Almdal, K.

Jakobsen, I.

Scharff-Poulsen, A.M.

Sun, H.

Online Research Database In Technology

  General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.   Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal  If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.         Downloaded from orbit.dtu.dk on: Oct 25, 2019Nanometer sized fluorescent gel particles for detection of metabolites in living cellsAlmdal, K.; Sun, H.; Jakobsen, I.; Scharff-Poulsen, A.M.Publication date:2006Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Almdal, K., Sun, H., Jakobsen, I., & Scharff-Poulsen, A. M. (2006). Nanometer sized fluorescent gel particles fordetection of metabolites in living cells. Abstract from Nordic Polymer Days 2006, Copenhagen, Denmark.  Nanometer sized fluorescent gel particles for detection of metabolites in living cells. Kristoffer Almdal1, Honghao Sun1, Iver Jakobsen2, Anne Marie Scharff-Poulsen2. Affiliations (1 The Danish Polymer Centre, Risø, Risø National Laboratory, Roskilde, Denmark; 2 The Biosystems Department, Risø National Laboratory, Roskilde, Denmark) Particles with embedded fluorescent dyes have potential as nanosensors for the detection of spatially and time resolved measurements of metabolite concentrations in living cells. The quantification of the potential analyte can be based on either ratiometric detection of fluorescence from two dyes or on a reversible analyte concentration-dependent change in Fluorescence Resonance Energy Transfer (FRET) efficiency. For ratiometric detection the dyes are chosen such that the fluorescence of one dye is a function of an analyte concentration whereas the fluorescence of the other dye is independent of variations in the medium. For FRET based detection one molecule containing two fluorophores which have an analyte concentration dependent conformation is needed. International collaborators1 have developed methods that allow metabolite binding proteins from various bacteria to be inserted between fluorescent proteins where it serves like a hinge (FLIP-proteins). This configuration makes the FRET signal dependent on the concentration of the targeted metabolite. As an example maltose sensitive FLIP-proteins with a range of sensitivities have been developed. The present contribution focuses on incorporation of such ratiometric and FRET based system in hydrogel particles. In the Figure is shown the pH-response of hydrogel based (acryl amide) nanosensors particles with both a reference and reporter dye for pH covalently bonded to the inte-rior of the particle. These particles function as ratiometric pH-sensors. The acrylamide gel particles were synthesized in water in oil (hexane) inverse micelles. Prepared nanoparticles were characterized with a variety of methods including dynamic light scattering, size exclusion chromatography and small angle X-ray scattering. The particle sizes obtained are in the 20-80 nm range. The contribution will focus on the challenges involved in utilising inverse microemulsions for synthesis in as well as in utilising such particles as nanosensors.                                                  1 This work is part of an international collaboration between Risø National Laboratory, Department of Plant Biology, The Carnegie institution of Washington, Standford, USA and Institute for Plant Biotechnology, University of Stellenbosch, Stellenbosch, Republic of South Africa financed by the Human Frontier Science Programme (Grant: RGP0041/2004-C) 5,0 5,5 6,0 6,5 7,0 7,5 8,0 8,5 9,00,51,01,52,02,53,03,54,04,5A  Fluorescence emission ratio FA/Rh B(500-540nm/560-600nm)pH A pH calibration curve of the pH sensing nano-particles. Particles were suspended (1mg/mL) in 10mM phosphate buffer at different pH values. The fluoresceinamine (FA) and N-acrylamide-N’-rhodamine B thiourea (Rh B) dyes were effectively excited at 488nm and 543nm, re-spectively. The ratio between the fluorescence emission intensities of FA (500-540nm) and Rh B (560-600nm) was plotted against pH of the solution. 

Nanometer sized fluorescent gel particles for detection of metabolites in living cells

https://orbit.dtu.dk/files/174578276/pol_3_2006.pdf

Nanometer sized fluorescent gel particles for detection of metabolites in living cells

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology