Functionalized Plasmonic−Fluorescent Nanoparticles for Imaging and Detection

Abstract

Plasmonic-fluorescent composite nanoparticles are considered as unique, multifunctional nanoprobes for plasmon-and fluorescence-based imaging and detection. However, their synthesis is challenging due to fluorescence quenching of the fluorophore by plasmonic particles and most of the successful methods produce composite particles of large size (diameter > 50 nm), which limit their wider applications. Here we report 20-30 nm diameter plasmonic-fluorescent composite nanoparticles with reasonable fluorescence quantum yield (12-16%). These particles are composed of 3-6 nm diameter Au/Ag cores and fluorescein-incorporated polymeric shells. They have high water solubility, good colloidal stability, stable fluorescence properties, and are amenable in deriving various functional nanoprobes. Different functional nanoprobes are derived from these composites and successfully used for fluorescence-based cell labeling as well as plasmon-based detection applications.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

“…[1][2][3][4] Recently, MEF has attracted considerable interest, since it can be exploited in several fluorescence-based biomedical applications, 5 such as DNA 6,7 and RNA 8 sensing, immunoassays, 9,10 or fluorescence-based imaging. 11,12 Amplification of light from fluorophores through MEF is a promising strategy for significantly improving detection sensitivity and contrast enhancement, hence maximising the potential of fluorescence-based technologies in bioapplications. 5 For MEF to occur, fluorophores need to be positioned in close proximity to the metallic nanoparticle surface.…”

Probing the colloidal gold nanoparticle/aqueous interface with second harmonic generation

“…The surface plasmons can couple with the incident light and greatly enhance optical signals such as surface enhanced Raman scattering (SERS) [4,5] and surface enhanced fluorescence [6,7], as well as enhanced nonlinear optical processes such as sum-frequency generation (SFG) [8,9] and second harmonic generation (SHG) [10][11][12][13]. Gold nanoparticles, in particular because they are biologically inert, are well suited for many biologically-relevant technologies such as sensing [14,15], labeling [16], and photothermal cancer therapy [17]. However, to maximize the applicability of noble metal nanoparticles to science and technology, more research is required to better understand chemical and physical interactions at the nanoparticle surface.…”

Preparation of Pt Nanoclusters with Different Emission Wavelengths and Their Application in Co2+ Detection

“…[7] Even more important is their lower cytotoxicity and excellent biocompatibility, which makes them relatively safe and nontoxic as fluorescent contrast agents. [8] Until now, highly fluorescent gold and silver nanoclusters (Au NCs and Ag NCs) stabilized by different matrices, such as dendrimers, [9] oligonucleotides, [10] small thiol molecules, [11] proteins, [12] or polymers, [13] have been popular for the bioimaging of living cells. Platinum, another noble metal, has wide catalytic applications, [14] but the fluorescence properties of platinum nanomaterials have not been well investigated.…”