Application Of Quantum Dots Research Articles

Ligand‐Free CsPbBr3 Perovskite Quantum Dots in Silica‐Aerogel Composites with Enhanced Stability for w‐LED and Display by Substituting Pb2+ with Pr3+ or Gd3+ Ions

AbstractColloidal all‐inorganic lead halide perovskite nanocrystals (LHP NCs) feature with tunable high‐efficiency photoluminescence from blue to red for optoelectronic applications but suffer from instability under water moisture, UV light illumination, high‐temperature shock, as well as oxygen erosion. Previous work to improve LHP NCs stability was mainly focused on either glass bulk sealed LHP quantum dots (QDs) with low quantum efficiency, or mesoporous silica matrixes confined LHP QDs with organic ligands still existing. Here, a facile, noncolloidal, ligand‐free LHP QDs growth with physical confinement is proposed by integrating the growth of perovskite QDs with the fabrication process of hydrophobic silica‐aerogel powders (SAPs). As a result, the as‐synthesized mono‐ and mixed‐cesium‐lead‐halide QDs @ SAPs composites show tunable photoluminescence from purple to deep red. Besides, the Pr3+ ions doped CsPbBr3 QDs @ SAPs composites exhibit moderate quantum efficiency, excellent stability under UV illumination, water moisture as well as temperature variation. Furthermore, performances of white LED device encapsulated Pr3+ doped composite with blue GaN chip and commercial red (Sr, Ca)AlSiN3:Eu2+ phosphor are evaluated. This work demonstrates a facile and general strategy for synthesizing high‐stable all‐inorganic cesium‐lead‐halide QDs for applications in white LED and display devices.

Long-Term Fluorescence Behavior of CdSe/ZnS Quantum Dots on Various Planar Chromatographic Stationary Phases.

Nanoparticles, particularly quantum dots (QDs), are commonly used for the sensitive detection of various objects. A number of target molecules may be determined using QDs sensing systems. Depending on their chemical nature, physicochemical properties, and spatial arrangement, QDs can selectively interact with given molecules of interest. This can be performed in complex systems, including microorganisms or tissues. Efficient fluorescence enables low exposure of QDs and high sensitivity for detection. One disadvantage of quantum dots fluorophores is fluorescence decay. However, for given applications, this property may be an advantage, e.g., for highly sensitive detection based on correlation images in the time domain. This experimental work deals with the measurement of fluorescence decay of Lumidot TMCdSe/ZnS (530 nm) quantum dots. These nanoparticles were transferred to the surface of various planar chromatographic stationary phases. Fluorescence of formed spots was recorded at room temperature over a long period of time, namely 15.7824 × 105 min (three years). The resulting signal profiles in the time domain were analyzed using classical approach (luminescence model comparison involving different mathematical models).Moreover, fluorescence behavior on different TLC/HPTLC supports was investigated using multivariate statistics (principal component analysis, PCA). Eight planar chromatographic stationary phases were investigated, including cellulose, octadecylsilane, polyamide, silica gel and aluminium oxide in different forms (TLC and HPTLC types). The presented research revealed significantly different and non-linear long-term QDs behavior on these solids. Two different fluorescence signal trajectories were recorded, including typical signal decay after QDs application to the plates and long-term intensity increase. This was particularly visible for given planar chromatographic adsorbents, e.g., cellulose or octadecylsilane. To the author’s knowledge, these findings were not reported before using the stationary chromatographic phases, and enable the design of future experiments toward sensing of low molecular mass chemicals using, e.g., advanced quantification approaches. This may include signal processing computations based on correlation images in the time domain. Additionally, the reported preliminary data indicates that the investigated nanoparticles can be applied as efficient and selective fluorophores. This was demonstrated on micro-TLC plates where separated bioactive organic substances quenching from cyanobacteria extracts were sensitively detected. The described detection protocol can be directly applied for different planar chromatographic systems, including paper-based microfluidic devices, planar electrophoresis and/or miniaturized microfluidic chip devices.

