NIR QDs

The cell nucleus is one of the most important organelles as a subcellular drug-delivery target, since modulation of gene replication and expression is effective for treating various diseases. Here, we demonstrate light-triggered nuclear translocation of guests using caged molecular glue (Caged Glue-R) tags, whose multiple guanidinium ion (Gu+ ) pendants are protected by an anionic photocleavable group (butyrate-substituted nitroveratryloxycarbonyl; BA NVOC). Guests tagged with Caged Glue-R are taken up into living cells via endocytosis and remain in endosomes...

The limited penetration depth of photothermal agents (PTAs) active in the NIR-I biowindow and the thermo-resistance caused by heat shock protein (HSP) significantly limit the therapeutic efficiency of the photothermal therapy (PTT). To address the problem, we introduce a strategy of the low-temperature nucleus-targeted PTT in the NIR-II region achieving effective tumor killing by combing of the vanadium carbide quantum dots (V2C QDs) PTA and engineered exosomes (Ex) vector. The small fluorescent V2C QDs with good photothermal effect in the NIR-II region were modified with TAT peptides and packaged into Ex with RGD modification (V2C-TAT@Ex-RGD)...

Fluorescence imaging in the second near-infrared optical window (NIR-II, 900-1700 nm) has become a technique of choice for non-invasive in vivo imaging in recent years. Greater penetration depths with high spatial resolution and low background can be achieved with this NIR-II window, owing to low autofluorescence within this optical range and reduced scattering of long wavelength photons. Here, we present a novel design of confocal laser scanning microscope tailored for imaging in the NIR-II window. We showcase the outstanding penetration depth of our confocal setup with a series of imaging experiments...

Two-dimensional (2D) non-layered nanomaterials have attracted extensive attention for electronic and optoelectronic applications recently due to their distinct properties. In this work, we firstly employed a facile one-step method to synthesize 2D non-layered cadmium sulfide selenide (CdSx Se1-x , x=0.33) nanosheets with highly crystalline structure and then we introduced a generic spin-coating approach to fabricate PbS quantum dots (QDs)/2D CdSx Se1-x nanosheets hybrid nanostructure and demonstrate their potential for high-performance broadband photodetectors...

PbS/CdS core/shell quantum dots (QDs) that emit at the second near-infrared (NIR-II, 1000-1700 nm) window are synthesized. The PbS seed size and CdS shell thicknesses are carefully controlled to produce bright and narrow fluorescence that are suitable for multiplexing. A polymer encapsulation yields polymer-encapsulated NIR-II QDs (PQDs), which provides the QDs with long-term fluorescence stability over a week in biological media. Exploiting the simple bioconjugation capability of PQDs, folic acids are conjugated to PQDs that can efficiently label folate receptor overexpressing cell lines...

An enhanced near-infrared (NIR) FRET biosensing system based on the novel donor-acceptor pair (MnCuInS/ZnS@BSA and urchin-like Au NPs) was developed for the sensitive detection of HER2 protein. In this strategy, MnCuInS/ZnS quantum dots (QDs) were chosen due to their NIR emission, high quantum efficiency, and low toxicity. Amounts of MnCuInS/ZnS QDs were encapsulated in BSA to form MnCuInS/ZnS@BSA nanoparticles, which can easily transfer MnCuInS/ZnS QDs from organic phase into aqueous solution, and the formed nanoparticles were applied as the energy donor which significantly enhanced the fluorescence intensity...

Ag2Se quantum dots (QDs) with near-infrared (NIR) fluorescence have been widely utilized in NIR fluorescence imaging in vivo because of their narrow bulk band gap and excellent biocompatibility. However, most of synthesis methods for Ag2Se QDs were expensive and the reactants were too toxic. In this paper, a new protein-templated biomimetic synthesis approach was proposed for Ag2Se QDs preparation by employing bovine serum albumin (BSA) as template and dispersant. The BSA-templated Ag2Se QDs (Ag2Se@BSA QDs) showed NIR fluorescence with high fluorescence quantum yield (≈21...

Combined chemotherapy and immunotherapy have demonstrated great potential in cancer treatment. However, it is difficult to provide clear information of the pharmacokinetics and pharmacodynamics of chemodrugs and transplanted immune cells in vivo by traditional approaches, resulting in inadequate therapy. Here, a multiplexed intravital imaging strategy by using fluorescence in the second near-infrared window (NIR-II) is first developed to visualize the two events of chemotherapy and immunotherapy in vivo, so that a combinational administration is programed to improve the therapeutical effects against a mouse model of human breast cancer...

Near-infrared (NIR) emitting fluorescent probes are widely used for molecular imaging at the whole-body level. However, NIR- emitting fluorescent probes emitting over 700 nm are not suitable for molecular imaging at the cellular level, because most of the conventional fluorescence microscopes have very low optical sensitivity in the NIR region. Thus, to achieve fluorescence imaging at the cellular and whole-body level using single probes, visible and NIR emitting dual-color fluorescent probes are desirable...

Different from three single precursors producing colloidal ternary quantum dots (QDs), ternary Ag3SbS3 quantum dots (QDs) with efficient near-infrared (NIR) luminescence have been prepared by a new facile in-situ conversion of Ag nanocrystals (NCs) with binary Sb/S organic precursor Sb(C9H19COOS)3 under low temperature. The unprecedented construction evolution from Ag NCs to Ag3SbS3/Ag hetero-structure and final monodisperse Ag3SbS3 QDs have been demonstrated. These novel Ag3SbS3 QDs exhibit efficient NIR emission at ~1263 nm and possess high colloidal stability...

