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In the Bradford protein assay, protein concentrations are determined by the absorbance at 595 nm due to the binding of Coomassie brilliant blue G-250 (CBBG) to proteins. In a protein--CBBG liquid mixture, surface-enhanced Raman scattering (SERS) is sensitive to the amount of unbound CBBG molecules adsorbed on silver surfaces, and the bound CBBG amount is directly related to the target protein concentration. Accordingly, a novel method for detecting total protein concentration in a solution has been developed based on SERS of unbound CBBG with an internal standard of silicon. Two obvious advantages of the proposed protein assay over conventional Bradford protein assay are its much wider linear concentration range ([10.sup.5]-[10.sup.-9] g/mL) and 200 times lower limit of detection ( 1 ng/mL), which demonstrates its great potential in rapid, highly sensitive concentration determination of high and low-abundance proteins. 10.1021/ac100596u

The adsorption of two reactive dyes, Reactive Black 5 and Reactive Red E, onto palm kernel shell-activated carbon (PKSAC) was studied. The effect of the presence of more than one dye in solution on the equilibrium and kinetics of adsorption was investigated. Equilibrium isotherm models were applied to describe the adsorption capacities of single and binary systems. Adsorption of reactive dyes for single system can be represented by the Freundlich and the Redlich-Peterson models. For binary system, the equilibrium was described successfully by the modified extended Freundlich model. Experimental data showed that competitive adsorption for active sites on the carbon surface resulted in a reduction in the overall uptake capacity of the reactive dyes. The rates of adsorption in single system were found to agree well with the pseudosecond-order kinetic model. Finally, the chemical oxygen demand (COD) of the treated reactive dye solutions from single and binary systems showed that a minimum of 4 g/L dosage of PKSAC was needed to reduce the COD to an acceptable level according to the Water Quality Guidelines and the Pollutant Fact Sheets Guidelines. DOI: 10.1061/(ASCE)EE.1943-7870.0000091 CE Database subject headings: Adsorption; Dyes; Chemical oxygen demand; Equilibrium; Activated carbon.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2009.06.004 Byline: Mohammad A. Al-Ghouti (a), Yehya S. Al-Degs (b), Majeda A.M. Khraisheh (c), Mohammad N. Ahmad (d), Stephen J. Allen (d) Abstract: The investigations into structural changes which occur during adsorbent modification and the adsorption mechanisms are essential for an effective design of adsorption systems. Manganese oxides were impregnated onto diatomite to form the type known as [delta]-birnessite. Initial investigations established the effectiveness of manganese oxides-modified diatomite (MOMD) to remove basic and reactive dyes from aqueous solution. The adsorption capacity of MOMD for methylene blue (MB), hydrolysed reactive black (RB) and hydrolysed reactive yellow (RY) was 320, 419, and 204mg/g, respectively. Various analytical techniques were used to characterise the structure and the mechanisms of the dye adsorption process onto MOMD such as Fourier transform infrared (FTIR), X-ray diffraction (XRD) and atomic absorption spectrometry (A.A.). A small shift to higher values of the d-spacing of dye/MOMD was observed indicating that a small amount of the dye molecules were intercalated in the MOMD structure and other molecules were adsorbed on the external surface of MOMD. Two mechanisms of dye adsorption onto MOMD were proposed; intercalation of the dye in the octahedral layers and adsorption of the dye on the MOMD external surface. Moreover, the results demonstrated that the MOMD structure was changed upon insertion of MB and RY with an obvious decrease in the intensity of the second main peak of the MOMD X-ray pattern. Author Affiliation: (a) Royal Scientific Society, Industrial Chemistry Centre, P.O. Box: 1438, Al-Jubaiha 11941, Jordan (b) School of Chemistry, Hashemite University, Zarqa, Jordan (c) Department of Civil and Environmental Engineering, University College London, Chadwick Building, Gower Street, London WC1E 6BT, UK (d) School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK Article History: Received 23 June 2008; Revised 7 May 2009; Accepted 3 June 2009

The solvation characteristic of ketocyanine dye is studied by monitoring the absorption band of the dye in two ternary solvent mixtures. The maximum energy of absorption (E) of the dye, in both ternary and binary solvents mixtures are found to be deviated significantly from the mole fraction average of the E values in the component solvents.

The syntheses and the spectroscopic properties of the 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BPDIPY) dyes and their derivatives are discussed. The analysis shows that the fluorescence characteristics of these compounds can be easily altered by changing their structures.

The fluorescence and photophysical properties of sulfoindocyanine Cy3 dye attached covalently to single-stranded and duplex DNA that could be applied to investigate the structure and dynamics of nucleic acids is presented.

The result from investigation of the regulation on the aggregation and morphology of two cyanine dyes, by using a series of gemini amphiphiles revealed both the dyes ability to be adsorbed onto monolayers of the gemini amphiphiles through the electrostatic and [pi]-[pi] interaction and stacked into H- or J-aggregate.

The synthesis and the photovoltaic properties of a large number of efficient organic dyes, which consist of the benzo[b]furan moiety is studied. The analysis shows that the dyes are prepared by a one-pot coupling cyclization step, which makes it useful for various applications like the fabrication of a nanocrystalline Ti[O.sub.2] dye-sensitized solar cell.

The evaluation of the diradical character of the oxyallayl derivatives by using the density functional theory (DFT) methods with broken symmetry formalism has revealed that it is underestimated. The deviations in both the squaraine series are found to be systematic, whereas croconate dyes have higher deviation even after inclusion of the solvent effects.

The effect of varying acid and dye concentration on the absorption spectra of the bromo and iodo substituted dyes, bis(3,5-dibromo-2,4,6-trihydroxyphenyl)squaraine (SqBr) and bis(3,5-diiodo-2,4,6-trihydroxyphenyl)squaraine (SqI), is investigated. The formation of the J-type dimer aggregates are obtained by comparing the differences in the triplet excited state properties of the neutral and aggregated forms of the dyes by using time-resolved spectroscopy.

The solvent strength of IL/organic mixtures is reported using Reichardt's dyes 30 and 33, Kamlet-Taft parameters and phenol blue. The results shows that the polarity of ILs is largely unaffected by the organic consolvent that is the probes are preferentially solvated by the ILs.

The synthesis and structure of three novel coordination polymers are explored by using hydrothermal methods. The samples are characterized by using a variety of techniques and all the compounds have appeared to be active for the photocatalytic decomposition of common organic dyes used in textile industries.

A new terrylene diimide-based dye (WS-TDI) that is soluble in water was synthesized and its photophysical properties are investigated. A single molecule study of WS-TDI in polymeric films of PVA and PMMA reveals excellent photostability with respect to photobleaching, far above the photostability of other common water-soluble dyes, such as oxazine-1, sulforhodamine-B, and a water-soluble perylenediimide derivative.

Detection of cellular response by measuring intracellular calcium, [([Ca.sup.2+]).sub.i] with [Ca.sup.2+]-dependent fluorescent dye are standard approaches to detect ligand-stimulated cells and to study signaling through ligand/receptor interaction. We describe a single-cell microarray system to analyze cellular response of individual cells such as lymphocytes using microchamber array chips. The single-cell microarray chip is made from polystyrene with over 30 000 microchambers, which can accommodate only single cells. Lymphocytes derived from mouse spleen or human blood were spread on the microarray, and over 80% of the microchambers achieved single-cell status. Stimulation of B-cells through antigen receptors on the microarray allowed us to detect activated B-cells by comparing the states of single B-cells before and after stimulation with antigen, which is disabled for flow cytometry. In addition, this novel method demonstrated retrieval of positive single B-cells from microchambers by a micromanipulator and achieved antibody DNA analysis. The system is suitable for high-throughput analysis of intracellular [Ca.sup.2+] response at the single-cell level and is applicable to screen antigen-specific lymphocytes for making specific monoclonal antibody.

A high level symmetry adapted cluster-configuration interaction (SAC-CI) calculations of some substituted SQ and CR dyes were carried out and the absorption energy was compared with the existing experimental data. The objective of the exercise was to understand the role of the central ring and the substitutions in the absorption of the dyes.

The photophysical properties of an organic dye (Congo Red) incorporated within the internal cavities of a dendrimer (type polypropylenimine of fifth-generation modified with a dense shell of amino acids) is investigated. It is observed that the emission frequencies of Congo Red, on modulation by electronic confinement effect, can be red shifted with respect to their emission solution, and the magnitude of this shifting can be modulated under appropriate experimental conditions.

Abstract -- The efficiency of capillary electrophoresis was demonstrated in determining food dyes in alcoholic beverages. The relative standard deviation was below 10% in the dye concentration range between 5 [...]

