and emitting functionalities. The conversion efficiency, target-specific identification, and adhesion properties of the taggants were engineered by means of various surface ligand chemistries. The ability to engineer poly-functional ligands was shown effective in the detection of a biological agent simulant, detected through a NC photoluminescence that is altered in the presence of the agent of interest; the technique has broad potential applicability to chemical, biological, and explosive (CBE) agent detection. The NC photoluminescence can be detected by a remote LIDAR system; the performance of a taggant system has been modeled and subsequently verified in a series of controlled field tests. LIDAR detection of visible-emitting taggants was shown to exceed 2.8 km in calibrated field tests, and from these field data and calibrated laboratory measurements we predict >5 km range in the covert shortwavelength infrared (SWIR) spectral region.

Experimental results in shifted excitation resonance Raman difference spectroscopy (SERRDS) at 488 nm will be presented. A novel compact diode laser system was used as excitation light source. The device is based on a distributed feedback (DFB) diode laser as a pump light source and a nonlinear frequency doubling using a periodically poled lithium niobate (PPLN) waveguide crystal. All elements including micro-optics are fixed on a micro-optical bench with a footprint of 25 mm × 5 mm. An easy temperature management of the DFB laser and the crystal was used for wavelength tuning. The second harmonic generation (SHG) provides an additional suppression of the spontaneous emission. Raman spectra of polystyrene demonstrate that no laser bandpass filter is needed for the Raman experiments. Resonance-Raman spectra of the restricted food colorant Tartrazine (FD&C Yellow 5, E 102) in distilled water excited at 488 nm demonstrate the suitability of this light source for SERRDS. A limit of detection (LOD) of 0.4 μmol·l^-1 of E102 enables SERRDS at 488 nm for trace detection in e.g. food safety control as an appropriate contactless spectroscopic technique.

At last meeting, we reported a new type of surface-enhanced Raman Spectroscopy (SERS) substrates based on metal (Au or Ag) coated Si nanocones fabricated by a Bosch etching process. The substrate showed reliable SERS performance with an analytical enhancement factor greater than 6 × 10⁷ for trans-1,2-bis(4-pyridyl)-ethylene (BPE) molecules. However, the process is limited to single crystalline silicon material, also silicon can absorb both incident and scattered light, making it difficult to investigate the SERS enhancement mechanism. To further improve the sensitivity of the SERS substrate, we have recently developed a process to duplicate the Si nanocones by a cross-linked polymer using 3-D nanoimprint lithography (NIL). The SERS substrate made by NIL demonstrated better enhancement factors for both 633 nm excitation and 785 nm excitation with analytical enhancement factors of over 10¹¹ demonstrated. We will report the rational engineering of the nanocone based SERS substrate and the fundamental understanding of the enhancement mechanism.

This paper reports the development of a hydrazine fiber optic reversible sensor that operates, for the first time to our knowledge, in the lowest attenuation wavelength range of commercial silica fibers. A pentacenediquinone (PDQ) and polymer mix, with an index of refraction adjusted to closely match that of silica, was used as an active sensing material replacing the cladding of a silica core optical fiber. The optical signal passing through this modified cladding type fiber sensor exhibited a reversible intensity change in the presence hydrazine at different concentrations.

In the frame of biological threat, security systems require label free biochips for rapid detection. Biosensors enable to detect biological interactions, between probes localized at the surface of a chip, and targets present in the sample solution. Here, we present an optical transduction, enabling 2D imaging, and consequently parallel detection of several reactions. It is based on the absorption of biological molecules in the UV domain. Thus, it is based on an intrinsic property of biological molecules and does not require any labelling of the biological molecules. DNA and proteins absorb UV light at 260 and 280 nm respectively. Sensitivity is a major requirement of biosensing devices. Configurations leading to enhancement of the interaction between light and biological molecules are of interest. For a better sensitivity, resonant grating structures are then studied. They enable to confine the electric field close to the biological layer. Imaging of resonant grating is not largely studied, even for visible wavelengths, but it results in good sensitivity. The protein used in this study is the methionyl-tRNA synthetase. Its absorption is representative of protein absorption, and it can then serve as a model for immunological detection. The best experimental contrast due to a monolayer of proteins is 40%. With data processing currently employed for biochip imaging: average on several acquisitions and on all the pixels imaging the biological spots, the device is able to detect a surface density of proteins in the 10 pg/mm range.