Theranostic platforms integrating imaging diagnostic and therapeutic interventions into a single nanoplatform have attracted considerable attention for cancer-individualized therapies. However, their uncertain stability, complex pharmacokinetics, and intrinsic toxicology of multiple components hinder their practical application in clinical research. In this paper, stable and high-concentration molybdenum carbide quantum dots (Mo₂C QDs) with a diameter of approximately 6 nm and a topographic height of about 1...

Despite the vital role miRNA-27a plays in driving the development and progress of liver cancer, miRNA-based inhibition therapy is hampered due to its undesired degradation and off-target effects. Herein, a multifunctional nanoparticle for noninvasive tracking of targeted delivery of anti-miR-27a oligonucleotides against liver cancer was constructed. Methods: Dual-fluorescent conjugates (QD-HA-PEI) were first fabricated through crosslinking hyaluronic acid (HA), polyethyleneimine (PEI) and near-infrared (NIR) fluorescent quantum dots (QDs) via a facile one-pot approach...

Under near-infrared (NIR) light of 810 nm wavelength for irradiation, a very simple and highly sensitive photoelectrochemical (PEC) biosensing platform has been established using the localized surface plasmon resonance effect of Au nanoparticles (NPs) as signal amplification for the nondestructive analysis of living cells. The water-dispersible Ag2 S quantum dots (QDs) synthesized by a one pot method were employed as photoelectrochemically active species, and they exhibited excellent PEC properties irradiated with NIR light which was chosen due to the obvious absorption and fluorescent emission in the NIR light region...

Boron (B) and phosphorus (P) codoped silicon quantum dots (Si QDs) are dispersible in polar solvents without organic ligands and exhibit photoluminescence (PL) in the first (NIR-I) and second (NIR-II) near infrared (NIR) windows in biological tissues due to the optical transition from the donor to acceptor states. We studied the relationship between the PL wavelength, lifetime and quantum yield (QY) of the colloidal solution and the composition of the starting material for the preparation. We found that the PL lifetime and the QY are primarily determined by the composition, while the PL wavelength is mainly determined by the growth temperature...

Here, we report the synthesis and characterization of CoFe2 O4 doping Ag2 S dendrimer-modified nanoparticles (CoFe2 O4 -Ag2 S DMNs) in Cry1Ab protein detection and imaging. The near-infrared Ag2 S quantum dots were first prepared by using the thermal decomposition method, followed by modification of the water-soluble quantum dots using the method of solvent evaporation and ligand exchange, and finally the fluorescent magnetic bifunctional nanoparticles were obtained by binding with CoFe2 O4 . As-prepared CoFe2 O4 -Ag2 S DMNs were characterized by fluorescence (FL) spectroscopy and transmission electron microscopy (TEM)...

Quantum dots (QDs) of lead chacogenides (e.g. PbS, PbSe and PbTe) are attractive near-infrared (NIR) active materials that show great potential in a wide range of applications such as photovoltaics (PV), optoelectronics, sensors, bio-electronics and many others. The successful utilization of these functional materials requires deep understanding of their synthesis, properties and material modification process. The surface ligand plays an essential role in the production of QDs, post-synthesis modification and their integration to practical applications...

Ternary alloyed CdSe x Te1- x colloidal QDs trap-passivated by iodide-based ligands (TBAI) are developed as building blocks for UV-NIR photodetectors. Both the few surface traps and high loading of QDs are obtained by in situ ligand exchange with TBAI. The device is sensitive to a broad wavelength range covering the UV-NIR region (300-850 nm), showing an excellent photoresponsivity of 53 mA/W, a fast response time of ≪0.02s, and remarkably high detectivity values of 8 × 1013 Jones at 450 nm and 1 × 1013 Jones at 800 nm without an external bias voltage...

Near-infrared (NIR) fluorescent quantum dots (QDs) are ideal platforms to fabricate multifunctional contrast agents for multimodal imaging. Herein, second near-infrared window fluorescent (NIR-II) Ag2Se QDs were coupled with gadopentetate dimeglumine injection (Gd-DTPA) for dual-modality T1-weighted magnetic resonance (MR) imaging and fluorescence imaging. In vitro experiments suggested that the prepared Ag2Se-Gd QDs exhibit low cytotoxicity, remarkable T1-weighted MR imaging, and fluorescence imaging contrast properties...

Semiconductor quantum dots (QDs) are promising luminescent materials for use in lighting, display and bio-imaging, and the color tuning is a necessity for such applications. In this work, we report tunable colors and deep-red or near infrared (NIR) emissions in Cu-In-S and Cu-In-S/ZnS QDs by incorporating Sn. These QDs (with a size of 5 nm) with varying Sn concentrations and/or Cu/In ratios were synthesized by a non-injection method, and characterized by a variety of analytical techniques (i.e., XRD, TEM, XPS, absorption, photoluminescence, decay time, etc...

TiO2 nanotube arrays (TiO2 NTAs) decorated with molybdenum disulfide quantum dots (MoS2 QDs) were synthesized by a facile electrodeposition method and used as a composite photocatalyst. MoS2 QDs/TiO2 NTAs showed enhanced photocatalytic activity compared with pristine TiO2 NTAs for solar light-promoted H2 evolution without adding any sacrificial agents or cocatalysts. The photocatalytic activity was influenced by the amount of MoS2 QDs coated on TiO2 NTAs. The optimal composition showed excellent photocatalytic activity, achieving H2 evolution rates of 31...