Novel model for predicting the future volume of research articles on applications of Quantum Dots

The paper aims to briefly introduce to the topic of quantum heterostructures taking Quantum Dots (QD) as the topic of interest. It reviews different mathematical models explaining the behaviour of QD, and it proposes a novel method to predict the future article volumes on the topic of applications of QD. The paper also reviews the use of QD in quantum computing. The paper opted for a numerical approach to predict future article volumes. Firstly, bibliometric data for the past 40 years is collected and then by assuming a relationship between relevant variables, a governing equation is developed which is then solved using the Finite Difference Method (FDM). The paper provides insights into how a prediction model can be developed without using tons of metrics. It also suggests that a prediction model can be developed using only the past behaviour of the concerned dataset. Due to the chosen research approach, the effectiveness of the model may be less. Therefore, researchers are encouraged to test the proposed method further. The paper includes the practical implications of an easily analysed and executable model. The paper also shows that the model proposed can not only be used to predict future article volumes but also to predict datasets that exhibit a quasi-linear nature. This paper fulfils the need for a new, easier prediction method.

Assessing the Environmental Effects Related to Quantum Dot Structure, Function, Synthesis and Exposure.

Quantum dots (QDs) are engineered semiconductor nanocrystals with unique fluorescent, quantum confinement, and quantum yield properties, making them valuable in a range of commercial and consumer imaging, display, and lighting technologies. Production and usage of QDs are increasing, which increases the probability of these nanoparticles entering the environment at various phases of their life cycle. This review discusses the major types and applications of QDs, their potential environmental exposures, fates, and adverse effects on organisms. For most applications, release to the environment is mainly expected to occur during QD synthesis and end-product manufacturing since encapsulation of QDs in these devices prevents release during normal use or landfilling. In natural waters, the fate of QDs is controlled by water chemistry, light intensity, and the physicochemical properties of QDs. Research on the adverse effects of QDs primarily focuses on sublethal endpoints rather than acute toxicity, and the differences in toxicity between pristine and weathered nanoparticles are highlighted. A proposed oxidative stress adverse outcome pathway framework demonstrates the similarities among metallic and carbon-based QDs that induce reactive oxygen species formation leading to DNA damage, reduced growth, and impaired reproduction in several organisms. To accurately evaluate environmental risk, this review identifies critical data gaps in QD exposure and ecological effects, and provides recommendations for future research. Future QD regulation should emphasize exposure and sublethal effects of metal ions released as the nanoparticles weather under environmental conditions. To date, human exposure to QDs from the environment and resulting adverse effects has not been reported.

Intracellular reactive oxygen species trigger mitochondrial dysfunction and apoptosis in cadmium telluride quantum dots-induced liver damage

Quantum dots (QDs), also known as semiconductor QDs, have specific photoelectricproperties which find application in bioimaging, solar cells, and light-emitting diodes (LEDs). However, the application of QDs is often limited by issues related to health risks and potential toxicity. The purpose of this study was to provide evidence regarding the safety of cadmium telluride (CdTe) QDs by exploring the detailed mechanisms involved in its hepatotoxicity. This study showed that CdTe QDs can increase reactive oxygen species (ROS) in hepatocytes after being taken up by hepatocytes, which triggers a significant mitochondrial-dependent apoptotic pathway, leading to hepatocyte apoptosis. CdTe QDs-induce mitochondrial cristae abnormality, adenosine triphosphate (ATP) depletion, and mitochondrial membrane potential (MMP) depolarization. Meanwhile, CdTe QDs can change the morphology, function, and quantity of mitochondria by reducing fission and intimal fusion. Importantly, inhibition of ROS not only protects hepatocyte viability but can also interfere with apoptosis and activation of mitochondrial dysfunction. Similarly, the exposure of CdTe QDs in Institute of Cancer Research (ICR) mice showed that CdTe QDs caused oxidative damage and apoptosis in liver tissue. NAC could effectively remove excess ROS could reduce the level of oxidative stress and significantly alleviate CdTe QDs-induced hepatotoxicity in vivo. CdTe QDs-induced hepatotoxicity may originate from the generation of intracellular ROS, leading to mitochondrial dysfunction and apoptosis, which was potentially regulated by mitochondrial dynamics. This study revealed the nanobiological effects of CdTe QDs and the intricate mechanisms involved in its toxicity at the tissue, cell, and subcellular levels and provides information for narrowing the gap between in vitro and in vivo animal studies and a safety assessment of QDs.

