Optical fiber humidity sensor based on a tapered fiber coated with agarose gel

Cooper

2008

J. Lightwave Technol.

DNA detection technology has developed rapidly due to its extensive application in clinical diagnostics, bioengineering, environmental monitoring, and food science areas.Currently developed methods such as surface Plasmon resonance (SPR) methods, fluorescent dye labeled methods and electrochemical methods, usually have the problems of bulky size, high equipment cost and time-consuming algorithms, so limiting their application for in vivo detection. In this work, an intrinsic Fabry-Perot interferometric (IFPI) based DNA sensor is presented with the intrinsic advantages of small size, low cost and corrosion-tolerance. This sensor has experimentally demonstrated its high sensitivity and selectivity.In theory, DNA detection is realized by interrogating the sensor's optical cavity length variation resulting from hybridization event. First, a microgap structure based IFPI sensor is fabricated with simple etching and splicing technology. Subsequently, considering the sugar phosphate backbone of DNA, layer-by-layer electrostatic self-assembly technique is adopted to attach the single strand capture DNA to the sensor endface. When the target DNA strand binds to the single-stranded DNA successfully, the optical cavity length of sensor will be increased. Finally, by demodulating the sensor spectrum, DNA hybridization event can be judged qualitatively.This sensor can realize DNA detection without attached label, which save the experiment expense and time. Also the hybridization detection is finished within a few minutes.This quick response feature makes it more attractive in diagnose application. Since the iii sensitivity and specificity are the most widely used statistics to describe a diagnostic test, so these characteristics are used to evaluate this biosensor. Experimental results demonstrate that this sensor has a sensitivity of 6nmol/ml and can identify a 2 bp mismatch. Since this sensor is optical fiber based, it has robust structure and small size ( 125μm ). If extra etching process is applied to the sensor, the size can be further reduced. This promises the sensor potential application of in-cell detection. Further investigation can be focused on the nanofabrication of this DNA sensor, and this is very meaningful topic not only for diagnostic test but also in many other applications such as food industry, environment monitoring.iv Acknowledgement

Section: Factors Controlling the Polymer Growthmentioning

confidence: 99%

Microgap Structured Optical Sensor for Fast Label-Free DNA Detection

Cooper

2008

J. Lightwave Technol.

Materials Science-Poland

“…Recently, quantum dots embedded coating on optical fibers have been developed to detect gases [1,2], pH [3], temperature [4], humidity [5,6] and bimolecules [7,8]. There are various schemes described in literature, for optical fiber sensors such as Bent optical fiber sensor [9], tapered optical fiber sensors and cladding removed optical fiber sensor [10].…”

Section: Introductionmentioning

confidence: 99%

Sensing application of an optical fiber dip coated with L-Cystein ethyl ester hydrochloride capped ZnTe quantum dots

Sundaray

Das

Tripathy

2016

Optical fiber in conjunction with ZnTe quantum dots (QDs) is investigated for sensing application. ZnTe QDs, are synthesized by a simple chemical bottom up approach. Quantum dots are capped with L-Cystein ethyl ester hydrochloride (LEEH), to increase their stability. Then LEEH capped ZnTe QDs, whose size is estimated as 2.29 nm by effective mass approximation (EMA), are dip-coated on a cladding removed optical fiber. Different concentrations of alcohol and ammonia are used to investigate the sensing behavior. It is found that sensitivity of the sensor increases with the use of QDs for both alcohol and ammonia.

“…Owing to the unique mechanical and structural properties of silicon, silicon-based micromechanical transducers and sensors are widely used in a number of applications, including the sensing of temperature and humidity, [1][2][3][4] pressure, 5,6 inertia 7 and acceleration [8][9][10] and the motion of a moving track. 11 State-of-the-art microfabricated accelerometers have undergone a number of advances.…”

Section: Introductionmentioning

confidence: 99%

Frontside-micromachined planar piezoresistive vibration sensor: Evaluating performance in the low frequency test range

Zhang

Takagi

et al. 2014

AIP Advances

Articles you may be interested inUsing a surface piezoresistor diffusion method and front-side only micromachining process, a planar piezoresistive vibration sensor was successfully developed with a simple structure, lower processing cost and fewer packaging difficulties. The vibration sensor had a large sector proof mass attached to a narrow flexure. Optimization of the boron diffusion piezoresistor placed on the edge of the narrow flexure greatly improved the sensitivity. Planar vibration sensors were fabricated and measured in order to analyze the effects of the sensor dimensions on performance, including the values of flexure width and the included angle of the sector. Sensitivities of fabricated planar sensors of 0.09-0.46 mV/V/g were measured up to a test frequency of 60 Hz. The sensor functioned at low voltages (<3 V) and currents (<1 mA) with a high sensitivity and low drift. At low background noise levels, the sensor had performance comparable to a commercial device. C 2014 Author(s)