Fluorescent Probes For Cell Imaging Research Articles

Waste frying oil as a precursor for one-step synthesis of sulfur-doped carbon dots with pH-sensitive photoluminescence

Proper disposal of waste frying oil (WFO) is an important waste-management concern. In this paper, we develop a facile method to reuse WFO for one-step synthesis of sulfur-doped carbon dots (S-C-dots) with the assistance of concentrated sulfuric acid. The as-synthesized S-C-dots are uniform in size and show partial disordered graphite-like structure. Different from the doping-free or nitrogen-doped carbon dots, the S-C-dots perform a strong ultraviolet emission at 378nm due to successful sulfur-doping. Noticeably, the S-C-dots exhibit a distinct pH-sensitive feature and the intensity of photoluminescence increases linearly in the pH range from 3 to 9. Furthermore, possessing fascinating optical properties, high photostability, and low cytotoxicity, the S-C-dots have served as fluorescent probes for cell imaging.

Dual functionality of conjugated polymer nanoparticles as an anticancer drug carrier and a fluorescent probe for cell imaging

Multifunctional nanoparticles based on a green emitting, hydrophobic conjugated polymer, poly[(9,9-bis{propeny}fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1,3}-thiodiazole)] (PPFBT), that acts both as a fluorescent reporter and a matrix to accommodate an anti-cancer compound, camptothecin (CPT), were prepared, characterized and their potential as a fluorescent probe for cell imaging and as a drug delivery vehicle were evaluated via in vitro cell assays. The cell viability of human hepatocellular carcinoma cell line (Huh7) was investigated in the absence and presence of CPT with sulforhodamine B (SRB) and real-time cell electronic sensing (RT-CES) cytotoxicity assays.

Facile synthesis of water-soluble and biocompatible fluorescent nitrogen-doped carbon dots for cell imaging

A simple, facile and green hydrothermal method was developed in the synthesis of water-soluble nitrogen-doped carbon dots (N-CDs) from streptomycin. The as-prepared N-CDs displayed bright blue fluorescence under the irradiation of UV light, together with a high quantum yield of 7.6% and good biocompatibility as demonstrated by the cell viability assay. Thus, the N-CDs can be used as fluorescent probes for cell imaging, which have potential applications in bioimaging and related fields. This strategy opens a new way for the preparation of fluorescent carbon nanomaterials using small molecules as carbon sources.

Development of multicolor carbon nanoparticles for cell imaging

Multicolor carbon nanoparticles (CNPs) were prepared, characterized and developed as fluorescent probes for cell imaging. The fluorescent CNPs were prepared with a facile hydrothermal oxidation route by using linear polysaccharide cellulose and cyclic oligosaccharide cyclodextrin as carbon sources. The characterizations by transmission electron microscopy show that the prepared cellulose-CNPs and cyclodextrin-CNPs are spherical, well-dispersed in water with average diameters of 100nm and 76nm, respectively. Under the excitation of UV light, the CNPs are strongly luminescent with an excitation-dependent emission behavior and bathochromic emission properties. The fluorometric methods show that the cellulose-CNPs and cyclodextrin-CNPs are strongly fluorescent with fluorescence quantum yield of 7.47% and 4.49%, respectively. The multicolor CNPs have excellent photostability toward photobleaching. Strong near-infrared fluorescence of the carbon nanoparticles was observed with a 632.8nm excitation wavelength laser. The oxidative metal ions like Hg(II), Cu(II) and Fe(III) show an quench effect on the fluorescence intensity of the CNPs. The multicolor CNPs were successfully used as fluorescent probes for mouse melanoma cells imaging. The results indicate that the multicolor CNPs derived from cellulose and cyclodextrin may have a great potential for the applications in bioimaging.

An Al3+ induced green luminescent fluorescent probe for cell imaging and naked eye detection

A novel pyrimidine based Al3+ selective fluorescent probe (L) has been synthesised by a facile one step coupling of 4,5-diamino pyrimidine with 2-hydroxy naphthaldehyde. L has been obtained in pure crystalline form without any column chromatographic purification. Upon binding Al3+, the single emission band of L undergoes red shift from 470 nm to dual emission peaks viz. 505 nm and 538 nm with appearance of a very intense green luminescence. L could detect as low as 2.9 × 10−7 M Al3+ with a binding constant value of 5.4 × 104 M−1. Al3+ contaminated cells became green in the presence of L making it suitable for intracellular Al3+ detection.

Facile One‐Pot Synthesis of Luminescent, Water‐Soluble, and Biocompatible Glutathione‐Coated CdTe Nanocrystals

A shining example: We report a facile strategy to synthesize highly luminescent, water-soluble, and biocompatible CdTe nanocrystals by using the biomolecule glutathione as a stabilizer. The highest quantum yield obtained was above 60 % and their size-dependent emission ranged from 480 to 650 nm. The nanocrystals could be coupled with antibodies to prepare fluorescent probes for cell imaging (see figure).

Highly luminescent CdTe quantum dots prepared in aqueous phase as an alternative fluorescent probe for cell imaging

In this paper, our main aim is to explore the feasibility for application of luminescent CdTe quantum dots prepared in aqueous phase to live and fixed cell imaging. The highly luminescent CdTe quantum dots (QDs) were first prepared in aqueous phase using 3-mercaptopropionic acid (MPA) as a ligand, and then were covalently coupled to a plant lectin (UEA-1) and antibody anti-von Willebrand factors (anti-vWF) as fluorescent probes. Two probes QD-UEA-1 and QD-anti-vWF) were able to specifically bind the corresponding cell membrane receptor and cytoplasm immunogen, respectively. The good cell images were obtained in live cells and fixed cells using laser confocal scanning microscopy. Our preliminary results illustrated that CdTe QDs prepared in water phase were highly luminescent, water-soluble, stable, and easily conjugated with biomolecules since their surface were coated with MPA containing free carboxyl group. We predict that QDs prepared in water phase will probably become an attractive alternative probe in cellular imaging and bio-labeling.