DOCSLIB.ORG

Comparison of Colorimetric, Fluorescence and Luminescence Analysis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Comparison of Colorimetric, Fluorescence and Luminescence Analysis www.aladdin-e.com Comparison of colorimetric, fluorescence and luminescence analysis Introduction 25°C, and 37°C, Over the years, the enzyme immunoassay that greater than six months shelf life when stored Engvall and Perlmann first described has taken at 4°C, many different forms. Today there are commercially available, heterogeneous, homogeneous, cell-based, capable of being conjugated to an antigen or colorimetric, fluorescent and luminescent, to antibody, name just a few, versions of the original ELISA. inexpensive, They all have antibody-antigen complexes and easily measurable activity, enzyme reactions in common. In this technical high substrate turnover number, bulletin, we here will focus on the enzyme linked unaffected by biological components of the immunosorbent assay and discuss three types of assay. detection systems — colorimetric, fluorescent, and luminescent. By far, the two most popular enzymes are All ELISA, regardless of the detection system peroxidase and alkaline phosphatase. Each has employed, require the immobilization of an their advantages and disadvantages. Both are antigen or antibody to a surface. They also quite stable when handled and stored properly, require the use of an appropriate enzyme label and both can be stored at 4°C for greater than 6 and a matching substrate that is suitable for the months. Both are also commercially available as detection system being used. Associated with the free enzymes and as enzyme conjugates (enzyme enzyme-substrate reaction are several labeled antibodies, etc.) and are relatively requirements, such as timing and development inexpensive. However, there are some differences conditions, that need to be optimized to result in between these two enzymes that should be a precise, accurate and reproducible assay. considered when choosing one for an assay. Colorimetric Assays Peroxidase is a small molecule (MW~40,000) that Colorimetric assays result in a colored reaction can usually be conjugated to an antibody in a 4:1 product that absorbs light in the visible range. ratio. Due to its small size, it rarely causes steric The optical density of the reaction product is hindrance problems with antibody/antigen typically proportional to the amount of analyte complexes bound on a surface. Peroxidase is very being measured. inexpensive compared to alkaline phosphatase. Selecting the Appropriate Enzyme Label Several substrates, yielding either soluble or The most common enzymes used as labels for insoluble reaction products, are commercially ELISA are 1) horseradish peroxidase, 2) calf available for per- oxidase. Since all peroxidase intestine alkaline phosphatase, and 3) E. coli ß- reactions require hydrogen peroxide, purchasing D-galactosidase. These enzymes are typically commercially available substrates is used because they each meet most, if not all, of recommended because these preparations contain the cri- teria necessary to produce a sensitive, stabilized hydrogen peroxide which adds to their inexpensive, and easily performed assay. value and usefulness. These criteria include: stability at typical assay temperatures: 4°C, 1 www.aladdin-e.com The major disadvantage associated with is most likely the reason why it is the least peroxidase is that it is incompatible with many popular. For unexplained reasons, ß- preservatives, such as sodium azide, that are galactosidase also suffers from antibody-induced used to reduce microbial contamination in many inhibition. An advantage of ß-galactosidase is its biological buffer solutions. Sodium azide, even in enhanced reaction rate in the presence of low concentrations, inactivates peroxidase alcohols, which lends itself as a suitable enzyme activity. Other compounds or elements that for assays performed on hydrophobic membrane interfere with peroxidase activity are metals surfaces (i.e., dot blot applications) that require found in water and endogenous peroxidases alcohol to wet out. found in biological specimens. These disadvantages can be overcome by using sterile For colorimetric assays, either alkaline buffers without preservatives, using reagent phosphatase or peroxidase is a suitable enzyme. grade type II water, and pretreating specimens Both enzymes have a wide range of substrates suspected of having high peroxidase levels with that yield qualitative and quantitative