Modulation of Developmental Transitions by Trehalose-6-phosphate Signaling in Arabidopsis thaliana

This work throw light upon the role of trehalose-6-phosphate(T6P), a proxy for sugar or energy status in plants, in regulating the developmental transitions in Arabidopsis thaliana. The results described in this thesis demonstrate that T6P pathway is necessary for the induction of FLOWERING LOCUS T (FT) in the leaves even under long day conditions. In addition, T6P pathway regulate the expression of micro-RNA 156 (miR156) and the downstream targets independent of FT. Moreover the results in chapter 2 indicate the role of T6P as the age-dependent signal that regulate the expression of miR156 and modulate vegetative phase transition in Arabidopsis thaliana

Trehalose-6-Phosphate: Connecting Plant Metabolism and Development

Beyond their metabolic roles, sugars can also act as messengers in signal transduction. Trehalose, a sugar found in many species of plants and animals, is a non-reducing disaccharide composed of two glucose moieties. Its synthesis in plants is a two-step process, involving the production of trehalose-6-phosphate (T6P) catalyzed by trehalose-6-phosphate synthase (TPS) and its consecutive dephosphorylation to trehalose, catalyzed by trehalose-6-phosphate phosphatase (TPP). T6P has recently emerged as an important signaling metabolite, regulating carbon assimilation and sugar status in plants. In addition, T6P has also been demonstrated to play an essential role in plant development. This review recapitulates the recent advances we have made in understanding the role of T6P in coordinating diverse metabolic and developmental processes

A study on the bacteriological profile of urinary tract infection in adults and their antibiotic sensitivity pattern in a tertiary care hospital in central Kerala, India

Background: Urinary tract infection is one of the most common bacterial infections in humans and a major cause of morbidity. The etiology of UTI and the antibiotic sensitivity pattern varies with the widespread availability of antimicrobial agents; UTI has become difficult to treat because of appearance of pathogens with increasing resistance to antimicrobial agents.Methods: A descriptive study done during January-June 2013. All positive urine culture and sensitivity reports of males and females aged 20-70years were included. A total of 373 positive urine culture cases were taken from the culture and sensitivity register from Microbiology department and details were entered using a questionnaire.Results: Out of 373 adults, males were 137 (36.7%) and females were 236 (63.3%). E. coli (74.3 %) was the most common organism, followed by Klebsiella (15.8%), Enterococcus, Pseudomonas and Staphylococcus. The incidence of UTI was more in patients in the age group of 60-70years. E. coli and Klebsiella were sensitive to Amikacin (97.1%), Nitrofurantoin (90.7%), Gentamycin and Imipenem. Both organisms were resistant to Ampicillin (>90%).Conclusions: In this study, females were mostly affected and the most common organisms were E.Coli and Klebsiella. These organisms were most sensitive to Amikacin, Nitrofurantoin and resistant predominantly to Ampicillin. The sensitivity and resistance pattern of uropathogens to common antimicrobial agents must be taken into account when selecting treatment plans for UTI

Formulation and evaluation of osmotic drug delivery system of ibuprofen

