Analytical applications of bioluminescence

The phenomenon of bioluminescence has, since the time of Sir Robert Boyle, attracted the interest of scientific researchers. The detailed mechanisms of many bioluminescent systems are now well understood and have the potential to form the basis of accurate and sensitive analytical methods.     

Analytical applications of peroxyoxalate chemiluminescence

Peroxyoxalate chemiluminescence can be applied to the determination of hydrogen peroxide and aromatic hydrocarbon fluorophores in a static system. Hydrogen peroxide causes a linear response in the range 10^-6–10^-1M when bis(2,4,6-trichlorophenyl) oxalate is used with perylene as the fluorophore. As the intensity of chemiluminescence from different aromatic hydrocarbons varies substantially, there is a degree of selectivity in their determination. If metal chelates are employed as fluorophores, trace metal analysis is possible.     

Analytical studies using iodine-luminol chemiluminescence

Trace amounts of substances have been related to iodine consumption monitored by chemiluminescence from the iodine-luminol system. Iodine titrations of sulphite and arsenic(III) have been carried out at levels of 1.0 x 10(-7) and 5.0 x 10(-8)M with a precision and error of better than 1% on a day-to-day basis. A calibrated standard of 1.8 ppm SO(2) in air was analysed with a precision of +/-1.2%, and an error of 0.9%. A rate method has been developed based on the reaction between iodine and penicillin G; a linear range from 10(-8) to 10(-7)M was found, the precision being +/-9%.     

Analytical applications of nanomaterials in electrogenerated chemiluminescence

This critical review covers the use of carbon nanomaterials (single-wall carbon nanotubes, multi-wall carbon nanotubes, graphene, and carbon quantum dots), semiconductor quantum dots, and composite materials based on the combination of the aforementioned materials, for analytical applications using electrogenerated chemiluminescence. The recent discovery of graphene and related materials, with their optical and electrochemical properties, has made possible new uses of such materials in electrogenerated chemiluminescence for biomedical diagnostic applications. In electrogenerated chemiluminescence, also known as electrochemiluminescence (ECL), electrochemically generated intermediates undergo highly exergonic reactions, producing electronically excited states that emit light. These electron-transfer reactions are sufficiently exergonic to enable the excited states of luminophores, including metal complexes, quantum dots and carbon nanocrystals, to be generated without photoexcitation. In particular, this review focuses on some of the most advanced and recent developments (especially during the last five years, 2010–2014) related to the use of these novel materials and their composites, with particular emphasis on their use in medical diagnostics as ECL immunosensors.     

Functional nanocomposites for energy storage: chemistry and new horizons

Energy storage devices are one of the hot spots in recent years due to the environmental problems caused by the large consumption of unsustainable energy such as petroleum or coal. Capacitors are a common device for energy storage, especially electrical energy. A variety of types including electrolytic capacitors, mica capacitors, paper capacitors, ceramic capacitors, film capacitors, and non-polarized capacitors have been proposed. Their specific applications depend on their intrinsic properties. Dielectric capacitors have reasonable energy storage density, with current research focusing on the enhancement of energy density and making the materials more flexible as well as lightweight. Improvement strategies are based on the premise that use of two or more different materials (e.g. polymers and ceramics/metals) at an optimal formulation can result in properties that combine the advantages of the precursor materials. Different polymers especially fluoropolymers (e.g. PVDF and PVDF based co-polymer) are the main components in dielectric nanocomposites for capacitors with high energy storage performance. In this article, we have briefly summarized the recent advances in functional polymers nanocomposites for energy storage applications with a primary focus on polymers, surface engineering, functional groups and novel synthesis/manufacturing concepts applied to new materials. The article presents a unique integrated structure and approaches providing key knowledge for the design and development of novel, low-cost, multifunctional next-generation energy storage materials with improved efficiency.     

Poly(vinyl chloride) and other chlorine containing polymers: the latest achievements in the investigations

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Poly(vinyl chloride) and other chlorine containing polymers: the latest achievements in the investigations     

Electrochemistry of graphene: new horizons for sensing and energy storage

Graphene is a new 2D nanomaterial with outstanding material, physical, chemical, and electrochemical properties. In this review, we first discuss the methods of preparing graphene sheets and their chemistry. Following that, the fundamental reasons governing the electrochemistry of graphene are meaningfully described. Graphene is an excellent electrode material with the advantages of conductivity and electrochemistry of sp² carbon but without the disadvantages related to carbon nanotubes, such as residual metallic impurities. We highlight important applications of graphene and graphene nanoplatelets for sensing, biosensing, and energy storage. © 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 211–223; 2009: Published online in Wiley InterScience ( www.interscience.wiley.com ) DOI 10.1002/tcr.200900008     

Analytical applications of photoinduced chemiluminescence in flow systems--a review

In this review, the recent evolution and the state of the art of photochemical reactions coupled with chemiluminescence processes are presented. Different chemiluminescence systems have been considered together with suitable photochemical derivatization processes that can affect either the analyte of interest or even the chemiluminogenic reagent, producing some derivatives able to participate more efficiently in the CL reactions and enhancing the CL emission. The on-line integration of the photochemical reactions as well as the coupling of this resulting photoinduced chemiluminescence (PICL) method with dynamic analytical systems, such as flow injection analysis, liquid or gas chromatography and capillary electrophoresis, have been discussed. Important applications of PICL have been proposed in environmental, pharmaceutical and food analysis.     

Analytical and spectral features of gas-phase chemiluminescence spectrometry of arsenic and antimony

Intense emissions are produced in the u.v. and visible regions when arsine and stibine are introduced into a flow-type furnace—hydrogen diffusion flame system, when the flame is surrounded by oxygen. The emissions in the range 240–300 nm are attributed to AsO and SbO. The emission characteristics seem to be due to chemiluminescence based on the reaction between atomic analyte and oxygen. The detection limits are 0.05 μAs (10 ppb) at 429 nm and 0.1 μ Sb (20 ppb) at 369 nm.     

