Optical sensing quantum dot-labeled polyacrolein particles prepared by layer-by-layer deposition technique

• Published in: Journal of colloid and interface science 2011-05, Vol.357 (2), p.265-272
• Main Authors: Generalova, Alla N., Oleinikov, Vladimir A., Zarifullina, Margarita M., Lankina, Ekaterina V., Sizova, Svetlana V., Artemyev, Michail V., Zubov, Vitali P.
• Format: Article
• Language: English
• Subjects: Acrolein - chemistry; Animals; barium; bovine serum albumin; Cadmium selenides; calcium; cations; Cattle; cobalt; copper; Copper(II) detection; Deposition; Detection; detection limit; electrolytes; electrostatic interactions; Fluorescence; Hydrogen-Ion Concentration; hydrophilicity; Immobilized Proteins - chemistry; magnesium; Models, Biological; Multiplexing; Nanocrystals; Nanoparticles - chemistry; pH-sensitivity; Polyacrolein particles; Polyelectrolytes; polymers; Polymers - chemistry; Quantum Dots; Semiconductors; Serum albumin; Serum Albumin, Bovine - chemistry; Spectrometry, Fluorescence; Surface Properties; zinc
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2011.02.002

Tailored QD loading as a part of polyelectrolyte layers makes it possible to design polymer particles with pH-dependent fluorescence intensity and use these particles for sensitive and selective detection of copper(II) ion. [Display omitted] ► Fluorescent polymer particles are prepared by LbL technique. ► Close to surface QD deposition results in pH-sensitivity of particle fluorescence. ► Bioligands as outermost shell determine the fluorescence properties of particles. ► The outer shell of BSA allows the particle design for detection of Cu(II) ion. Optical sensing polymer particles with tailored semiconductor nanocrystal (QD) loading are prepared by layer-by-layer deposition technique (LbL). Polyacrolein particles of 1.2μm diameter are used as solid support for deposition of hydrophilic CdSe/ZnS nanocrystal/polyelectrolyte multilayers formed by electrostatic interactions. The pH-dependent fluorescence of QDs and pH-dependent conformations of polyelectrolytes, which likely passivate the surface state of nanocrystals, allow a creation of both mono- and multiplex coded polymer particles with pH-dependent fluorescence intensity. Bovine serum albumin (BSA) as outermost layer makes it possible to design the optical sensing polymer particles with reversibly responded fluorescence at pH variations. The fluorescence of such polymer particles with BSA outer layer is sensitive to copper(II) ion while the fluorescence of these particles is practically insensitive to the other divalent cations (Zn2+, Ca2+, Ba2+, Co2+, Mg2+). The detection limit of Cu2+ is about 15nM. Adaptation of LbL method to prepare QD-labeled polymer particles with enhanced complexity (e.g. several types of QDs, multiple biofunctionality) is expected to open new opportunities in biotechnological applications.