In some countries it is common to have wooden structures in their homes, especially Japan. However, metals and its alloys are the most widely used engineering materials in construction of any military or civil structure. Re-visiting natural disasters like the recent Haiti earthquake (12 Jan 2010) or Katrina (cyclones) reminds the necessity to have better housing infrastructure with robust monitoring systems. Traditionally wood (green material) was accepted as excellent rehabilitation material, after any disaster. In recent times, the recycling materials extracted from inorganic, biodegradable wastes are converted into blocks or sheets, and are also used to assist public in rehabilitation camps. The key issue which decreases the life of these rehabilitated structure including green materials (like wood) is unnecessary degradation or deterioration over time due to insect or acid attack or rain/ice fall. The recycling material also needs monitoring to protect them against acid or rain/ice attacks. Thus, a few health monitoring techniques have emerged in the recent past. Electromechanical Impedance technique is one such technique, which is simple but robust to detect variations in the integrity of structures. In this paper, impedance based piezoceramic sensor was bonded on wooden sample, which was subjected to degradation in presence of acids. Variations in mass of plank are studied.

Indentifying and quantifying ambient aerosols are important for air-quality applications. Unlike trace gases where chemical spectral signatures are sharp and well defined, aerosol spectral signatures are broader and highly overlapping. Therefore separation of aerosols into different size classes requires very broad spectral coverage from the visible (VIS) to mid-infrared (MIR). In this paper, we investigate the feasibility in using a VIS (0.65μm) diode laser combined with a suitable pulsed high power Quantum Cascade Laser (4.6μm) to obtain backscatter measurements that can be used to isolate fine and coarse mode aerosol fractions. Based on realistic source characteristics, we study the information content in the spectral extinction using different combinations of extinction measurements using Least Squares Minimization applied to a wide range of aerosol multimode mixtures obtained using realistic models obtained from the Optical Properties of Aerosol and Clouds (OPAC) model. This model is especially convenient since the optical spectral extinction and backscatter spectra are evaluated over a wide wavelength range from 250nm to 40μm. In particular, we find that with the latest QCL systems, it is possible to achieve signal to noise ratio (SNR) values ~10 with suitable temporal and spatial averaging for aerosol layers ~1.5km making it suitable for PBL layer studies.

Polymerase chain reaction (PCR) is a common method used to create copies of a specific target region of a DNA sequence and to produce large quantities of DNA. A few DNA molecules, which act as templates, are rapidly amplified by PCR into many billions of copies. PCR is a key technology in genome-based biological analysis, revolutionizing many life science fields such as medical diagnostics, food safety monitoring, and countermeasures against bioterrorism. Thus, many applications have been developed with the thermal cycling. For these PCR applications, one of the most important key factors is reduction in the data acquisition time. To reduce the acquisition time, it is necessary to decrease the temperature transition time between the high and low ends as much as possible. We have developed a novel rapid real-time PCR system based on rapid exchange of media maintained at different temperatures. This system consists of two thermal reservoirs and a reaction chamber for PCR observation. The temperature transition was achieved within 0.3 sec, and good thermal stability was achieved during thermal cycling with rapid exchange of circulating media. This system allows rigorous optimization of the temperatures required for each stage of the PCR processes. Resulting amplicons were confirmed by electrophoresis. Using the system, rapid DNA amplification was accomplished within 3.5 min, including initial heating and complete 50 PCR cycles. It clearly shows that the device could allow us faster temperature switching than the conventional conduction-based heating systems based on Peltier heating/cooling.