Zeolite-supported tetramethyl-1,2-dioxetane: new pathways to chemiluminescence

The thermal decomposition of tetramethyl-1,2-dioxetane (TMD) sorbed into zeolite Y containing Eu³⁺ ions and 2,2'-bipyridine (samples abbreviated as ZYEBT) has been investigated. Decomposition of TMD yields, by energy transfer processes, chemiluminescence (CL) characteristic of the Eu³⁺ ion. At loading levels corresponding to an upper-limit average of 0.5, 1.0, and 2.0 TMD molecules per unit cell, the CL decay curves are nonexponential at short times; at longer times,roughly exponential curves are characterized by a unimolecular rate constant k. Analyses of the longtime decays based on an Arrhenius expression for the rate constant provide evidence for a kinetic compensation effect : plots of log k vs. the activation energy E_a as a function of TMD loading level are linear. Solution data (benzene, benzonitrile) fall on the same line, suggesting that TMD decomposes by a common rate-limiting mechanism in these various environments. The Arrhenius parameters (E_a and the pre-exponential factor A) are smaller than the solution values and increase with TMD loading. When TMD is sorbed to the extent of an upper-limit average of ~7 molecules per unit cell, CL decay curves are initially nearly flat and then show an increase in decomposition rate with time. Mechanistic implications of these results are discussed.     

Back electron transfer in electron-exchange chemiluminescence of oxyaryl-substituted spiroadamantyl dioxetane, an analog of firefly bioluminescence

The viscosity dependence of the excitation yield of the singlet oxybenzoate anion, an emitter of electron-exchange chemiluminescence of oxyaryl-substituted spiroadamantyl dioxetane, a chemical analog of firefly bioluminescence, was studied. At 299, K the excitation yield increases from 8 to 23% as the content of diphenylmethane in its mixture with benzene increases to 97%. This effect was quantitatively interpreted in terms of a probabilistic model of the solvent-cage effect, assuming that the chemiexcitation results from the back electron transfer between the products of chemically initiated decomposition of the starting reagent. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 655–661, April, 2000.     

Analytical assessment of the oscillating chemical reactions by use chemiluminescence detection

This paper introduces the chemiluminescence (CL) detection in oscillating reaction-based determinations using the analyte pulse perturbation technique, a straightforward and expeditious approach to deriving quantitative analytical information from oscillating chemical reactions. The behavior of the H(2)O(2)-KSCN-CuSO(4)-NaOH oscillating system in the presence of luminol was examined by using the proposed detection method and the classical potentiometric technique. Some analytical and practical aspects of both detection systems are discussed. A new analytical method for the determination of vitamin B(6) based on the sequential perturbation produced by different amounts of this substance on the oscillating chemical system was also developed in order to assess the potential of CL detection for routine analyses. The calibration curve thus obtained was linear over the range 0.5-2.0 mumol of vitamin B(6), and the precision and throughput were also quite good (3.04% as RSD and nine samples h(-1), respectively). The proposed method was validated by determining the vitamin in pharmaceutical preparations.     

Cypridina bioluminescence—VII : The bioluminescence of Cypridina luciferin analogs

The relative rates of bioluminescence, as well as chemiluminescence, among Cypridina luciferin analogs, and the relative light yield between bioluminescence and chemiluminescence of each of the analogs have been measured with reference to Cypridina luciferin.     

A new chemiluminescence system for determination of cobalt

The chemiluminescence of the reaction of tartaric acid with hydrogen peroxide in the presence of Co(II) in alkaline buffer media has been examined. The maximum emission wavelength is 460 nm. The kinetic curve of the chemiluminescence system has been modelled with a computer, and the reaction conditions have been optimized. Foreign ions, such as Fe(II), Cr(III) and Mn(II), interfere when present in more than 10-fold ratio to Co(II), but several ions can be tolerated when present in higher ratios to Co(II). The concentration range of linear response is from 3.5 x 10(-9) to 2.0 x 10(-6) g/ml, and the detection limit is 4 x 10(-11) g/ml. The procedure has been satisfactorily applied to determine trace cobalt in human blood serum.     

Red light in chemiluminescence and yellow-green light in bioluminescence: color-tuning mechanism of firefly, Photinus pyralis, studied by the symmetry-adapted cluster-configuration interaction method

The yellow-green luminescence from firefly luciferase has long been understood to be the emission from enol-oxyluciferin. However, a recent experiment showed that an oxyluciferin constrained to the keto form produced a yellow-green emission in luciferase (Branchini, B. R.; Murtiashaw, M. H.; Magyar, R. A.; Portier, N. C.; Ruggiero, M. C.; Stroh, J. G. J. Am. Chem. Soc. 2002, 124, 2112-2113). The present quantum mechanical/molecular mechanical and symmetry-adapted cluster-configuration interaction (SAC-CI) theoretical study supports the keto-form to be the yellow-green bioluminescence state in luciferase. We give the theoretically optimized structure of the excited state of oxyluciferin within luciferase, which gives luminescence calculated by the SAC-CI method that is close to the experimental value. Coulombic interactions with neighboring residues, in particular Arg218 and the phosphate group of AMP, play important roles in the color-tuning mechanism. Transformation to the enol form is energetically unfavorable in the luciferase environment. The twisted intramolecular charge-transfer (TICT) state is meta stable and would be easily relaxed to the co-planer structure. Further analyses were performed to verify the spectral-tuning mechanism based on the protonation state and the resonance structure of oxyluciferin.