Dichromated Gelatin with High Sensitivity in the Visible Region

1990 ◽  
Author(s):  
Margarita Mazakova ◽  
Marga Pantcheva ◽  
Georgi Spassov ◽  
Peter Sharlandjiev
Keyword(s):  
Visible Region ◽  
High Sensitivity ◽  
Dichromated Gelatin

scholarly journals A new method for the selective isolation of cysteine-containing peptides. Specific labelling of the thiol group with a hydrophobic chromophore

1983 ◽  
Vol 211 (1) ◽  
pp. 163-171 ◽  
Author(s):  
J Y Chang ◽  
R Knecht ◽  
D G Braun
Keyword(s):  
High Pressure ◽  
Light Chain ◽  
Visible Region ◽  
High Sensitivity ◽  
Thiol Group ◽  
Reversed Phase ◽  
New Method ◽  
Kappa Light Chain ◽  
Selective Isolation ◽  
Specific Labelling

A new method for the selective isolation of cysteine-containing peptides was designed. The method is based on the specific labelling of thiol groups with a hydrophobic chromophore followed by enzymic fragmentation of the labelled protein and reversed-phase high-pressure liquid-chromatographic separation of the peptide mixture. This new method has several distinct advantages: (1) the hydrophobic-chromophore-labelled cysteine-containing peptides are easily separated from non-cysteine-containing peptides by reversed-phase high-pressure liquid chromatography; (2) only cysteine-containing peptides are detected in the visible region with sensitivity at the low picomole level; this high sensitivity allows isolation of nanogram amounts of pure cysteine-containing peptide; (3) during sequence determination of the chromophore-labelled cysteine-containing peptides, the cysteine residues are released as coloured anilinothiazolinone derivatives and can be detected directly in the picomole range; (4) with proteins bearing several disulphide groups, each disulphide group may undergo a different degree of reduction, and therefore the recovery of individual cysteine-containing peptides may be used to deduce the disulphide linkages present in the native protein. Two thiol-specific reagents, 4-dimethylaminoazobenzene-4′-iodoacetamide and 4-dimethylaminoazobenzene-4′-N-maleimide, were synthesized and characterized. The method was successfully used to isolate five cysteine-containing peptides from a completely reduced monoclonal-antibody kappa-light chain raised against the azobenzenearsonate determinant and six cysteine-containing peptides from a kappa-light chain raised against streptococcal group A polysaccharide. The principle of this method is applicable to the isolation of any peptide containing amino acid residues that can be specifically labelled with a hydrophobic chromophore.

Interface between Nanophotonics and Biotechnology: How the Near-Field Can Boost Proteomics Based on LSPR Nano Sensor

2010 ◽  
Vol 139-141 ◽  
pp. 1554-1557 ◽  
Author(s):  
Xi Xi Huang ◽  
Zhong Cao ◽  
Yong Le Liu ◽  
Yi Min Dai ◽  
Ju Lan Zeng ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Low Cost ◽  
Near Field ◽  
Visible Region ◽  
High Sensitivity ◽  
Nano Particles ◽  
Localized Surface Plasmon ◽  
Bioanalytical Application

An novel optical nano biosensor based on gold capped nano-particles for detecting binding events between ligands and receptor molecules as well as interactions among proteins without use of labels has been presented in this paper. The optical properties of nano-sized gold particles exhibiting pronounced adsorption in the visible region which called as localized surface plasmon resonance (LSPR) have been exploited, whose peak wavelengths depended exquisitely on the refractive index of the surrounding. In comparison with surface plasmon resonance (SPR) technology, the optical nano biosensor possessed high sensitivity, surprisingly low “bulk effect”, ease of preparation, and low-cost polymer based fabrication, which opened a promising bioanalytical application in practice.

Synthesis and Characterization of Mixed-Halide Inorganic-Organic Hybrid CH3NH3PbBr2.5Cl0.5 Perovskite for Photodetector Application

2021 ◽  
Vol 16 (5) ◽  
pp. 707-714
Author(s):  
Yan Chen ◽  
Siwen Tao ◽  
Yaqi Liu ◽  
Xuewei Fu ◽  
Mengyi Pei ◽  
...  
Keyword(s):  
Light Intensity ◽  
Visible Light ◽  
Single Crystal ◽  
Bias Voltage ◽  
Metal Ion ◽  
Low Cost ◽  
Visible Region ◽  
High Sensitivity ◽  
Photocurrent Density ◽  
Organic Hybrid

