title: Confeito-like assembly of organosilicate-caged fluorophores: ultrabright suprananoparticles for fluorescence imaging.
abstract: We report ultrabright, photostable, sub-25 nm nanoparticle agglomerates (suprananoparticles) assembled from a few hundred 3.3 ± 0.9 nm units, each hosting on average a single rhodamine 6G (Rh6G) dye molecule encased in a thin organosilicate cage. These individual Rh6G-doped nanoparticle (DOSNP) units consist of a hydrophobic core containing the dye and an ultrathin, conformal silicate shell modified by CO(2) plasma to confer a beneficial 'cage effect' as well as surface hydrophilicity. The isolation of the dye within individual DOSNP units in the final 22 ± 5 nm agglomerate avoids dimerization and related spontaneous molecular interactions that otherwise lead to self-quenching in closely co-localized fluorophores. The resulting suprananoparticles are over 200 times brighter than the free Rh6G molecules in the same volume. There is no observable dye leaching, and the labels are 20-fold more resistant to photobleaching than free Rh6G in solution. We demonstrate the attractive features of DOSNPs as labels in bioimaging applications.
authors.affiliation: Department of Electrical Engineering, University of Missouri, Columbia, MO 65211, USA.
authors.forename: Sangho
authors.initials: S
authors.lastname: Bok
authors.forename: Venumadhav
authors.initials: V
authors.lastname: Korampally
authors.forename: Luis
authors.initials: L
authors.lastname: Polo-Parada
authors.forename: Vamsi
authors.initials: V
authors.lastname: Mamidi
authors.forename: Gary A
authors.initials: GA
authors.lastname: Baker
authors.forename: Keshab
authors.initials: K
authors.lastname: Gangopadhyay
authors.forename: William R
authors.initials: WR
authors.lastname: Folk
authors.forename: Purnendu K
authors.initials: PK
authors.lastname: Dasgupta
authors.forename: Shubhra
authors.initials: S
authors.lastname: Gangopadhyay
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry*; D010316:Particle Size; D038761:Photobleaching; D012235:Rhodamines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D017646:Organosilicon Compounds; D012235:Rhodamines; C026188:rhodamine 6G