Multiple dye-doped silica cross-linked micellar nanoparticles for colour-tuneable sensing of cysteine in an aqueous media and living cells

Dye doped concentric shell nanoparticles for enhanced photophysical performance of downconverting light emitting diodes

In this study, we examined the potential for perylene dye doped nanoparticles to enhance Light Emitting Diodes (LED) efficacy by minimizing π-π intermolecular aggregation, and enhancing photoluminescence and photostability of the dye molecules in the solid state. Towards this end, we encapsulated perylene dyes, suitably modified with a reactive silica precursor, into silica nanoparticles within a silica-dye-silica concentric layered shell. We found that the fluorescent yield was higher when the dye was embedded in a buried concentric shell within the silica nanoparticles (NPs) compared to an undoped shell/dye doped core nanoparticle morphology or unencapsulated dye with the same net dye concentration in solution. A strong dependence of relative quantum yield on dye doping concentration in the silica-dye-silica nanoparticles was observed. The uniform ∼ 100 nm large silica-dye-silica layered nanoparticles were used to prepare transparent dye doped silica nanoparticle/silicone nanocomposites. Dye doped silica nanoparticle/silicone nanocomposites exhibited higher photostability than the unencapsulated dye samples during long time aging tests under a blue LED with a wavelength of 455 nm at 300 ± 3% mA for 24 h. Novel dye doped layered silica NPs and their nanocomposites offer scope for developing organic luminescent materials into efficient and color-tunable light emitters for low-cost display, lighting, and optical communication applications.

Novel applications of perovskite oxide via catalytic peroxymonosulfate advanced oxidation in aqueous systems for trace L-cysteine detection

Perovskite oxides offer new opportunities in wastewater treatment via catalytic oxidation. Herein, we report a new application of perovskite oxides for biological detection via catalytic decolourisation and colorimetric determination. The presence of trace biomolecules in an aqueous system would interfere the decolourisation process of dyes, where the decolourisation rate is quantitatively correlated to the biomolecular concentration. In this work, trace L-cysteine (Cys) detection was demonstrated on the basis of a Ag-Ba_0.5Sr_0.5Co_0.75Fe_0.2O_3-δ (Ag-BSCF)/peroxymonosulfate/textile dye system. Thiol-containing cysteine can bind to Ag, Co and Fe atoms, therefore shielding the catalytic performance of the perovskite in degradation of dye solutions. Such a cost-effective biosensor system presents an excellent linear response in Cys concentration ranging from nM to μM.