Inorganic-organic hybrid perovskite (ABX3, A = organic cation, B = metal ion, X = halogen anion) combines the advantages of inorganic and organic materials. However, the properties and performance of mixed-halide CH3NH3PbBr2.5Cl0.5 (MAPbBr2.5Cl0.5) are still poorly understood. In this study, we synthetized MAPbBr2.5Cl0.5 single crystal and studied its structure, optical, thermal stability properties and optoelectronics applications for photodetector device. Compared with those of MAPbCl3, the interplanar distance of (100) crystal plane for MAPbBr2.5Cl0.5 becomes larger and the absorption spectrum of MAPbBr2.5Cl0.5 is extended to the visible region. The band gap of the MAPbBr2.5Cl0.5 single crystal is 2.28 eV. We find the device based on MAPbBr2.5Cl0.5 has high selectivity from 369 to 564 nm. The maximum ▴J (Jon– Joff) under 3.0 V bias voltage is about 1.2 µAcmr-2 at 454 nm visible light with 1 W mr-2 light intensity (1/1000 of the standard sunlight intensity), which proves the device has a high sensitivity. The linear relationship is established between the value of ▴J and light intensity and bias voltage. The fast current intensity transients (Fit) shows that the disappearance period of photocurrent density is 0.3 ms, which indicates the device is rapidly responsive photodetector. The highest value (1.7%) of external quantum efficiency (EQE) and the highest value of detectivities (D) both appear at 480 nm visible light at 4.0 V bias voltage when the irradiation power is 30 W m-2. Therefore, this simple and low-cost photoresponsive device is promising for industrial production of photodetector and photocatalysts device in the future.

Effect of Interface-Related Deep Levels on high Sensitivity of Schottky Diode Photodetector Based on Ultrathin InGaAs Film on Si

1998 ◽  
Vol 533 ◽  
Author(s):  
A. V. Kvit ◽  
M. V. Yakimov ◽  
P. L. Konstantinov ◽  
M. N. Naidenkov
Keyword(s):  
Activation Energy ◽  
Fermi Level ◽  
Quantum Efficiency ◽  
Electric Fields ◽  
Visible Region ◽  
High Sensitivity ◽  
Deep Levels ◽  
Photoluminescence Intensity ◽  
High Quantum Efficiency ◽  
Small Width

AbstractRecently, the Fermi level has been demonstrated to be pinned in GaAs semiinsulating ultrathin (<100 A) films grown at low temperatures [1]. This allows one to construct a detector with “internal” photocurrent amplification. The amplification effect compensates losses in sensitivity due to the small width of light-sensitive layer which absorbs 10 — 50 % of incident radiation. We fabricate photodetector structures with external quantum efficiency more than 1 for visible region. Photogenerated carriers in the GaAs layer are effectively separated by the built-in electric fields formed by the Schottky barrier and by the charge at the GaAs/Si interface. In this work, we show the relationships between spectral sensitivity of the metal-InGaAs/Si structures and In content. We observed the red shift in the photocurrent spectra with increasing In concentration, although photosensitivity of such structures dropped drastically. This shift demonstrates that the thin InGaAs film is actually responsible for photosensitivity. Despite the low photoluminescence intensity, the lowtemperature PL spectra indicate that band gap decreases with indium flux rising during MEE growth. The surprise was that the decrease of the film thickness caused the increase of photosensitivity. The GaAs(20 A)-InGaAs (20 A)/Si structure was the most sensitive one. We also observed high quantum efficiency in near-UV region (up to 0.8). We determined activation energy of elctron and hole traps and their concentration profiles by DLTS. The centers localized on interface between polar and nonpolar semiconductors are responsible for Fermi-level pinning in III-V semiinsulating materials and act as an electron trap with activation energy 0.59 eV. The origin of deep levels is discussed.

Dichromated gelatin for volume holographic recording with high sensitivity. Part I

1982 ◽  
Vol 14 (4) ◽  
pp. 311-315 ◽  
Author(s):  
M. Mazakova ◽  
M. Pancheva ◽  
P. Kandilarov ◽  
P. Sharlandjiev
Keyword(s):  
High Sensitivity ◽  
Holographic Recording ◽  
Dichromated Gelatin

scholarly journals Construction of Rutile-TiO2 Nanoarray Homojuction for Non-Contact Sensing of TATP under Natural Light

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 409 ◽  
Author(s):  
Yan Tang ◽  
Yuxiang Zhang ◽  
Guanshun Xie ◽  
Youxiong Zheng ◽  
Jianwei Yu ◽  
...  
Keyword(s):  
Field Intensity ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Active Sites ◽  
Raw Materials ◽  
Visible Region ◽  
High Sensitivity ◽  
Natural Light ◽  
Broad Absorption Band ◽  
Contact Sensing