The authors are thankful to Mr.S.Sriram Ashok B.E, Correspondent, Sankaralingam Bhuvaneswari College of Pharmacy, Anaikuttam, Sivakasi, for providing necessary facilities to carry out the work.Aim: The present work was aimed to formulate and evaluate osmotic pump delivery system of Ibuprofen to provide a uniform concentration of drug at the absorption site and thereby maintain the plasma concentration within therapeutic range, which minimizes side effects and reduces the frequency of administration. Material and Methods: In the present work, 5 formulations (F1 to F5)of Ibuprofen osmotic drug delivery systems(ODDS) were prepared using two osmogens (NaCl and KCL) in two concentrations and a control F6 (without osmogens) by wet granulation technique. The excipients used in this study did not alter physicochemical properties of the drug, as tested by FTIR. Prior to compression, the prepared granules were evaluated for flow and compression characteristics. After compression, the tablets were evaluated for hardness, thickness, weight variation, friability, percentage of weight gain, drug content, in vitro release and stability studies. Results: The results revealed that the pre-compression and post-compression parameters are within the limits. Among all the formulations, F3 showed a controlled drug release of 63.54% at the end of 10th hour. The results of optimized formulation (F3) subjected to stability studies for 60 days at 27º±2ºC/60 ± 5% RH and 50º±2ºC/75 ± 5% RH showed that there was no significant change in the drug content and percentage drug release and the product was stable even after 2 months. Conclusions: From the study, it was concluded that Ibuprofen osmotic pump tablet prepared with potassium chloride (10%) as osmogent and cellulose acetate as coating polymer may be considered as a suitable alternative to currently available formulations of Ibuprofen.Objetivos: El objetivo del presente trabajo ha sido formular y evaluar el sistema de suministro de ibuprofeno mediante bomba osmótica para proporcionar una concentración uniforme de fármaco en el sitio de absorción y por lo tanto mantener la concentración plasmática dentro del intervalo terapéutico, lo que minimiza los efectos secundarios y reduce la frecuencia de administración. Material y Métodos: En el presente trabajo, 5 formulaciones (F1 a F5) de sistemas de administración de ibuprofeno osmótico (odds) se prepararon utilizando dos osmoagentes (NaCl y KCl) en dos concentraciones y un control (F6) (sin osmoagentes) por la técnica de granulación en húmedo. Los excipientes utilizados en este estudio no alteran las propiedades fisicoquímicas del fármaco, según lo testado por FTIR. Antes de la compresión, los gránulos preparados se evaluaron para la fluidez y la compresión. Después de la compresión, los comprimidos se evaluaron para la dureza, espesor, variación de peso, la friabilidad, el porcentaje de ganancia de peso, contenido de fármaco, la liberación in vitro y estudios de estabilidad. Resultados: Los resultados revelaron que los parámetros pre y post-compresión están dentro de los límites. Entre todas las formulaciones, F3 mostró una liberación controlada de fármacos de 63,54% al final de la décima hora. Los resultados de formulación optimizada (F3) sometido a estudios de estabilidad durante 60 días a 27º ± 2 °C/60 ± 5% HR y 50±2 °C/75 ± 5% HR mostraron que no hubo ningún cambio significativo en el contenido de fármaco y el porcentaje de liberación del fármaco y el producto fue estable incluso después de 2 meses. Conclusiones: En el estudio, se llegó a la conclusión de que la tableta de bomba osmótica ibuprofeno preparado con cloruro de potasio (10%) como osmoagente y acetato de celulosa como el polímero de revestimiento puede ser considerado como una alternativa adecuada actualmente disponibles para la formulaciones de ibuprofeno.Fund granted by College management and the research work was approved for the award of Degree of Master of pharmacy by The Tamilnadu Dr.MGR Medical University, Chennai, Indi

Impediments to women accountants' career progression in Malaysia / Zubaidah Zainal Abidin, Frances Penafort Ponnu and Marzlin Marzuki