results. hydrogen peroxide prior to use in an assay. Typically, non- bound biological components are Selecting a Suitable Substrate washed away prior to the addition of the enzyme, For all enzyme-linked immunoassays, the final so endogenous peroxidase activity is usually not stage is the addition of the enzyme substrate. an issue. The substrate is chosen for its quantitative yield of a colored, fluorescent or luminescent reaction Alkaline phosphatase is approximately double product. For colorimetric assays the rate of color the size of peroxidase (MW ~86,000). This development is proportional, over a certain means that one will typically see a lower enzyme range, to the amount of enzyme conjugate to antibody conjugation ratio. It also means that present. the larger molecular size of alkaline phosphatase can cause steric hindrance issues due to close A suitable substrate must be chosen to meet the packed antigen-antibody complexes. This can assay requirements of the assay being result in lower activity than expected for the performed. Substrates can produce either estimated number of bound enzyme molecules insoluble or soluble colored reaction products. (which is sometimes considered responsible for Typically, insoluble reaction products are desired the “high dose hook” phenomenon). Alkaline for membrane-based assays, such as dot blots. phosphatase is slightly more expensive than An insoluble colored dot is produced at the site of peroxidase, but is considered to be more stable. the reaction. Along with being a visual and Substrates for alkaline phosphatase range from sometimes permanent record, the intensity of the soluble to insoluble; many can be signal colored product can be measured using enhanced to increase sensitivity. densitometry. However, insoluble reaction products are not practical for solution The major disadvantage associated with using immunoassays performed in multiple well assay alkaline phosphatase is that it is inactivated by plates. Substrates that form soluble reaction chelating agents, acidic pH (< 4.5), or inorganic products are better suited for ELISA. phosphates. This means that buffers must be specific for alkaline phosphatase, and one cannot Both peroxidase and alkaline phosphatase have use standard assay phosphate buffered saline substrates that yield soluble colored reaction solutions as diluents or wash solutions that come products. The decision as to which substrate is in contact with the enzyme during an assay. the best for any type of assay depends on the However, chelators (EDTA) and acidic pH are sensitivity desired, the timing requirements, and typically used as convenient and inexpensive the detection device to be used. For assays that stopping reagents for alkaline phosphatase need to be very sensitive (able to detect low reactions. amounts of analyte), the most desirable substrates produce intensely colored reaction ß-galactosidase is the least used of the three products at very fast reaction rates. For assays top enzymes for ELISA. This enzyme is quite that require a large dynamic range (typical large; its four subunits combined have a analyte amounts span a wide range of molecular weight of greater than 300,000. Its size 2 www.aladdin-e.com concentrations), substrates that produce reaction less sensitive than TMB. Its reaction product is product over a long time (15 to 30 minutes) and yellow and can be read at 490 nm. result in a broad range of analyte- dependent color intensities are the most desirable. For Alkaline phosphatase: The most common assays with a timed end- point, a chemical substrate that produces an insoluble reaction inhibitor is added to the reaction after a defined product is BCIP/NBT (5-bromo-4-chloro-3-indolyl- time that stops further color development. phosphate/nitroblue tetrazolium). It is recognized This allows detection to be performed within a as the most effective substrate for immunoblots reasonable time; for this, a substrate that has a due to its stability and resistance to fading when “slow” reaction rate (15 to 30 minutes to exposed to light. The most widely used substrate completion) is optimal. This “slow” reaction rate that produces a soluble reaction product is p- allows the technician (or automated equipment) NPP (p-nitro- phenylphosphate). It produces an to start the reaction and stop the reaction at a intense yellow color measurable at 405 to 410 reasonable pace. However, when kinetic analysis nm. An advantage of this substrate is that it can of the enzyme-substrate reaction is