Triacetone triperoxide (TATP) is a new terrorist explosive, and most nitrogen-based sensors fail to detect TATP. Herein, a sea urchin-like TiO2-covered TiO2 nanoarray is constructed as a TATP-sensitive homojunction (HJ) by one step hydrothermal method. By taking fluorine-doped tin oxide (FTO) and indium tin oxide (ITO) conducting glass as the substrate, the conducting glass is horizontally and vertically put in the reactor to epitaxially grow TiO2–FTO, TiO2–ITO, TiO2–FTO–HJ and TiO2–ITO–HJ. TiO2–FTO–HJ shows a broad absorption band edge in the visible region and high sensitivity to TATP under the simulating natural light compared with TiO2–FTO, TiO2–ITO, and TiO2–ITO–HJ. E-field intensity distribution simulation reveals that constructing homojunctions between the urchin-shaped TiO2 nanosphere and TiO2 nanoarrays can enhance the localized electromagnetic field intensity at the interface of junctions, which may provide photocatalysis active sites to reduce TATP molecules by promoting charge separation. Moreover, the TiO2–FTO–HJ shows high selectivity to TATP among ammonium nitrate, urea and sulfur, which are common homemade explosive raw materials.

scholarly journals Gate Dependent Tunable Photosensitivity of Copper Phthalocyanine Based Organic Field Effect Transistors

2019 ◽  
Vol 8 (10) ◽  
pp. 4687-4694
Keyword(s):  
Field Effect ◽  
Copper Phthalocyanine ◽  
Field Effect Transistors ◽  
Monochromatic Light ◽  
Visible Region ◽  
High Sensitivity ◽  
Low Noise ◽  
Electromagnetic Spectrum ◽  
Light Illumination ◽  
Weak Light

Organic field effect transistor (OFET) based photodetector with high sensitivity was fabricated using copper phthalocyanine (CuPc) as photoactive channel for weak light detection. The device fabrication was conducted at room temperature using thermal evaporation technique. The opto-electrical properties of the devices under dark and light conditions are studied in this work. The performance of the photodetector depends on the incident wavelength and the intensity of the incident monochromatic light. We also show that the photoresponse could be tuned by the gate bias, which offers an additional benefit for practical applications. The transfer characteristics of the devices appear to enhance under light illumination. A slight enhancement in the carrier mobility was also detected upon illumination. Similarly, the subthreshold swing has been reduced from 1.31 ± 0.18 V/decade under dark condition to 0.76 ± 0.12 V/decade under illumination. Further impact of gate voltage on responsivity, on/off ratio and detectivity was also studied for the proposed device. The maximum photosensitivity and responsivity obtained from these OFET based photodetectors was 237.21 ± 8.02 and 7.77 ± 0.17 A/W respectively at a power density of 1 mW/cm2 while operating at an input voltage of 4 V and bias voltage of -5 V. Also, a maximum detectivity of 1.38 ± 0.03×10 12 Jones was obtained under the same operating condition. The high sensitivity, good stability, low noise and fast response towards weak light with different wavelength imply that OFET based photodetectors are particularly suitable for photodetection in the visible region of electromagnetic spectrum.

scholarly journals Highly Sensitive Gas Sensing Material for Environmentally Toxic Gases Based on Janus NbSeTe Monolayer

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2554
Author(s):  
Deobrat Singh ◽  
Rajeev Ahuja
Keyword(s):  
Charge Transfer ◽  
Transport Properties ◽  
High Performance ◽  
Gas Sensing ◽  
Visible Region ◽  
High Sensitivity ◽  
Binding Strength ◽  
Toxic Gases ◽  
Gas Molecules ◽  
So2 Gas

Recently, a new family of the Janus NbSeTe monolayer has exciting development prospects for two-dimensional (2D) asymmetric layered materials that demonstrate outstanding properties for high-performance nanoelectronics and optoelectronics applications. Motivated by the fascinating properties of the Janus monolayer, we have studied the gas sensing properties of the Janus NbSeTe monolayer for CO, CO2, NO, NO2, H2S, and SO2 gas molecules using first-principles calculations that will have eminent application in the field of personal security, protection of the environment, and various other industries. We have calculated the adsorption energies and sensing height from the Janus NbSeTe monolayer surface to the gas molecules to detect the binding strength for these considered toxic gases. In addition, considerable charge transfer between Janus monolayer and gas molecules were calculated to confirm the detection of toxic gases. Due to the presence of asymmetric structures of the Janus NbSeTe monolayer, the projected density of states, charge transfer, binding strength, and transport properties displayed distinct behavior when these toxic gases absorbed at Se- and Te-sites of the Janus monolayer. Based on the ultra-low recovery time in the order of μs for NO and NO2 and ps for CO, CO2, H2S, and SO2 gas molecules in the visible region at room temperature suggest that the Janus monolayer as a better candidate for reusable sensors for gas sensing materials. From the transport properties, it can be observed that there is a significant variation of I−V characteristics and sensitivity of the Janus NbSeTe monolayer before and after adsorbing gas molecules demonstrates the feasibility of NbSeTe material that makes it an ideal material for a high-sensitivity gas sensor.