Indium arsenide quantum dots: an alternative to lead-based infrared emitting nanomaterials.

Colloidal quantum dots (QDs) emitting in the infrared (IR) are promising building blocks for numerous photonic, optoelectronic and biomedical applications owing to their low-cost solution-processability and tunable emission. Among them, lead- and mercury-based QDs are currently the most developed materials. Yet, due to toxicity issues, the scientific community is focusing on safer alternatives. In this regard, indium arsenide (InAs) QDs are one of the best candidates as they can absorb and emit light in the whole near infrared spectral range and they are RoHS-compliant, with recent trends suggesting that there is a renewed interest in this class of materials. This review focuses on colloidal InAs QDs and aims to provide an up-to-date overview spanning from their synthesis and surface chemistry to post-synthesis modifications. We provide a comprehensive overview from initial synthetic methods to the most recent developments on the ability to control the size, size distribution, electronic properties and carrier dynamics. Then, we describe doping and alloying strategies applied to InAs QDs as well as InAs based heterostructures. Furthermore, we present the state-of-the-art applications of InAs QDs, with a particular focus on bioimaging and field effect transistors. Finally, we discuss open challenges and future perspectives.

Confocal laser scanning microscopy study of intercellular events in filopodia using 3-mercaptopropoinc acid capped CdSe/ZnS quantum dots

Physico-chemical mobility of cells in three dimensions is dependent on the development of filipodia, which is the fundamental instinct for survival and other cellular functions in live cells. Specifically, our present research paper describes the synthesis of 3-Mercaptopropoinc acid (MPA) capped CdSe/ZnS quantum dots (QDs), which are biocompatible and utilized for cellular bioimaging applications. Using the pancreatic cell lines BXCP3 cells, we successfully demonstrated the applicability of MPA-capped QDs for intercellular filopodia imaging. Employing these QDs, we examined the dynamics of filopodia formation in real-time along the Z-axis by using confocal laser microscopy.

Influence of Noise–Anharmonicity Interplay on a Few Physical Properties of Quantum Dots

Herein, a meticulous inspection of the tuning of a few important physical properties of quantum dots (QDs), arising out of the subtle interplay between Gaussian white noise (GWN) and anharmonicity, is performed. The physical properties considered are dipole moment, polarizability, Stark shift, magnetic susceptibility, binding energy, interband emission energy, and time‐average excitation rate. The pathway of the introduction of noise (additive/multiplicative) to the QD system, coupled with the symmetry (odd/even) of the anharmonic potential present in the system produces delicate and diverse features in the aforementioned physical properties. These physical attributes consist of monotonic growth, monotonic decline, maximization, minimization, and saturation in these physical properties modulated by different extents of the interplay between the noise mode and the symmetry of the anharmonicity. The study holds relevance in view of potential technological applications of QDs under the simultaneous influence of anharmonic potential and noise.

All-optical fluorescence blinking control in quantum dots with ultrafast mid-infrared pulses.

Photoluminescence intermittency is a ubiquitous phenomenon, reducing the temporal emission intensity stability of single colloidal quantum dots (QDs) and the emission quantum yield of their ensembles. Despite efforts to achieve blinking reduction by chemical engineering of the QD architecture and its environment, blinking still poses barriers to the application of QDs, particularly in single-particle tracking in biology or in single-photon sources. Here, we demonstrate a deterministic all-optical suppression of QD blinking using a compound technique of visible and mid-infrared excitation. We show that moderate-field ultrafast mid-infrared pulses (5.5 μm, 150 fs) can switch the emission from a charged, low quantum yield grey trion state to the bright exciton state in CdSe/CdS core-shell QDs, resulting in a significant reduction of the QD intensity flicker. Quantum-tunnelling simulations suggest that the mid-infrared fields remove the excess charge from trions with reduced emission quantum yield to restore higher brightness exciton emission. Our approach can be integrated with existing single-particle tracking or super-resolution microscopy techniques without any modification to the sample and translates to other emitters presenting charging-induced photoluminescence intermittencies, such as single-photon emissive defects in diamond and two-dimensional materials.