This study examines women in the accounting profession, their perceptions of their own career barriers in their organization, and identifies possible reasons why they leave their organizations and ways to retain them. Seven measurable constructs were established: exclusionary environment;family responsibility; workplace benefit; job jlexibility; corporate policies; job stress; and job demand. A multiple regression analysis is used to explain the effects ofwomen accountant s perception of impediments on career progression. Except for elements ofjob stress, where they appear significant in isolation with career progression, most of the findings disclosed no correlations with career advancement ofwomen accountant. Incidentally, marital status is significantly positively related to career progression. The reasons for leaving the organization indicated by the women accountants' are job demand, work family policy, gender discrimination and etc. Work-family policies such as child care and flexi-time are the most consistent benefits quotedby respondents that will enhance retention of employees

Optical chemosensors and reagents to detect explosives

[EN] This critical review is focused on examples reported from 1947 to 2010 related to the design of chromo-fluorogenic chemosensors and reagents for explosives (141 references). © 2012 The Royal Society of Chemistry.Financial support from the Spanish Government (project MAT2009-14564-C04) and the Generalitat Valencia (project PROMETEO/2009/016) is gratefully acknowledged. Y.S. is grateful to the Spanish Ministry of Science and Innovation for her grant.Salinas Soler, Y.; Martínez Mañez, R.; Marcos Martínez, MD.; Sancenón Galarza, F.; Costero Nieto, AM.; Parra Álvarez, M.; Gil Grau, S. (2012). Optical chemosensors and reagents to detect explosives. Chemical Society Reviews. 41(3):1261-1296. https://doi.org/10.1039/c1cs15173hS12611296413Furton, K. (2001). The scientific foundation and efficacy of the use of canines as chemical detectors for explosives. Talanta, 54(3), 487-500. doi:10.1016/s0039-9140(00)00546-4H�kansson, K., Coorey, R. V., Zubarev, R. A., Talrose, V. L., & H�kansson, P. (2000). Low-mass ions observed in plasma desorption mass spectrometry of high explosives. Journal of Mass Spectrometry, 35(3), 337-346. doi:10.1002/(sici)1096-9888(200003)35:33.0.co;2-7Walsh, M. (2001). Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and an electron capture detector. Talanta, 54(3), 427-438. doi:10.1016/s0039-9140(00)00541-5Sylvia, J. M., Janni, J. A., Klein, J. D., & Spencer, K. M. (2000). Surface-Enhanced Raman Detection of 2,4-Dinitrotoluene Impurity Vapor as a Marker To Locate Landmines. Analytical Chemistry, 72(23), 5834-5840. doi:10.1021/ac0006573Yinon, J. (1982). Mass spectrometry of explosives: Nitro compounds, nitrate esters, and nitramines. Mass Spectrometry Reviews, 1(3), 257-307. doi:10.1002/mas.1280010304Mathurin, J. C., Faye, T., Brunot, A., Tabet, J. C., Wells, G., & Fuché, C. (2000). High-Pressure Ion Source Combined with an In-Axis Ion Trap Mass Spectrometer. 1. Instrumentation and Applications. Analytical Chemistry, 72(20), 5055-5062. doi:10.1021/ac000171mHallowell, S. (2001). Screening people for illicit substances: a survey of current portal technology. Talanta, 54(3), 447-458. doi:10.1016/s0039-9140(00)00543-9Vourvopoulos, G. (2001). Pulsed fast/thermal neutron analysis: a technique for explosives detection. Talanta, 54(3), 459-468. doi:10.1016/s0039-9140(00)00544-0Krausa, M., & Schorb, K. (1999). Trace detection of 2,4,6-trinitrotoluene in the gaseous phase by cyclic voltammetry. Journal of Electroanalytical Chemistry, 461(1-2), 10-13. doi:10.1016/s0022-0728(98)00162-4Steinfeld, J. I., & Wormhoudt, J. (1998). EXPLOSIVES DETECTION: A Challenge for Physical Chemistry. Annual Review of Physical Chemistry, 49(1), 203-232. doi:10.1146/annurev.physchem.49.1.203Moore, D. S. (2004). Instrumentation for trace detection of high explosives. Review of Scientific Instruments, 75(8), 2499-2512. doi:10.1063/1.1771493Martínez-Máñez, R., Sancenón, F., Hecht, M., Biyikal, M., & Rurack, K. (2010). Nanoscopic optical sensors based on functional supramolecular hybrid materials. Analytical and Bioanalytical Chemistry, 399(1), 55-74. doi:10.1007/s00216-010-4198-2Moragues, M. E., Martínez-Máñez, R., & Sancenón, F. (2011). Chromogenic and fluorogenic chemosensors and reagents for anions. A comprehensive review of the year 2009. Chemical Society Reviews, 40(5), 2593. doi:10.1039/c0cs00015aMartínez-Máñez, R., & Sancenón, F. (2005). New Advances in Fluorogenic Anion Chemosensors. Journal of Fluorescence, 15(3), 267-285. doi:10.1007/s10895-005-2626-zXu, Z., Chen, X., Kim, H. N., & Yoon, J. (2010). Sensors for the optical detection ofcyanide ion. Chem. Soc. Rev., 39(1), 127-137. doi:10.1039/b907368jNolan, E. M., & Lippard, S. J. (2008). Tools and Tactics for the Optical Detection of Mercuric Ion. Chemical Reviews, 108(9), 3443-3480. doi:10.1021/cr068000qPallavicini, P., Diaz-Fernandez, Y. A., & Pasotti, L. (2009). Micelles as nanosized containers for the self-assembly of multicomponent fluorescent sensors. Coordination Chemistry Reviews, 253(17-18), 2226-2240. doi:10.1016/j.ccr.2008.11.010Que, E. L., & Chang, C. J. (2010). Responsive magnetic resonance imaging contrast agents as chemical sensors for metals in biology and medicine. Chem. Soc. Rev., 39(1), 51-60. doi:10.1039/b914348nMohr, G. J. (2004). Tailoring the sensitivity and spectral properties of a chromoreactand for the detection of amines and alcohols. Analytica Chimica Acta, 508(2), 233-237. doi:10.1016/j.aca.2003.12.005Martínez-Máñez, R., & Sancenón, F. (2003). Fluorogenic and Chromogenic Chemosensors and Reagents for Anions. Chemical Reviews, 103(11), 4419-4476. doi:10.1021/cr010421eJ. P. Agrawal and R. D.Hodgson, Organic Chemistry of Explosives, John Wiley & Sons, Chichester, 2007, ISBN-13, 978, 0-470-02967-1, HBCumming, C. J., Aker, C., Fisher, M., Fok, M., la Grone, M. J., Reust, D., … Williams, V. (2001). Using novel fluorescent polymers as sensory materials for above-ground sensing of chemical signature compounds emanating from buried landmines. IEEE Transactions on Geoscience and Remote Sensing, 39(6), 1119-1128. doi:10.1109/36.927423Toal, S. J., & Trogler, W. C. (2006). Polymer sensors for nitroaromatic explosives detection. Journal of Materials Chemistry, 16(28), 2871. doi:10.1039/b517953jMcQuade, D. T., Pullen, A. E., & Swager, T. M. (2000). Conjugated Polymer-Based Chemical Sensors. Chemical Reviews, 100(7), 2537-2574. doi:10.1021/cr9801014Zhou, Q., & Swager, T. M. (1995). Method for enhancing the sensitivity of fluorescent chemosensors: energy migration in conjugated polymers. Journal of the American Chemical Society, 117(26), 7017-7018. doi:10.1021/ja00131a031Yang, J.-S., & Swager, T. M. (1998). Porous Shape Persistent Fluorescent Polymer Films:  An Approach to TNT Sensory Materials. Journal of the American Chemical Society, 120(21), 5321-5322. doi:10.1021/ja9742996Yang, J.-S., & Swager, T. M. (1998). Fluorescent Porous Polymer Films as TNT Chemosensors:  Electronic and Structural Effects. Journal of the American Chemical Society, 120(46), 11864-11873. doi:10.1021/ja982293qYamaguchi, S., & Swager, T. M. (2001). Oxidative Cyclization of Bis(biaryl)acetylenes:  Synthesis and Photophysics of Dibenzo[g,p]chrysene-Based Fluorescent Polymers. Journal of the American Chemical Society, 123(48), 12087-12088. doi:10.1021/ja016692oZahn, S., & Swager, T. M. (2002). Three-Dimensional Electronic Delocalization in Chiral Conjugated Polymers. Angewandte Chemie International Edition, 41(22), 4225-4230. doi:10.1002/1521-3773(20021115)41:223.0.co;2-3Amara, J. P., & Swager, T. M. (2005). Synthesis and Properties of Poly(phenylene ethynylene)s with Pendant Hexafluoro-2-propanol Groups. Macromolecules, 38(22), 9091-9094. doi:10.1021/ma051562bZhao, D., & Swager, T. M. (2005). Sensory Responses in Solution vs Solid State:  A Fluorescence Quenching Study of Poly(iptycenebutadiynylene)s. Macromolecules, 38(22), 9377-9384. doi:10.1021/ma051584yThomas III, S. W., Amara, J. P., Bjork, R. E., & Swager, T. M. (2005). Amplifying fluorescent polymer sensors for the explosives taggant 2,3-dimethyl-2,3-dinitrobutane (DMNB). Chemical