scholarly journals Serum Autofluorescence and Biochemical Markers in Athlete’s Response to Strength Effort in Normobaric Hypoxia: A Preliminary Study

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Zofia Drzazga ◽  
Izabela Schisler ◽  
Stanisław Poprzęcki ◽  
Anna Michnik ◽  
Miłosz Czuba
Keyword(s):  
Fluorescence Spectroscopy ◽  
High Altitude ◽  
Fluorescence Intensity ◽  
Metabolic Regulation ◽  
Visible Region ◽  
High Sensitivity ◽  
Biochemical Assay ◽  
Human Organism ◽  
Individual Response ◽  
Altitude Training

The human organism has the ability to adapt to hypoxia conditions. Training in hypoxia is used in sport to improve the efficiency of athletes; however, type of training affects the direction and scope of this process. Therefore, in this study, the usefulness of serum fluorescence spectroscopy to study the assessment of athlete’s response to strength effort in hypoxia is considered in comparison with biochemical assay. Six resistance-trained male subjects took part in a research experiment. They performed barbell squats in simulated normobaric hypoxic conditions with deficiency of oxygen 11.3%, 13% 14.3% compared to 21% in normoxic conditions. Fluorescence intensity of tyrosine revealed high sensitivity on strength effort whereas tryptophan was more dependent on high altitude. Changes in emission in the visible region are associated with altering cell metabolism dependent on high altitude as well as strength training and endurance training. Significant changes in serum fluorescence intensity with relatively weak modifications in biochemical assay at 3000 m above sea level (ASL) were observed. Training at 5000 m ASL caused changes in fluorescence parameters towards the normobaric specific values, and pronounced decreases of lactate level and kinase creatine activity were observed. Such modifications of fluorescence and biochemical assay indicate increased adaptation of the organism to effort in oxygen-deficient conditions at 5000 m ASL, unlike 3000 m ASL. Fluorescence spectroscopy study of serum accompanied by biochemical assay can contribute to the understanding of metabolic regulation and the physiological response to hypoxia. The results of serum autofluorescence during various concepts of altitude training may be a useful method to analyze individual response to acute and chronic hypoxia. An endogenous tryptophan could be exploited as intrinsic biomarker in autofluorescence studies. However, these issues require further research.

scholarly journals Detection of Bio-Relevant Metal Ions by Luminescent Ru(II)-Polypyridyl Based Sensors

2021 ◽  
Author(s):  
Pramod Kumar ◽  
Sushil Kumar
Keyword(s):  
Metal Ions ◽  
Photophysical Properties ◽  
Stokes Shift ◽  
Enzymatic Catalysis ◽  
Visible Region ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Dna And Rna ◽  
Physiological Processes ◽  
Living Organisms

Biorelevant metal ions such as Cu2+ and Fe2+/Fe3+ participate in various biological events which include electron transfer reactions, delivery and uptake of oxygen, DNA and RNA syntheses, and enzymatic catalysis to maintain fundamental physiological processes in living organisms. So far, several analytical techniques have been investigated for their precise detection; however, luminescence-based sensing is often superior due to its high sensitivity, selectivity, fast and easy operation and convenient cellular imaging. Owing to their immense photophysical and photochemical properties stemming from large Stokes shift, absorption in visible region, good photostability and long excited state lifetimes, Ru(II)-polypyridyl-based complexes have gained increasing interest as luminophores. Over past few decades, several Ru(II)-polypyridyl based chemosensors have rapidly been developed for detection of different biorelevant and other metal ions. The main object of this book chapter is to cover a majority of Ru(II)-polypyridyl based chemosensors showing a selective and sensitive detection of bio-relevant Cu2+ and Fe2+/Fe3+ ions. The photophysical properties of Ru(II) complexes, detection of metal ions, sensing mechanism and applications of these sensors are discussed at a length.

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