used, a be allowed to develop for extended periods to substrate that has a “fast” reaction rate (5 obtain a corresponding increase in sensitivity. minutes or less) should be used. In this case, the Normally p-NPP has a slow reaction rate which substrate is added, and the rate of conversion of should be allowed 30 to 60 minutes to reach substrate to colored reaction product is optimal color development before being stopped immediately measured. The reaction is usually with 1N NaOH. It is not recommended for kinetic measured over discreet and short time intervals analysis. (i.e., 10 seconds) for 2 to 5 minutes. Reaction Requirements The following are the most commonly used Many factors affect
Load more

Recommended publications
  • LED Retrofit Headlamp Light Sources Ensure Legal Access to the German Automotive Market
    LED Retrofit Headlamp Light Sources Ensure legal access to the German automotive market Your challenges Before September 2020, the Kraftfahrt-Bundesamt hazards. Other advantages include: (Federal Motor Transport Authority) did not permit the ■ Near-daylight luminescence for improved visibility replacement of vehicle headlamps with LED retrofit ■ Quicker response time to 100% light light sources for driving beams and passing beams in ■ Highly resistant to vibration and shock Germany, as the appropriate homologation guidelines did ■ Longer lifetime not exist. Consequently, vehicle owners could not modify ■ Higher efficiency (lm/W), fewer CO2 emissions and their old halogen lamps with LEDs and manufacturers more environmentally friendly were unable to sell LED retrofits for vehicles registered on German public roads. Why is retrofitted LED headlamp light source testing and compliance important? The advantages of headlamps equipped with All external light sources on a vehicle, such as headlights or LED retrofit brake lights, are considered “technical lighting equipment” According to a study by the Allgemeiner Deutscher and must be type approved. Any subsequent modifications Automobil-Club (ADAC), retrofitting car headlights with to the type-approved lighting equipment will have an impact LEDs offers a road traffic safety gain. This is because on the type approval of the entire vehicle, and result in the retrofitted LED headlights are more durable, have a longer loss of the operating licence for public roads. beam range and their white light improves contrast. It is therefore essential that any LED updates made to Overall, LEDs have been proven to increase driver safety headlamps are installed correctly, do not disadvantage through improved visibility and earlier detection of road other road users and meet current safety requirements.
    [Show full text]
  • Introduction 1
    1 1 Introduction . ex arte calcinati, et illuminato aeri [ . properly calcinated, and illuminated seu solis radiis, seu fl ammae either by sunlight or fl ames, they conceive fulgoribus expositi, lucem inde sine light from themselves without heat; . ] calore concipiunt in sese; . Licetus, 1640 (about the Bologna stone) 1.1 What Is Luminescence? The word luminescence, which comes from the Latin (lumen = light) was fi rst introduced as luminescenz by the physicist and science historian Eilhardt Wiede- mann in 1888, to describe “ all those phenomena of light which are not solely conditioned by the rise in temperature,” as opposed to incandescence. Lumines- cence is often considered as cold light whereas incandescence is hot light. Luminescence is more precisely defi ned as follows: spontaneous emission of radia- tion from an electronically excited species or from a vibrationally excited species not in thermal equilibrium with its environment. 1) The various types of lumines- cence are classifi ed according to the mode of excitation (see Table 1.1 ). Luminescent compounds can be of very different kinds: • Organic compounds : aromatic hydrocarbons (naphthalene, anthracene, phenan- threne, pyrene, perylene, porphyrins, phtalocyanins, etc.) and derivatives, dyes (fl uorescein, rhodamines, coumarins, oxazines), polyenes, diphenylpolyenes, some amino acids (tryptophan, tyrosine, phenylalanine), etc. + 3 + 3 + • Inorganic compounds : uranyl ion (UO 2 ), lanthanide ions (e.g., Eu , Tb ), doped glasses (e.g., with Nd, Mn, Ce, Sn, Cu, Ag), crystals (ZnS, CdS, ZnSe, CdSe, 3 + GaS, GaP, Al 2 O3 /Cr (ruby)), semiconductor nanocrystals (e.g., CdSe), metal clusters, carbon nanotubes and some fullerenes, etc. 1) Braslavsky , S. et al . ( 2007 ) Glossary of terms used in photochemistry , Pure Appl.
