Bright, non-blinking, and less-cytotoxic SiO2 beads with multiple CdSe/ZnS nanocrystals

Abstract

A method including surface silanization, phase transfer and self-assembly, and SiO2 shell growth has been developed to incorporate multiple hydrophobic CdSe/ZnS nanocrystals into SiO2 beads where they are well suited for bio-application due to their high brightness, less-cytotoxic, and non-blinking nature.

Controlled self-assembly of hydrophobic quantum dots through silanization

“…The selfassembly of the QDs can be created in this two-phase system by adjusting the QD surface ligand. In previous papers, we successfully encapsulated hydrophobic and hydrophilic QDs in SiO 2 beads by using such emulsions [22][23][24][25]. With controlling the surface chemistry of the QDs, these SiO 2 beads revealed high photoluminescence (PL) efficiencies.…”

“…Because the hydrolysis and condensation occurred slowly in an aqueous solvent or oil-water systems, the control of sol-gel processes provided an ideal approach to assemble QDs. Recently, we found out partially hydrolyzed silicon alkoxides have an ability to replace the hydrophobic capping agent on the surface of QDs [22]. A controlled condensation of SiO 2 monomers was utilized for the self-assembly of the QDs in a small SiO 2 bead.…”

Facile synthesis of wormlike quantum dots-encapsulated nanoparticles and their controlled surface functionalization for effective bioapplications

“…Such kinds of gene carriers are mostly fabricated via appropriate surface functionalization with cationic polymers [23][24][25][26][27] or small molecules [8,28]. Furthermore, cellular imaging might be simultaneously achieved in the same nanostructure owing to the optical properties of QDs [24][25][26].…”

“…QD-based gene carriers are promising for cancer therapy [23]. Such kinds of gene carriers are mostly fabricated via appropriate surface functionalization with cationic polymers [23][24][25][26][27] or small molecules [8,28].…”

Surface Treatment of Zinc Oxide Nanoparticles by Silica Coating and Evaluation of Their Dispersibility and Photoluminescent Properties

“…Thus ZnO seems to be suitable for bioimaging applications. Organic dyes or Quantum dots are studied as fluorescent labeling reagents for bioimaging [6][7][8][9][10][11][12][13], but they have photobleaching behavior or toxicity for human body, hence ZnO is considered to be a candidate as the fluorescent labeling reagent which does not have these demerits. ZnO have been used as a fluorescent material using its broad (around 400 nm-600 nm wavelength) emissions, which are generated from oxygen vacancies (V O ), vacant zinc (V Zn ), zinc interstitials (Zn i ), anti-site defects (Zn O ), their ionized counterparts and complexes, and other defects in the crystalline lattices of ZnO, which is collectively called defect emission.…”