Communications, (36), 4572. doi:10.1039/b508408cNarayanan, A., Varnavski, O. P., Swager, T. M., & Goodson, T. (2008). Multiphoton Fluorescence Quenching of Conjugated Polymers for TNT Detection. The Journal of Physical Chemistry C, 112(4), 881-884. doi:10.1021/jp709662wChen, S., Zhang, Q., Zhang, J., Gu, J., & Zhang, L. (2010). Synthesis of two conjugated polymers as TNT chemosensor materials. Sensors and Actuators B: Chemical, 149(1), 155-160. doi:10.1016/j.snb.2010.06.007Long, Y., Chen, H., Yang, Y., Wang, H., Yang, Y., Li, N., … Liu, F. (2009). Electrospun Nanofibrous Film Doped with a Conjugated Polymer for DNT Fluorescence Sensor. Macromolecules, 42(17), 6501-6509. doi:10.1021/ma900756wChang, C.-P., Chao, C.-Y., Huang, J. H., Li, A.-K., Hsu, C.-S., Lin, M.-S., … Su, A.-C. (2004). Fluorescent conjugated polymer films as TNT chemosensors. Synthetic Metals, 144(3), 297-301. doi:10.1016/j.synthmet.2004.04.003Levitsky, I. A., Euler, W. B., Tokranova, N., & Rose, A. (2007). Fluorescent polymer-porous silicon microcavity devices for explosive detection. Applied Physics Letters, 90(4), 041904. doi:10.1063/1.2432247Chen, L., McBranch, D., Wang, R., & Whitten, D. (2000). Surfactant-induced modification of quenching of conjugated polymer fluorescence by electron acceptors: applications for chemical sensing. Chemical Physics Letters, 330(1-2), 27-33. doi:10.1016/s0009-2614(00)00970-2Rose, A., Zhu, Z., Madigan, C. F., Swager, T. M., & Bulović, V. (2005). Sensitivity gains in chemosensing by lasing action in organic polymers. Nature, 434(7035), 876-879. doi:10.1038/nature03438Tamao, K., Uchida, M., Izumizawa, T., Furukawa, K., & Yamaguchi, S. (1996). Silole Derivatives as Efficient Electron Transporting Materials. Journal of the American Chemical Society, 118(47), 11974-11975. doi:10.1021/ja962829cSohn, H., Huddleston, R. R., Powell, D. R., West, R., Oka, K., & Yonghua, X. (1999). An Electroluminescent Polysilole and Some Dichlorooligosiloles. Journal of the American Chemical Society, 121(12), 2935-2936. doi:10.1021/ja983350iOhshita, J., & Kunai, A. (1998). Polymers with alternating organosilicon and π-conjugated units. Acta Polymerica, 49(8), 379-403. doi:10.1002/(sici)1521-4044(199808)49:83.0.co;2-zToal, S. J., Magde, D., & Trogler, W. C. (2005). Luminescent oligo(tetraphenyl)silole nanoparticles as chemical sensors for aqueous TNT. Chemical Communications, (43), 5465. doi:10.1039/b509404fSohn, H., Sailor, M. J., Magde, D., & Trogler, W. C. (2003). Detection of Nitroaromatic Explosives Based on Photoluminescent Polymers Containing Metalloles. Journal of the American Chemical Society, 125(13), 3821-3830. doi:10.1021/ja021214eSanchez, J. C., DiPasquale, A. G., Rheingold, A. L., & Trogler, W. C. (2007). Synthesis, Luminescence Properties, and Explosives Sensing with 1,1-Tetraphenylsilole- and 1,1-Silafluorene-vinylene Polymers. Chemistry of Materials, 19(26), 6459-6470. doi:10.1021/cm702299gSanchez, J. C., Urbas, S. A., Toal, S. J., DiPasquale, A. G., Rheingold, A. L., & Trogler, W. C. (2008). Catalytic Hydrosilylation Routes to Divinylbenzene Bridged Silole and Silafluorene Polymers. Applications to Surface Imaging of Explosive Particulates. Macromolecules, 41(4), 1237-1245. doi:10.1021/ma702274cSanchez, J. C., & Trogler, W. C. (2008). Efficient blue-emitting silafluorene–fluorene-conjugated copolymers: selective turn-off/turn-on detection of explosives. Journal of Materials Chemistry, 18(26), 3143. doi:10.1039/b802623hLiu, J., Zhong, Y., Lam, J. W. Y., Lu, P., Hong, Y., Yu, Y., … Tang, B. Z. (2010). Hyperbranched Conjugated Polysiloles: Synthesis, Structure, Aggregation-Enhanced Emission, Multicolor Fluorescent Photopatterning, and Superamplified Detection of Explosives. Macromolecules, 43(11), 4921-4936. doi:10.1021/ma902432mLu, P., Lam, J. W. Y., Liu, J., Jim, C. K. W., Yuan, W., Xie, N., … Tang, B. Z. (2010). Aggregation-Induced Emission in a Hyperbranched Poly(silylenevinylene) and Superamplification in Its