    [Show full text]
  • Request to Renew Exemption 1(A)
    Request to renew Exemption 1(a) under the RoHS Directive 2011/65/EU Mercury in single-capped (compact) fluorescent lamps below 30 W Date: January 15, 2015 LIGHTINGEUROPE Contents Contents ................................................................................................................... 2 1 Name and contact details ................................................................................. 4 2 Reason for application ...................................................................................... 4 3 Summary of the exemption request .................................................................. 4 4 Technical description of the exemption request ................................................ 7 4.1 Description of the lamps and their applications .................................................. 7 4.1.1 Lamps covered by this exemption .................................................................. 7 4.1.2 Applications covered by this exemption .......................................................... 8 4.1.3 Annex I category covered by this exemption ................................................ 10 4.2 Description of the substance ............................................................................ 11 4.2.1 Substance covered by this exemption .......................................................... 11 4.2.2 Function of mercury in lamps ....................................................................... 11 4.2.3 Location of mercury in lamps.......................................................................
    [Show full text]
  • Tips for Improved Luminescence Performance Getting the Most of out of Your Biotek Reader
    Tips for Improved Luminescence Performance Getting the Most of Out of Your BioTek Reader In order to achieve the best possible luminescence results from your BioTek microplate reader, several different parameters must be addressed. While there are an infinite number of possible combinations, addressing just a few key issues will greatly increase the likelihood of experimental success. In this technical note, we describe some of those issues and parameters. Introduction BioTek offers two reader series capable of measuring fluorescence: the Synergy HT and the FLx800. Depending on the model and type the end user will be able to perform various luminescent reactions. For example, only those readers configured with injectors have the capability to perform flash luminescence assays, while virtually all the luminescent capable readers can perform glow assays. Listed below are several different parameters, which may or may not apply to any one specific reader. Getting Started Plate Type: The type of plate used does matter. Opaque white plates have been shown to provide the best performance for luminescence assays, as they maximize the signal. Other plates can be used, such as white sided with clear bottom if necessary. Solid black plates will also work, but the signal will be significantly reduced. Quality plates should not allow any light leakage through the walls of the microplate. Filter Wheel Settings: In order to prevent any stray light from entering the optical path, an opaque plug is located in the excitation wheel in lieu of an excitation filter. Generally an open aperture on the emission filter wheel is used when performing luminescence measurements.
    [Show full text]
  • Electroluminescence Vs. Photoluminescence
    Electroluminescence vs. Photoluminescence This application note presents a brief comparison in characterization of light-emitting material such as GaN using electroluminescence and photoluminescence. In photoluminescence (PL), excess carriers (electrons and holes) are photo-excited by exposure to a sufficiently intense light source, and the luminescence emitted from the radiative recombination of these photo-excited carriers. PL mapping combines conventional PL with a scanning stage. Both the intensity and the peak wavelength uniformity across the whole wafer can thus be acquired and used for evaluation. Electroluminescence (EL) is similar to photoluminescence, except that in electroluminescence the excess carriers are produced by current injection and it is usually measured on finished device. The photoluminescence is mainly determined by the optical properties of the material, while the electroluminescence is determined by a number of factors such as the optical properties and physical structures of the optically active layers, the electrical properties of two conductive regions which are used for cathode and anode contacts, and the properties of the electrical contacts through which the electrical current injected. It is well known that photoluminescence is not equivalent to electroluminescence. High photo-luminescence efficiency is necessary but not sufficient for good light-emitting materials or wafers. A wafer with high photoluminescence efficiency may or may not exhibit high electroluminescence efficiency and hence good light emitting diodes (LEDs). The different emission mechanism between PL and EL could also result in huge emission wavelength/intensity change. It has been reported that, at least in green LED, top contact layer could change the MQW PL emissions dramatically, and EL spectra from the fabricated devices were very different from the MQW PL measurements.