Synthesis, Properties and Bioimaging Applications of Silver-Based Quantum Dots.

Ag-based quantum dots (QDs) are semiconductor nanomaterials with exclusive electrooptical properties ideally adaptable for various biotechnological, chemical, and medical applications. Silver-based semiconductor nanocrystals have developed rapidly over the past decades. They have become a promising luminescent functional material for in vivo and in vitro fluorescent studies due to their ability to emit at the near-infrared (NIR) wavelength. In this review, we discuss the basic features of Ag-based QDs, the current status of classic (chemical) and novel methods (“green” synthesis) used to produce these QDs. Additionally, the advantages of using such organisms as bacteria, actinomycetes, fungi, algae, and plants for silver-based QDs biosynthesis have been discussed. The application of silver-based QDs as fluorophores for bioimaging application due to their fluorescence intensity, high quantum yield, fluorescent stability, and resistance to photobleaching has also been reviewed.

Influence of zinc doping on the molecular biocompatibility of cadmium-based quantum dots: Insights from the interaction with trypsin

Doping quantum dots (QDs) with extra element presents a promising future for their applications in the fields of environmental monitoring, commercial products and biomedical sciences. However, it remains unknown for the influence of doping on the molecular biocompatibility of QDs and the underlying mechanisms of the interaction between doped-QDs and protein molecules. Using the “one-pot” method, we synthesized N-acetyl-l-cysteine capped CdTe: Zn2+ QDs with higher fluorescence quantum yield, improved stability and better molecular biocompatibility compared with undoped CdTe QDs. Using digestive enzyme trypsin (TRY) as the protein model, the interactions of undoped QDs and Zn-doped QDs with TRY as well as the underlying mechanisms were investigated using multi-spectroscopy, isothermal titration calorimetry and dialysis techniques. Van der Waals forces and hydrogen bonds are the major driving forces in the interaction of both QDs with TRY, which leading to the loosening of protein skeleton and tertiary structural changes. Compared with undoped QDs, Zn-doped QDs bind less amount of TRY with a higher affinity and then release higher amount of Cd. Zn-doped QDs have a less stimulating impact on TRY activity by decreasing TRY binding and reducing Cd binding to TRY. Taken all together, Zn-doped QDs offer a safer alternative for the applications of QDs by reducing unwanted interactions with proteins and improving biocompatibility at the molecular level.

Pixelated Microsized Quantum Dot Arrays Using Surface-Tension-Induced Flow.

Quantum dots (QDs) are semiconducting nanoparticles that exhibit unique fluorescent characteristics when excited by an ultraviolet light source. Owing to their highly saturated emissions, display panels using QDs as pixels have been presented. However, the complications of the nanofabrication procedure limit the industrial application of QDs. This study suggests a method to arrange high-aspect-ratio QD pixels by inducing both Laplace-pressure-driven capillary flow and thermally driven Marangoni flow. The evaporation of colloidal QDs induces a capillary flow that drives the QDs toward the inner tips of V-shaped structures. Additionally, the Marangoni flow arranges the gathered QDs at the tip; thus, they could form a high dune, overcoming the limitations of the existing capillary assembly method using evaporation. Using these phenomena, clover-shaped (assembly of V-shaped edges) templates were made to gather numerous QDs, and the clover with a 30° angle afforded the highest brightness among all the angle structures. Finally, by demonstrating a 100-cm2-sized QD microarray with high uniformity (98.6%), our method shows the feasibility of large-area fabrication, which has extensive application in manufacturing QD displays, anti-counterfeiting labels, and other QD-based optical devices.

Room-Temperature Direct Synthesis of PbSe Quantum Dot Inks for High-Detectivity Near-Infrared Photodetectors.

