Rhodamine B doped silica nanoparticle labels for protein microarray detection

Abstract

A core-shell Rhodamine B-doped SiO 2 nanoparticle was synthesized and its fluorescent intensity was found to be 1000 times higher than that of individual Rhodamine B molecule. The doped nanoparticles were further conjugated with streptavidin and the resulting nanoparticles were used in the detection of reverse-phase protein microarrays, in which human IgG of various concentrations was first immobilized on aldehyde-modified glass slides and then biotinlyated goat anti human IgG as well as the labeled nanoparticles were sequentially conjugated. The calibration curve is linear over the range from 800 fg to 500 pg and the limit of detection is 100 fg, which is 8 times lower than that of streptavidin-labeled Cy3 fluorescent dyes. The dyedoped SiO 2 nanoparticles show potentials for the protein array detection. Rhodamine B, SiO 2 nanoparticles, protein detection, protein microarrays

Fluorescent nanoparticles for chemical and biological sensing

“…Surface modified amine and carboxyl groups can also be introduced after polymerization has been initiated by adding appropriately terminated silane reagents [27]. As another type of hosting material, polymer or phospholipid also provide a diversity and biocompatible matrix for dye-encapsulation [28]. For instance, the PEBBLEs (Probes Encapsulated By Biologically Localized Embedding) nanosensors, developed by Kopelman et al, were fabricated from polyacrylamide, decylmethacrylate or sol-gel silica [29].…”

Polymeric nanoparticles for optical sensing

“…Since hundreds of dye molecules can be embedded in one NP, this will enhance the signal recognition, allowing ultrasensitive detection Wang et al, 2010a). However, the amount of dye embedded must be carefully chosen to avoid self-quenching, typically occurring in many organic dyes at high concentrations (Knopp et al, 2009).…”