Emission Quenching by Explosives. Macromolecular Rapid Communications, 31(9-10), 834-839. doi:10.1002/marc.200900794Liu, Y., Mills, R. C., Boncella, J. M., & Schanze, K. S. (2001). Fluorescent Polyacetylene Thin Film Sensor for Nitroaromatics. Langmuir, 17(24), 7452-7455. doi:10.1021/la010696pToy, L. G., Nagai, K., Freeman, B. D., Pinnau, I., He, Z., Masuda, T., … Yampolskii, Y. P. (2000). Pure-Gas and Vapor Permeation and Sorption Properties of Poly[1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene] (PTMSDPA). Macromolecules, 33(7), 2516-2524. doi:10.1021/ma991566eSaxena, A., Fujiki, M., Rai, R., & Kwak, G. (2005). Fluoroalkylated Polysilane Film as a Chemosensor for Explosive Nitroaromatic Compounds. Chemistry of Materials, 17(8), 2181-2185. doi:10.1021/cm048319wSaxena, A., Rai, R., Kim, S.-Y., Fujiki, M., Naito, M., Okoshi, K., & Kwak, G. (2006). Weak noncovalent Si···FC interactions stabilized fluoroalkylated rod-like polysilanes as ultrasensitive chemosensors. Journal of Polymer Science Part A: Polymer Chemistry, 44(17), 5060-5075. doi:10.1002/pola.21607Toal, S. J., Sanchez, J. C., Dugan, R. E., & Trogler, W. C. (2007). Visual Detection of Trace Nitroaromatic Explosive Residue Using Photoluminescent Metallole-Containing Polymers. Journal of Forensic Sciences, 52(1), 79-83. doi:10.1111/j.1556-4029.2006.00332.xStringer, R. C., Gangopadhyay, S., & Grant, S. A. (2010). Detection of Nitroaromatic Explosives Using a Fluorescent-Labeled Imprinted Polymer. Analytical Chemistry, 82(10), 4015-4019. doi:10.1021/ac902838cLi, J., Kendig, C. E., & Nesterov, E. E. (2007). Chemosensory Performance of Molecularly Imprinted Fluorescent Conjugated Polymer Materials. Journal of the American Chemical Society, 129(51), 15911-15918. doi:10.1021/ja0748027Bunte, G., Hürttlen, J., Pontius, H., Hartlieb, K., & Krause, H. (2007). Gas phase detection of explosives such as 2,4,6-trinitrotoluene by molecularly imprinted polymers. Analytica Chimica Acta, 591(1), 49-56. doi:10.1016/j.aca.2007.02.014Zhang, X., & Jenekhe, S. A. (2000). Electroluminescence of Multicomponent Conjugated Polymers. 1. Roles of Polymer/Polymer Interfaces in Emission Enhancement and Voltage-Tunable Multicolor Emission in Semiconducting Polymer/Polymer Heterojunctions. Macromolecules, 33(6), 2069-2082. doi:10.1021/ma991913kHou, S., Ding, M., & Gao, L. (2003). Synthesis and Properties of Polyquinolines and Polyanthrazolines Containing Pyrrole Units in the Main Chain. Macromolecules, 36(11), 3826-3832. doi:10.1021/ma025768dKim, T. H., Kim, H. J., Kwak, C. G., Park, W. H., & Lee, T. S. (2006). Aromatic oxadiazole-based conjugated polymers with excited-state intramolecular proton transfer: Their synthesis and sensing ability for explosive nitroaromatic compounds. Journal of Polymer Science Part A: Polymer Chemistry, 44(6), 2059-2068. doi:10.1002/pola.21319Nie, H., Zhao, Y., Zhang, M., Ma, Y., Baumgarten, M., & Müllen, K. (2011). Detection of TNT explosives with a new fluorescent conjugated polycarbazole polymer. Chem. Commun., 47(4), 1234-1236. doi:10.1039/c0cc03659eQin, A., Lam, J. W. Y., Tang, L., Jim, C. K. W., Zhao, H., Sun, J., & Tang, B. Z. (2009). Polytriazoles with Aggregation-Induced Emission Characteristics: Synthesis by Click Polymerization and Application as Explosive Chemosensors. Macromolecules, 42(5), 1421-1424. doi:10.1021/ma8024706Kumar, A., Pandey, M. K., Anandakathir, R., Mosurkal, R., Parmar, V. S., Watterson, A. C., & Kumar, J. (2010). Sensory response of pegylated and siloxanated 4,8-dimethylcoumarins: A fluorescence quenching study by nitro aromatics. Sensors and Actuators B: Chemical, 147(1), 105-110. doi:10.1016/j.snb.2010.02.004Nguyen, H. H., Li, X., Wang, N., Wang, Z. Y., Ma, J., Bock, W. J., & Ma, D. (2009). Fiber-Optic Detection of Explosives Using Readily Available Fluorescent Polymers. Macromolecules, 42(4), 921-926. doi:10.1021/ma802460qAlbert, K. J., & Walt, D. R. (2000). High-Speed Fluorescence Detection of