A PbSe colloidal quantum dot (QD) is typically a solution-processed semiconductor for near-infrared (NIR) optoelectronic applications. However, the wide application of PbSe QDs has been restricted due to their instability, which requires tedious synthesis and complicated treatments before being applied in devices. Here, we demonstrate efficient NIR photodetectors based on the room-temperature, direct synthesis of semiconducting PbSe QD inks. The in-situ passivation and the avoidance of ligand exchange endow PbSe QD photodetectors with high efficiency and low cost. By further constructing the PbSe QDs/ZnO heterostructure, the photodetectors exhibit the NIR responsivity up to 970 mA/W and a detectivity of 1.86 × 1011 Jones at 808 nm. The obtained performance is comparable to that of the state-of-the-art PbSe QD photodetectors using a complex ligand exchange strategy. Our work may pave a new way for fabricating efficient and low-cost colloidal QD photodetectors.

Water-Soluble High-Quality Ag2Te Quantum Dots Prepared by Mutual Adaptation of Synthesis and Surface Modification for In Vivo Imaging.

Near-infrared (NIR) in vivo fluorescence imaging has exhibited the distinct advantage of high optical resolution at deeper penetration into biological tissues. Ag2Te quantum dots (QDs), with a relatively narrow band gap, show great promise for fluorescence emission at long wavelengths in the second near-infrared (NIR-II) window for bioimaging. However, existing Ag2Te QDs have severely hindered the application of in vivo bioimaging due to their poor fluorescence brightness and stability, so it is important to prepare Ag2Te QDs with high quantum yield and stability as well as high biocompatibility in the NIR-II window. Herein, we designed an integrated method for the preparation of water-soluble Ag2Te QDs by mutual adaptation of QD synthesis and surface modification. We first synthesized high-quality Ag2Te QDs with different NIR-II emission wavelengths and the photoluminescence quantum yields (PLQYs) up to 6.51% by rapidly injecting the TBP-Te precursor into a hot solvent to form a highly fluorescent Ag2Te core. Then water-dispersible Ag2Te QDs were obtained by direct exchange of the hydrophobic Ag2Te QD surface ligands with thiol ligands. The PLQY of the water-soluble Ag2Te QDs obtained by this method can still be maintained at 4.94%. With these highly bright and stable Ag2Te QDs, the abdominal vessels, hindlimb arterial vessels, venous vessels, sacral lymph nodes, and tumor vessels were visualized non-invasively in vivo in the NIR-II window in mice. The results demonstrate that the integrated strategy of QD synthesis and modification provides valuable technical support for further in-depth applications of Ag2Te QDs.

Structural Dynamics and Electronic Properties of Semiconductor Quantum Dots: Computational Insights

Semiconductor quantum dots (QDs) exhibit exciting photophysical properties for a wide variety of applications in the field of energy conversion, lighting, and more recently quantum communication. The photophysics underpinning these applications at ambient conditions strongly depends on atomistic details of their dynamic surface. Neutral organic ligands used in surface passivation play a critical role in determining the structural and optoelectronic properties of these QDs. Small sizes and irregular atomic arrangements make these QD surface–ligand interfaces challenging to explore at the atomistic level. Here, we combine several computational simulation techniques to study thermally induced geometrical fluctuations in stable cadmium selenide (CdSe) QDs with and without ligand passivation. We find that structural fluctuations of surface atoms significantly depend on passivating molecules. The bulky and strongly binding ligands such as phosphine oxides induce a higher extent of interfacial dynamics. Though these stoichiometric QDs do not possess any permanent in-gap states, significant thermal distortion of QD–ligand interfaces can induce fluctuating defectlike states near band edges. Such vibronic dynamics in these QDs also modifies band-edge state positions on sub-picosecond timescale, impacting their functional properties. Our results further suggest that primary amine ligands are optimal choices for QD passivation. These insights may be helpful to make design principles for screening and optimizing passivating ligands best suited for various QD applications, such as for quantum communication technologies.

Synthesis and Application of Silica-Coated Quantum Dots in Biomedicine.

