title: Complex catalytic colloids on the basis of firefly luciferase as optical nanosensor platform.
abstract: In the present work the layer-by-layer nano-assembly technique was used for the development of complex catalytic microparticles on the basis of firefly luciferase (FL). FL films containing 1, 2, or 3 monolayers were assembled on silver electrode QCM-resonators and on 520-nm diameter sulfonated polystyrene latex by alternate adsorption of FL and polycations using electrostatic interactions for the interlayer interaction. The assembly process was studied with quartz crystal microbalance, UV-vis spectroscopy, and microelectrophoresis (surface potential). Structural studies of the resulting multilayers confirmed stepwise deposition of FL and cationic poly(dimethyldiallyl ammonium chloride) with a bilayer thickness of 14 nm; a systematic shift of the surface potential from +28 mV for poly(dimethyldiallyl ammonium chloride) to -14 mV for luciferase outermost layer was established. The functionality and stability of the biocolloids were demonstrated by monitoring the intensity of the light emission. Factors influencing the light emitted upon catalytic activity of FL such as the number of luciferase layers in the film and polyion layer at the outermost layer were studied.
authors.affiliation: Department of Biophysical M&O Science and Technologies, University of Genoa, Corso Europa 30, 16132 Genoa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Pastorino
authors.forename: Sandeep
authors.initials: S
authors.lastname: Disawal
authors.forename: Claudio
authors.initials: C
authors.lastname: Nicolini
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Lvov
authors.forename: Victor V
authors.initials: VV
authors.lastname: Erokhin
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis* / Q000737:chemistry; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002384:Catalysis; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry; D001517:Coleoptera / Q000201:enzymology; D003102:Colloids / Q000737:chemistry; D003460:Crystallization / Q000379:methods*; D008156:Luciferases / Q000737:chemistry*; D049449:Luminescence; D008863:Microspheres; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D010783:Photometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D003102:Colloids; D000255:Adenosine Triphosphate; D008156:Luciferases