Abstract -- Spectrophotometry was used to study the interaction of high-molecular polyacrylamide with cationic dyes: Methylene Blue, Acridine Yellow, and Toluidine Blue. Polyacrylamide samples were modified by alkaline hydrolysis. The [...]

The synthesis of diverse meso-aminophenyl-, hydroxyphenyl-, and phenyl-substituted heptamethine cyanine dyes by using modified Suzuki-Miyaura method is demonstrated. The new complexes have excellent spectral properties and could be applied to label bioactive molecules and nanoparticles.

Note is presented on the standard lab from a second year chemistry course. The lab 'Determining which of the Seven FD&C Food-Approved Dyes are Used in Making Green Skittles', familiarizes students with the operation of the CHEM2000 UV-Vis spectrophorometer.

A suitable combination of a cobalt polypyridine complex and an organic sensitizer is selected for developing dye-sensitized solar cells (DSCs) with cobalt-based mediators with efficiencies surpassing the record for DSCs with iodide-free electrolytes. The optimization of DSCs sensitized with a triphenylamine-based organic dye in combination with tris(2,2E-bipyridyl)cobalt(II/III) has produced solar cells and excellent performance is observed under low light intensity indoor conditions.

Millimeter-sized single MOF-5 crystals are used as chromatographic columns to separate mixtures of organic dyes. The separations have occurred over a distance of only a few hundred micrometers that is confirmed by fluorescence confocal microscopy, which is due to the nanoscopic pore dimensions and the molecular-level interactions between the migrating molecules and the metal-organic framework (MOF) scaffold.

The synthesis, electronic properties and performance in dye-sensitized solar cells (DSSCs) of four cone-shaped organic dyes (ITD, ITD-Th, ITD-Hx, and ITD-OM) containing the isotruxene [pi]-scaffold are reported. The DSSCs fabricated with the cone-shaped organic dyes exhibited high open-circuit voltages and fill factors with a power conversion efficiency ([eta]) up to 5.45%, which is 80% of the ruthenium dye N719-based standard cell fabricated and measured under the same conditions.

X-ray crystallography was used to determine the crystal structure and understand the self-assembly of a DNA crystal that contains two tensegrity triangle molecules per asymmetric unit. The pair of dyes (Cy3 dye (pink) or Cy5 dye (blue-green) was attached to the pair of molecules to demonstrate the control over the colors of the crystals to yield purple crystal.

The syntheses of several derivatives of two new dye systems, with one or two dialkylamino donor groups attached to resonant positions at the periphery of a trioxatriangulenium ion, are described. The optical properties of the new triangulenium dyes and their triphenylmethylium (TPM) precursors are examined and are shown to be dependent on symmetry and charge localization in the conjugated framework.

A method is proposed for measuring the effect of an externally applied electric field on the absorption of dye monolayers adsorbed on flat Ti[O.sub.2] substrates. The result could have significant implications for the analysis of transient absorption spectra of dye-sensitized solar cells (DSCs) and other molecular optoelectronic devices.

A sensor molecule, AS140-MFC, consisting of a covalent adducts of an Ala-to-Cys mutant of [alpha]-synuclein with the 3-hydroxychromone dual emission dye MFC is demonstrated. The AS140-MFC construct which is a multiparametric fluorescent probe could be suitably applied for the continuous monitoring of protein aggregation and is sensitive to the early and intermediate stages of [alpha]-synuclein aggregation, a process associated with ParkinsonEs disease.

A norbornene-tetrazine cycloaddition and a bioorthogonal and modular conjugation method was applied for efficient coupling of organic dyes and biomolecules to quantum dots (QDs). The method could also be applied for the in situ targeting of norbornene-coated QDs to live cancer cells labeled with tetrazine-modified proteins.

The versatile chemistry of Bodipy dyes which facilitates the design and synthesis of multivalent-multitopic derivatives based on the selection of metal ion-ligand pairs to afford photoinduced electron transfer and internal charge transfer processes is reported. The different metal ions with careful design could selectively modulate diverse photophysical processes to result in a range of signals, useful in molecular logic design, and an interesting potential for multianalyte chemosensors.

The rich linear optical properties of (001), (110), and (111) sections of mixed crystals of the propeller-shaped dye molecules by NaCl[O.sub.3], are described. The findings highlighted the possible route to achieve a poor resolution-even an equal population of P and M propellers-within a given chiral NaCl[O.sub.3] crystal and still have a large circular dichroism.