    [Show full text]
  • On the Model of a Compact Fluorescent Lamp As Load of a Mixed Lv Network
    Proc. EUROSIM 2007 (B. Zupančič, R. Karba, S. Blažič) 9-13 Sept. 2007, Ljubljana, Slovenia ON THE MODEL OF A COMPACT FLUORESCENT LAMP AS LOAD OF A MIXED LV NETWORK Mihaela Albu1, Aurel–Ionuţ Chirilă1, Ioan–Dragoş Deaconu1 1”Politehnica” University of Bucharest, Faculty of Electrical Engineering, 060042 Bucharest, Splaiul Independenţei 313, Romania [email protected] (Albu Mihaela) Abstract The need of an optimal integration of dispersed generation (mainly based on renewable sources, which are usually intermittent and provide electricity in DC form) led to a new distribution system, which includes DC layer as an active network (generation, storage and loads are all interconnected at direct voltage by means of uni- or bi-directional power electronics converters). At a first stage, these DC networks should operate interconnected with the AC distribution system. One main application in the near future is considered to be the use of a DC layer in office buildings. Therefore, models of the system components have to be developed, as to accurately simulate the network behavior for various states. In this paper, firstly a PSpice model of a CFL lamp was derived, as to allow different simulations conditions when supplied with DC at various voltage levels. Then a set of experiments conducted both in DC and AC enabled the model validation. For various CFLs, the I(U) characteristics were obtained and appropriate numerical model of the corresponding CFL impedance for DC supply were derived, as to be further implemented in complex grid models developed within Matlab workspace. Finally, conclusions regarding the efficiency of a DC supply grid are drawn, together with an assessment within the power quality frame.
    [Show full text]
  • Exploring Photoluminescence
    Name: Class: LUMINESCENCE Visual Quantum Mechanics It’s Cool Light! ACTIVITY 5 Exploring Photoluminescence Goal In the previous activity, we explored several types of luminescence and compared it with incandescence. In this activity, we will investigate luminescent materials that require light to emit light. These materials are called photoluminescent. In a dark room, open the black envelope labeled “A” assigned by your instructor that contains an object that has been placed in it overnight. Take the object out of the envelope. ? Does object “A” emit light? If it does, in the space provided below describe the emitted light. Turn on the lights and expose the object to the light. After a few seconds, turn off the lights. ? Does object “A” seem to emit light when the lights are on? ? Now, turn the light off again. Does light come from object “A” ? If it does, in the space provided below describe the characteristics of the emitted light. Photoluminescence, unlike the other types of luminescence, requires light in order to emit light. As a result, the chart used in the first activity to identify the different types of luminescence (Figure 1-3) needs to be expanded to include Figure 5-1 illustrated on the following page. Kansas State University @2001, Physics Education Research Group, Kansas State University. Visual Quantum Mechanics is supported by the National Science Foundation under grants ESI 945782 and DUE 965288. Opinions expressed are those of the authors and not necessarily of the Foundation. 5-1 Luminescence ENERGY: Light photoluminescence object glows after light is removed yes no phosphorescence fluorescence Figure 5-1: Photoluminescence Addition to Luminescence Chart According to Figure 5-1, a photoluminescent object emits light or glows as a result of shining light on the object.