In countries like USA or Japan it is not so uncommon to have wooden structures in their homes. However, metals and its alloys are the most widely used engineering materials in construction of any military or civil structure. Revisiting natural disasters like the recent Haiti earthquake (12 Jan 2010) or Katrina (cyclones) reminds the necessity to have better housing infrastructure with robust monitoring systems. Traditionally wood is accepted as excellent rehabilitation material, after any disaster. The recycling materials extracted from in-organic, biodegradable wastes, also can be used for rehabilitation. The key issue which dampens the life of these rehabilitated structure including green materials (like wood) is unnecessary deposits (nails, screws, bolts etc)/damages due to insect attack. Thus, a few health monitoring techniques have emerged in the recent past. Electromechanical Impedance technique is one such technique, which is simple but robust to detect variations in the integrity of structures. In this paper, impedance based piezoceramic sensor was bonded on wooden sample, which was used to study changes due to metallic (steel nails) deposits at various locations. A study of weight deposits on aluminum plate was used for comparisons.

In this paper, a new complex sensing film containing both optical indicator and enzyme was prepared and its sensing properties were studied, using cellulose acetate (CA) as the carrier and tris (2,2'-blpyridyl) dichloro-ruthenium (II) hexahydrate (Ru(bpy)₃Cl₂) as the indicator. The cross-linking method was used to immobilize glucose oxidase (GOD). The immobilization conditions were optimized: the concentration of sodium periodate as 0.2 M and the reaction time as 30 min, those for ethanediamine as 0.03 M and 2.5 hours, those for GA as 1.5% (v/v) and 2 hours, those for GOD as 35 mg/ml and 21h. The optimal temperature and pH value for the catalytic properties of the sensing film are 38 °C and 7.0, respectively. A fiber optic glucose sensor with this complex sensing film has been studied. The results show that its detecting range is 100-600 mg/dl and its response time is less than 20 seconds.

We report simultaneous salinity/saccharinity and temperature measurement with a fiber Bragg grating (FBG)-based sensor system. By adopting multiplexing technique, the sensor system consists of two FBG sensing elements in which one FBG is sensitive to salinity/saccharinity while the other one sensitive to temperature only. Experiments indicated that the salinity, saccharinity, and temperature sensitivities of the polyimide-coated grating were 0.0165 nm/M (blueshift), 0.0012 nm/°Bx (blueshift), and 0.0094 nm/°C (redshift), respectively. The temperature sensitivity of the acrylate-coated FBG was 0.0102 nm/°C (redshift).

A novel fiber optic biosensor for the determination of nitric oxide based on vicinal diaminobenzozcridine (VDABA) fluorescent probe was designed and fabricated. The reaction conditions between VDABA and NO, which include concentration of VDABA, temperature and pH, were studied in-depth. The sensitivity of VDABA for NO detection under the optimum conditions and its optical properties were also investigated. The fluorescence responses were concentration-dependent and a good linear relationship (R²=0.9863) was observed over the range 1.8×10^-6 to 9×10^-6 mol/L NO, the regression equation was F = 3.8889[NO] (mol/L)+217.2. Besides, a complex sensitive film embedding VDABA in cellulose acetate (CA) was prepared, and a fiber optic NO biosensor was fabricated using this film. Then the change of fluorescence phase shift of this biosensor was studied preliminarily by means of the lock-in technology.

In this paper, Glucose oxidase (GOD) was immobilized on a novel silica membrane. The multifunctional sensing membrane was prepared by sol-gel method. GOD was immobilized on the aminated silica surfaces by glutaraldehyde cross-linking method. The fiber optical glucose sensor based on fluorescence quenching was designed and fabricated using lock-in amplifying technology to realize the detection of glucose concentration. The experimental results show that a linear range between phase delay φ and the glucose concentration of the solution was observed in the concentration range of 100 to 600 mg/dl and the detection limit is 50mg/dl, the sensor can meet the demand of clinical application. The response time of the sensing membrane was about 15s. The experimental results demonstrated that this biosensor with the multifunctional sensing membranes has high sensitivity, repeatability, good stability and fast response.