| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 600810 | Colloids and Surfaces B: Biointerfaces | 2012 | 7 Pages |
A variety of fluorescent nanoparticles have been developed for demanding applications such as optical biosensing and fluorescence imaging in live cells. Silica-based fluorescent nanoparticles offer diverse advantages for biological applications. For example, they can be used as labeling probes due to their low toxicity, high sensitivity, resolution, and stability. In this research, a new class of highly fluorescent, efficient nanoparticles composed of a newly synthesized poly[di(2-methoxy-5-(2-ethylhexyloxy))-2,7-(9,9-dioctyl-9H-fluorene)] (PDDF) core and a silica shell (designated as PDDF@SiO2) were prepared using a simple reverse micelle method, and their fluorescent properties were evaluated using methods such as single-dot photoluminescence measurements. The enhanced photostability of the particles and their potential applications for bioanalysis are discussed in this article. The morphology, size, and fluorescent properties for prepared PDDF@SiO2 nanoparticles were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and photoluminescence spectroscopy. The prepared particles size, which was approximately 60 nm, resulted in an excellent colloidal stability in a physiological environment. The photobleaching dynamics, total numbers of emitted photons (TNEP) and statistical measurements of individual nanoparticles were observed using laser scanning fluorescence microscopy to assess the structure and photostability of PDDF@SiO2 nanoparticles. Additionally, PDDF@SiO2 nanoparticles were used in cell toxicity and permeation tests for biological analyses, demonstrating a great potential for use as powerful, novel materials within the emerging fields of biosensing and biomedical engineering.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Fluorescent nanoparticles composed of fluorene copolymer and silica shell are developed for use as highly photostable nano-biomaterials. ► From the results of photobleaching dynamics, TNEP measurements and statistics of individual nanoparticles, we identified many isolated fluorescent moieties in single nanoparticles. ► Bleaching of individual fluorophores caused exponential decay and a log-normal distribution indicates that it does not consist of a single emitter; rather, it consists of a set of independent fluorophores. ► Greater stability and brightness are attributed to exciton isolation among the fluorescent moieties in a single nanoparticle.
