Visualization of melanoma tumor with lectin-conjugated rare-earth doped fluoride nanocrystals

Aim To develop specific fluorescent markers for melanoma tumor visualization, which would provide high selectivity and reversible binding pattern, by the use of carbohydrate- recognizing proteins, lectins, combined with the physical ability for imaging deep in the living tissues by utilizing red and near infrared fluorescent properties of specific rare-earth doped nanocrystals (NC). Methods B10F16 melanoma cells were inoculated to C57BL/6 mice for inducing experimental melanoma tumor. Tumors were removed and analyzed by lectin-histochemistry using LABA, PFA, PNA, HPA, SNA, GNA, and NPL lectins and stained with hematoxylin and eosin. NPL lectin was conjugated to fluorescent NaGdF4:Eu3+-COOH nanoparticles (5 nm) via zero length cross-linking reaction, and the conjugates were purified from unbound substances and then used for further visualization of histological samples. Fluorescent microscopy was used to visualize NPL-NaGdF4:Eu3+ with the fluorescent emission at 600-720 nm range. Results NPL lectin selectively recognized regions of undifferentiated melanoblasts surrounding neoangiogenic foci inside melanoma tumor, PNA lectin recognized differentiated melanoblasts, and LCA and WGA were bound to tumor stroma regions. NPL-NaGdF4:Eu3+ conjugated NC were efficiently detecting newly formed regions of melanoma tumor, confirmed by fluorescent microscopy in visible and near infrared mode. These conjugates possessed high photostability and were compatible with convenient xylenebased mounting systems and preserved intensive fluorescent signal at samples storage for at least 6 months. Conclusion NPL lectin-NaGdF4:Eu3+ conjugated NC permitted distinct identification of contours of the melanoma tissue on histological sections using red excitation at 590- 610 nm and near infrared emission of 700-720 nm. These data are of potential practical significance for development of glycans-conjugated nanoparticles to be used for in vivo visualization of melanoma tumor

CdS Dots, Rods and Platelets—How to Obtain Predefined Shapes in a One-Pot Synthesis of Nanoparticles

In recent years, numerous protocols for nanoplatelet synthesis have been developed. Here, we present a facile, one-pot method for controlling cadmium sulfide (CdS) nanoparticles’ shape that allows for obtaining zero-dimensional, one-dimensional, or two-dimensional structures. The proposed synthesis protocol is a simple heating-up approach and does not involve any inconvenient steps such as injection and/or pouring the precursors at elevated temperatures. Because of this, the synthesis protocol is highly repeatable. A gradual increase in the zinc acetate concentration causes the particles’ shape to undergo a transition from isotropic quantum dots through rods to highly anisotropic nanoplatelets. We identified conditions at which synthesized platelets were purely five monolayers thick. All samples acquired during different stages of the reaction were characterized via optical spectroscopy, which allowed for the identification of the presence of high-temperature, magic-size clusters prior to the platelets’ formation

CdS Dots, Rods and Platelets—How to Obtain Predefined Shapes in a One-Pot Synthesis of Nanoparticles

In recent years, numerous protocols for nanoplatelet synthesis have been developed. Here, we present a facile, one-pot method for controlling cadmium sulfide (CdS) nanoparticles’ shape that allows for obtaining zero-dimensional, one-dimensional, or two-dimensional structures. The proposed synthesis protocol is a simple heating-up approach and does not involve any inconvenient steps such as injection and/or pouring the precursors at elevated temperatures. Because of this, the synthesis protocol is highly repeatable. A gradual increase in the zinc acetate concentration causes the particles’ shape to undergo a transition from isotropic quantum dots through rods to highly anisotropic nanoplatelets. We identified conditions at which synthesized platelets were purely five monolayers thick. All samples acquired during different stages of the reaction were characterized via optical spectroscopy, which allowed for the identification of the presence of high-temperature, magic-size clusters prior to the platelets’ formation

Facile synthesis of phosphine free ultra-small PbSe nanocrystals and their light harvesting studies in ETA solar cells

Ultra-small PbSe nanocrystals (NCs) were synthesized via a ‘one-pot’ approach in olive oil as the reaction medium and capping agent.</p

CdS Nanoplates Modification as a Platform for Synthesis of Blue-Emitting Nanoparticles

In this paper, the study of surface modification of two-dimensional (2D), non-luminescent CdS nanoplates (NPLs) by thiol-containing ligands is presented. We show that a process of twophase transfers with appropriate ligand exchange transforms non-luminescent NPLs into spherical CdS nanoparticles (NPs) exhibiting a blue photoluminescence with exceptionally high quantum yield ~90%. In the process, transfer from inorganic solvent to water is performed, with appropriately selected ligand molecules and pH values (forward phase transfer), which produces NPs with modified size and shape. Then, in reverse phase transfer, NPs are transferred back to toluene due to surface modification by combined Cd (OL)2 and Cd (Ac)2. As a result, spherical NPs are formed (average diameter between 4 and 6 nm) with PL QY as high as 90%. This is unique for core only CdS NPs without inorganic shell

Special Role for Zinc Stearate and Octadecene in the Synthesis of Luminescent ZnSe Nanocrystals

Special Role for Zinc Stearate and Octadecene in the Synthesis of Luminescent ZnSe Nanocrystal

Controlled synthesis of tuned bandgap nanodimensional alloys of PbS xSe1-x

Truly alloyed PbSxSe1−x (x = 0−1) nanocrystals (∼5 nm in size) have been prepared, and their resulting optical properties are red-shifted systematically as the sulfur content of the materials increases. Their optical properties are discussed using a modified Vegard’s approach and the bowing parameter for these nanoalloys is reported for the first time. The alloyed structure of the nanocrystals is supported by the energy-filtered transmission electron microscope images of the samples, which show a homogeneous distribution of sulfur and selenium within the nanocrystals. X-ray photoelectron spectroscopy studies on ligand-exchanged nanocrystals confirmed the expected stoichiometry and various oxidized species