Explosives-like Vapors. Analytical Chemistry, 72(9), 1947-1955. doi:10.1021/ac991397wGao, D., Wang, Z., Liu, B., Ni, L., Wu, M., & Zhang, Z. (2008). Resonance Energy Transfer-Amplifying Fluorescence Quenching at the Surface of Silica Nanoparticles toward Ultrasensitive Detection of TNT. Analytical Chemistry, 80(22), 8545-8553. doi:10.1021/ac8014356Fang, Q., Geng, J., Liu, B., Gao, D., Li, F., Wang, Z., … Zhang, Z. (2009). Inverted Opal Fluorescent Film Chemosensor for the Detection of Explosive Nitroaromatic Vapors through Fluorescence Resonance Energy Transfer. Chemistry - A European Journal, 15(43), 11507-11514. doi:10.1002/chem.200901488Geng, J., Liu, P., Liu, B., Guan, G., Zhang, Z., & Han, M.-Y. (2010). A Reversible Dual-Response Fluorescence Switch for the Detection of Multiple Analytes. Chemistry - A European Journal, 16(12), 3720-3727. doi:10.1002/chem.200902721Yang, J., Aschemeyer, S., Martinez, H. P., & Trogler, W. C. (2010). Hollow silica nanospheres containing a silafluorene–fluorene conjugated polymer for aqueous TNT and RDX detection. Chemical Communications, 46(36), 6804. doi:10.1039/c0cc01906bFeng, J., Li, Y., & Yang, M. (2010). Conjugated polymer-grafted silica nanoparticles for the sensitive detection of TNT. Sensors and Actuators B: Chemical, 145(1), 438-443. doi:10.1016/j.snb.2009.12.056Tao, S., Shi, Z., Li, G., & Li, P. (2006). Hierarchically Structured Nanocomposite Films as Highly Sensitive Chemosensory Materials for TNT Detection. ChemPhysChem, 7(9), 1902-1905. doi:10.1002/cphc.200600185Tao, S., Yin, J., & Li, G. (2008). High-performance TNT chemosensory materials based on nanocomposites with bimodal porous structures. Journal of Materials Chemistry, 18(40), 4872. doi:10.1039/b802486cTao, S., Li, G., & Zhu, H. (2006). Metalloporphyrins as sensing elements for the rapid detection of trace TNT vapor. Journal of Materials Chemistry, 16(46), 4521. doi:10.1039/b606061gTao, S., & Li, G. (2007). Porphyrin-doped mesoporous silica films for rapid TNT detection. Colloid and Polymer Science, 285(7), 721-728. doi:10.1007/s00396-007-1643-7Yildirim, A., Budunoglu, H., Deniz, H., O. Guler, M., & Bayindir, M. (2010). Template-Free Synthesis of Organically Modified Silica Mesoporous Thin Films for TNT Sensing. ACS Applied Materials & Interfaces, 2(10), 2892-2897. doi:10.1021/am100568cLi, H., Wang, J., Pan, Z., Cui, L., Xu, L., Wang, R., … Jiang, L. (2011). Amplifying fluorescence sensing based on inverse opal photonic crystal toward trace TNT detection. J. Mater. Chem., 21(6), 1730-1735. doi:10.1039/c0jm02554bTao, S., Li, G., & Yin, J. (2007). Fluorescent nanofibrous membranes for trace detection of TNT vapor. Journal of Materials Chemistry, 17(26), 2730. doi:10.1039/b618122hNaddo, T., Che, Y., Zhang, W., Balakrishnan, K., Yang, X., Yen, M., … Zang, L. (2007). Detection of Explosives with a Fluorescent Nanofibril Film. Journal of the American Chemical Society, 129(22), 6978-6979. doi:10.1021/ja070747qContent, S., Trogler, W. C., & Sailor, M. J. (2000). Detection of Nitrobenzene, DNT, and TNT Vapors by Quenching of Porous Silicon Photoluminescence. Chemistry - A European Journal, 6(12), 2205-2213. doi:10.1002/1521-3765(20000616)6:123.0.co;2-aKang, J., Ding, L., Lü, F., Zhang, S., & Fang, Y. (2006). Dansyl-based fluorescent film sensor for nitroaromatics in aqueous solution. Journal of Physics D: Applied Physics, 39(23), 5097-5102. doi:10.1088/0022-3727/39/23/030Zhang, S., Lü, F., Gao, L., Ding, L., & Fang, Y. (2007). Fluorescent Sensors for Nitroaromatic Compounds Based on Monolayer Assembly of Polycyclic Aromatics. Langmuir, 23(3), 1584-1590. doi:10.1021/la062773sHe, G., Zhang, G., Lü, F., & Fang, Y. (2009). Fluorescent Film Sensor for Vapor-Phase Nitroaromatic Explosives via Monolayer Assembly of Oligo(diphenylsilane) on Glass Plate Surfaces. Chemistry of Materials, 21(8), 1494-1499. doi:10.1021/cm900013fGoodpaster, J. V., & McGuffin, V. L. (2001). Fluorescence Quenching as an Indirect Detection