Our understanding on the microstructure and the organic passivation with surface ligands is inadequate to influence the design of these nanoparticles for near infrared light emission. The mechanistic insight into the origin of fluorescence from carbon nanoparticles is unclear. These methods lack the suitability for commercial production and often suffer low yield, insolubility of as-synthesized particles, complex purification, and weak photo luminescence. A wide range of synthetic approaches have been pursued to produce carbon nanoparticles including arc discharge, laser ablation, electrochemical oxidation, candle burning and combustion of natural gas burners. Furthermore, their inherent chemical inertness and biocompatibility make them more advantageous over conventional cadmium based quantum dots. Luminescent carbon nanoparticles have emerged as a promising approach showing high potential in biological labeling, bio-imaging and various optoelectronic device applications. However, the optical properties of gold are highly dependent on expensive and complicated surface chemistry and their clinical use is discouraged by the unpredictable high cost. Few-atom gold nanoclusters have sizes comparable to the Fermi wavelength, resulting in molecule-like behavior including discreet electronic states and size-dependent fluorescence. Fluorescent emission from small gold nanoclusters in solution has been disclosed. However their relatively bigger size (~90 nm) puts a question over their future clinical translation. Aggregation-induced emission organic nanoparticles, such as Ln 3+ doped HAp nanoparticles and polydopamine nanoparticles have been developed for cell imaging. Unfavorably, the synthesis of quantum dots involves harsh conditions and toxic precursors, which make them less prone to surface passivation and may impart severe long term toxicity. Semiconductor quantum dots exhibit excellent photophysical properties, which include size-tunable narrow emissions, large Stokes shifts and minimal photo bleaching. Additionally, small Stokes shifts of organic fluorochrome can cause self-quenching and measurement error by excitation and scattered light. Large fluorescent tags also can perturb the labeled biomolecules, causing artificial movement within cells and changed protein interactions. Organic fluorochromes are easily photo-bleached during the time scale of observation, leading to reduced sensitivity and decreased tracking time of the targets. Unfortunately, the performance and sensitivity of these laser-induced fluorescence techniques are limited by the long-standing barrier of fluorescent probes. Introductionįluorescence sensing and imaging techniques use exogenous (fluorescent probes) or endogenous (reporter genes) agents excited at particular wavelengths for in vitro detection of molecules and in vivo bio-imaging. Keywords: Carbon nanoparticle, hyperbranched polymer, near infrared imaging, contrast agent, surface passivation. The exceptionally rapid lymphatic transport of these particles suggests that such an approach may offer greater convenience and reduced procedural expense, as well as improved surgical advantage as the patient is positioned on the table for easier resection. Preliminary in vivo experiment showed high contrast enhancement in auxiliary lymphnode in a mouse model. The particles showed negligible loss of cell viability in presence of endothelial cells in vitro. Interestingly, as passivating agent becomes more extensively branched (pseudo generation 2 to 4), the average radiant efficiency amplifies considerably as a direct result of the increasing surface area available for light passivation. A dramatic increase in near infrared emission was achieved compared to a linear polymer (PEG) coated carbon nanoparticles. ![]() The fluorescence properties of these particles were significantly enhanced by utilizing hyberbranched polymer for surface passivation. The naked carbon particles (<20 nm) were derived from commercial food grade honey. File import instruction AbstractĪ superior and commercially exploitable 'green synthesis' of optically active carbon nanoparticle (OCN) is revealed in this work. Select the file that you have just downloaded and select import option Reference Manager (RIS). Surface Passivation of Carbon Nanoparticles with Branched Macromolecules Influences Near Infrared Bioimaging. Wu L, Luderer M, Yang X, Swain C, Zhang H, Nelson K, Stacy AJ, Shen B, Lanza GM, Pan D.
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