    [Show full text]
  • LED Laboratory Lighting [PDF]
    Ancient TL Vol. 26 No.1 2008 11 LED laboratory lighting G.W. Berger and C. Kratt Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA (e-mail: [email protected]) (Received 29 April 2008; in final form 21 May 2008) _____________________________________________________________________________________________ Introduction Instrumentation Over the last three decades there have been various We measured optical fluxes (μW/cm2) from our recommendations about laboratory lighting. These various light sources using a NIST-traceable have changed with changing understanding of the calibrated radiometer (Model IL-1400a, International luminescence responses of quartz and feldspars, as Light, www.intl-lighttech.com). Filter F-15957 and a well as with changes in the availability of affordable cosine diffuser are mounted over the UV stabilized lighting technology (e.g., Sutton and Zimmerman, silicon photodiode detector (SEL033). We measured 1978; Jensen and Barbetti, 1979; Spooner and spectra over the range 350-2500 nm, using an Prescott, 1986; Smith, 1988; Galloway and Napier, Analytical Spectral Devices (ASD) Inc. Fieldspec® 1991; Lamothe, 1995; Spooner et al., 2000; Huntley Pro spectroradiometer (www.asdi.com). This and Baril, 2002). spectroradiometer consists of 3 detector arrays (and diffraction gratings), with response boundaries at In reviewing the excitation spectrum of feldspar by ~980 nm and ~1800 nm. The response function has a Ditlefsen (1991) and their own tests on loess, Huntley 10-20% variation over the interval 520-800 nm, and and Baril (2002) summarize that when one is the response falls off by a factor of 4 between ~800 preparing quartz, the reddest visually comfortable nm and 950 nm.
    [Show full text]
  • Worldwide Light Sources and Fluorescent Light Market
    Presentation on Worldwide Light sources and Fluorescent light Presented by: M. M. Ahtashom market Contents • Introduction • Classification of light source • Lighting efficiency comparison • Fluorescent lamp • History background • How light produced • Types of Fluorescent lamp • About Ballast • Operating Charecteristic • Applications • Advantages and Disadvantages • Commercial Prospect • CFL Recycling project • Reference Introduction A typical "light source" emits electromagnetic radiation in the visible spectrum. The list is oriented towards visible light: nearly everything emits photons through blackbody radiation. Classification of Light sources 1. Combustion 2. Natural 2.1 Celestial and atmospheric light 2.2 Terrestrial 3. Direct Chemical 4. Electric Powered 4.1 Electron simulated 4.2 Incandescent lamp 4.3 Electroluminescent (EL) lamp 4.4 Gas discharge lamps 4.4.1 High-intensity discharge lamp 5. Other 1. Combustion •Fire 2. Natural 2.1 Celestial and atmospheric light • Astronomical objects – Sun (Sunlight (solar radiation)) – Starlight (Stars forming groups such as Star clusters and galaxies and indirectly lighting nebulae) • Lightning (Plasma) – Sprite (lightning) – Ball lightning – Upper-atmospheric lightning – Dry lightning • Aurorae • Cherenkov radiation (from cosmic rays hitting atmosphere) • 2.2 Terrestrial • Bioluminescence – Luciferase - found in glowworms, fireflies, and certain bacteria – Aequorea victoria (a type of jellyfish) – Antarctic krill – Parchment worm (Chaetopterus), which exhibits blue bioluminescence despite
    [Show full text]
  • Optical Design of LED-Based Automotive Headlamps
    Optics & Laser Technology 45 (2013) 262–266 Contents lists available at SciVerse ScienceDirect Optics & Laser Technology journal homepage: www.elsevier.com/locate/optlastec Optical design of LED-based automotive headlamps Xiangbing Zhu n, Qian Zhu, Han Wu, Chun Chen Department of Physics, Anhui Normal University, No. 1 Beijing East Road, Wuhu, Anhui 241000, PR China article info abstract Article history: In order to solve the problem of high cost and low optical efficiency of current LED-based headlamps, Received 2 March 2012 we introduced a new optical design approach for LED-based automotive headlamps. In this configura- Received in revised form tion, 48 pieces of LEDs are used to build a LED array and the measuring screen is divided into multiple 27 April 2012 blocks to allow each LED to illuminate a block. A kind of secondary optical lens for a single LED is used Accepted 17 May 2012 so that the lights radiated from a single LED can form a rectangular beam region, whose optical Available online 21 July 2012 efficiency is above 85% in theory. Lighting up different LEDs can illuminate different blocks, so as to Keywords: realize low-beam and high-beam lighting. Ray tracing simulation results fulfill the low-beam and high- Optical design beam optical demands of the regulation. Since low-power LEDs need no additional reflectors, cost lower Light-emitting diodes and obtain higher efficiency than high-power LEDs, this configuration achieves high reliability Headlamp installation and can partially realize the functions of Adaptive Front-Lighting System (AFS). & 2012 Elsevier Ltd. All rights reserved.