Method for Nitrated Explosives. Analytical Chemistry, 73(9), 2004-2011. doi:10.1021/ac001347nHughes, A. D., Glenn, I. C., Patrick, A. D., Ellington, A., & Anslyn, E. V. (2008). A Pattern Recognition Based Fluorescence Quenching Assay for the Detection and Identification of Nitrated Explosive Analytes. Chemistry - A European Journal, 14(6), 1822-1827. doi:10.1002/chem.200701546Malashikhin, S., & Finney, N. S. (2008). Fluorescent Signaling Based on Sulfoxide Profluorophores: Application to the Visual Detection of the Explosive TATP. Journal of the American Chemical Society, 130(39), 12846-12847. doi:10.1021/ja802989vFocsaneanu, K.-S., & Scaiano, J. C. (2005). Potential analytical applications of differential fluorescence quenching: pyrene monomer and excimer emissions as sensors for electron deficient molecules. Photochemical & Photobiological Sciences, 4(10), 817. doi:10.1039/b505249aLee, Y. H., Liu, H., Lee, J. Y., Kim, S. H., Kim, S. K., Sessler, J. L., … Kim, J. S. (2010). Dipyrenylcalix[4]arene-A Fluorescence-Based Chemosensor for Trinitroaromatic Explosives. Chemistry - A European Journal, 16(20), 5895-5901. doi:10.1002/chem.200903439Jian, C., & Seitz, W. R. (1990). Membrane for in situ optical detection of organic nitro compounds based on fluorescence quenching. Analytica Chimica Acta, 237, 265-271. doi:10.1016/s0003-2670(00)83928-8Vijayakumar, C., Tobin, G., Schmitt, W., Kim, M.-J., & Takeuchi, M. (2010). Detection of explosive vapors with a charge transfer molecule: self-assembly assisted morphology tuning and enhancement in sensing efficiency. Chemical Communications, 46(6), 874. doi:10.1039/b921520dZyryanov, G. V., Palacios, M. A., & Anzenbacher, P. (2008). Simple Molecule-Based Fluorescent Sensors for Vapor Detection of TNT. Organic Letters, 10(17), 3681-3684. doi:10.1021/ol801030uCavaye, H., Shaw, P. E., Wang, X., Burn, P. L., Lo, S.-C., & Meredith, P. (2010). Effect of Dimensionality in Dendrimeric and Polymeric Fluorescent Materials for Detecting Explosives. Macromolecules, 43(24), 10253-10261. doi:10.1021/ma102369qPonnu, A., & Anslyn, E. V. (2010). A fluorescence-based cyclodextrin sensor to detect nitroaromatic explosives. Supramolecular Chemistry, 22(1), 65-71. doi:10.1080/10610270903378032Zhang, C., Che, Y., Yang, X., Bunes, B. R., & Zang, L. (2010). Organic nanofibrils based on linear carbazole trimer for explosive sensing. Chemical Communications, 46(30), 5560. doi:10.1039/c0cc01258kLi, Z., Dong, Y. Q., Lam, J. W. Y., Sun, J., Qin, A., Häußler, M., … Tang, B. Z. (2009). Functionalized Siloles: Versatile Synthesis, Aggregation-Induced Emission, and Sensory and Device Applications. Advanced Functional Materials, 19(6), 905-917. doi:10.1002/adfm.20

Cross-Reactive Sensor Arrays for the Detection of Peptides in Aqueous Solution by Fluorescence Spectroscopy

A simple but powerful method for the sensing of peptides in aqueous solution has been developed. The transition-metal complexes [PdCl2(en)], [{RhCl2Cp*}2], and [{RuCl2(p-cymene)} 2] were combined with six different fluorescent dyes to build a cross-reactive sensor array. The fluorescence response of the individual sensor units was based on competitive complexation reactions between the peptide analytes and the fluorescent dyes. The collective response of the sensor array in a time-resolved fashion was used as an input for multivariate analyses. A sensor array comprised of only six metal-dye combinations was able to differentiate ten different dipeptides in buffered aqueous solution at a concentration of 50 uM. Furthermore, the cross-reactive sensor could be used to obtain information about the identity and the quantity of the pharmacologically interesting dipeptides carnosine and homocarnosine in a complex biological matrix, such as deproteinized human blood serum. The sensor array was also able to sense longer peptides, which was demonstrated by differentiating mixtures of the nonapeptide bradykinin and the decapeptide kallidin