    [Show full text]
  • Luminescence Properties of Zno Nanostructures and Their Implementation As White Light Emitting Diodes (Leds)
    Linköping Studies in Science and Technology Dissertation No. 1378 Luminescence Properties of ZnO Nanostructures and Their Implementation as White Light Emitting Diodes (LEDs) Naveed ul Hassan Alvi Physical Electronics and Nanotechnology Division Department of Science and Technology (ITN) Campus Norrköping, Linköping University SE-60174 Norrköping Sweden Linköping 2011 I Copyright © 2011 by Naveed ul Hassan Alvi [email protected] [email protected] ISBN: 978-91-7393-139-7 ISSN 0345-7524 Printed by LiU-Tryck, Linköping University, Linköping, Sweden June, 2011 II III IV Luminescence Properties of ZnO Nanostructures and Their Implementation as White Light Emitting Diodes (LEDs) Naveed ul Hassan Alvi Department of Science and Technology, Linköping University Sweden, 2011 Abstract: In the past decade the global research interest in wide band gap semiconductors has been focused on zinc oxide (ZnO) due to its excellent and unique properties as a semiconductor material. The high electron mobility, high thermal conductivity, good transparency, wide and direct band gap (3.37 eV), large exciton binding energy (60 meV) at room temperature and easiness of growing it in the nanostructure form, has made it suitable for wide range of applications in optoelectronics, piezoelectric devices, transparent and spin electronics, lasing and chemical sensing. In this thesis, luminescence properties of ZnO nanostructures (nanorods, nanotubes, nanowalls and nanoflowers) are investigated by different approaches for possible future application of these nanostructures as white light emitting diodes. ZnO nanostructures were grown by different growth techniques on different p-type substrates. Still it is a challenge for the researchers to produce a stable and reproducible high quality p-type ZnO and this seriously hinders the progress of ZnO homojunction LEDs.
    [Show full text]
  • Power Quality in Modern Lighting: Comparison of LED, Microled and CFL Lamps
    International Conference on Renewable Energies and Power Quality (ICREPQ’16) Madrid (Spain), 4th to 6th May, 2016 exÇxãtuÄx XÇxÜzç tÇw cÉãxÜ dâtÄ|àç ]ÉâÜÇtÄ (RE&PQJ) ISSN 2172-038 X, No.14 May 2016 Power Quality in modern lighting: comparison of LED, microLED and CFL lamps F. G. Montoya1 and J. Castillo1 1 Department of Engineering Area of Electrical Engineering EPS, University of Almeria Crtra. De Sacramento s/n, 04120 La Cañada de San Urbano, Almeria (Spain) Phone/Fax number: +34 950 214501, e-mail: [email protected], [email protected] Abstract. This paper presents a study for the electric their energy saving strategy and energy policy, nations performance of different energy saving lamp types like LED, across the world still promote the use of CFLs type. microLED and Compact Fluorescent Lamp (CFL), under Many researchers around the world focus in reducing nominal operating conditions (sinusoidal waveform of 230 Vrms electrical loading by using efficient energy lighting and 50 Hz) along with abnomal conditions such swells, sags, methods which has resulted in a high-level interest in notch or harmonic distortion in the voltage source. A set of replacing conventional incandescent lamp type with diferent test is also carried out for the selected lamps to Compact Fluorescent Lamps type and LED lamp type [7]. determine the power quality values. Recently, LED lamp types are more widely accepted than Key words CFLs type because of their important advantages in lower power consumption and longer lifetime. Also, LED lamps type, similar to CFLs type, are non-linear in nature and Lighting, Led, CFL, Power Quality, Harmonics hence induce harmonics into the distribution system [7].
    [Show full text]