Quantum dots (QDs) are semiconductor nanoparticles with outstanding optoelectronic properties. More specifically, QDs are highly bright and exhibit wide absorption spectra, narrow light bands, and excellent photovoltaic stability, which make them useful in bioscience and medicine, particularly for sensing, optical imaging, cell separation, and diagnosis. In general, QDs are stabilized using a hydrophobic ligand during synthesis, and thus their hydrophobic surfaces must undergo hydrophilic modification if the QDs are to be used in bioapplications. Silica-coating is one of the most effective methods for overcoming the disadvantages of QDs, owing to silica’s physicochemical stability, nontoxicity, and excellent bioavailability. This review highlights recent progress in the design, preparation, and application of silica-coated QDs and presents an overview of the major challenges and prospects of their application.

PHARMACEUTICAL AND BIOPHARMACEUTICAL ASPECTS OF QUANTUM DOTS-AN OVERVIEW

In the twenty-first century, nanotechnology has become cutting-edge technology. It is interdisciplinary and multidisciplinary, covering numerous fields such as medicine, engineering, biology, physics, material sciences, and chemistry. The present work aims to cover the optical properties, method of preparations, surface modifications, bio-conjugation, characterization, stability, and cytotoxicity of quantum dots (QDs). Articles were reviewed in English literature reporting the pharmaceutical and bio-pharmaceutical aspects of QDs which were indexed in Scopus, web of science, google scholar and PubMed without applying the year of publication criterion. One significant value of utilizing nanotechnology is that one can alter and control the properties in a genuinely unsurprising way to address explicit applications' issues. In science and biomedicine, the usage of functional nanomaterials has been broadly investigated and has become one of the quick-moving and stimulating research directions. Different types of nanomaterial (silicon nanowires, QDs, carbon nanotubes, nanoparticles of gold/silver) were extensively utilized for biological purposes. Nanomedicine shows numerous advantages in the natural characteristics of targeted drug delivery and therapeutics. For instance, protection of drugs against degradation, improvement in the drug's stability, prolonged circulation time, deceased side effects, and enhanced distribution in tissues. The present review article deals with the quantum dots, their optical properties, method of preparations, surface modifications, bio-conjugation, characterization, stability, and cytotoxicity of quantum dots. The review also discusses various biomedical applications of QDs. The QDs-based bio-nanotechnology will always be in the growing list of unique applications, with progress being made in specialized nanoparticle development, the detection of elegant conjugation methods, and the discovery of new targeting ligands.

Synthesis and Characterization of Polyvinylpyrrolidone-Modified ZnO Quantum Dots and Their In Vitro Photodynamic Tumor Suppressive Action.

Despite the numerous available treatments for cancer, many patients succumb to side effects and reoccurrence. Zinc oxide (ZnO) quantum dots (QDs) are inexpensive inorganic nanomaterials with potential applications in photodynamic therapy. To verify the photoluminescence of ZnO QDs and determine their inhibitory effect on tumors, we synthesized and characterized ZnO QDs modified with polyvinylpyrrolidone. The photoluminescent properties and reactive oxygen species levels of these ZnO/PVP QDs were also measured. Finally, in vitro and in vivo experiments were performed to test their photodynamic therapeutic effects in SW480 cancer cells and female nude mice. Our results indicate that the ZnO QDs had good photoluminescence and exerted an obvious inhibitory effect on SW480 tumor cells. These findings illustrate the potential applications of ZnO QDs in the fields of photoluminescence and photodynamic therapy.

High-Throughput Time-Resolved Photoluminescence Study of Composition- and Size-Selected Aqueous Ag–In–S Quantum Dots

Brightly luminescent, composition- and size-selected aqueous Ag–In–S (AIS) and Zn-diffused core/shell AIS/ZnS (ZAIS) quantum dots (QDs) were studied by high-throughput time-resolved photoluminescence (TRPL). Both QD size and QD composition effects on the photophysical properties of AIS (ZAIS) were probed independently by using an automated high-throughput TRPL setup. Linear relationships were found between the average PL lifetimes of AIS and ZAIS QDs and their respective bandgaps (Eg) indicating that the dynamics of the radiative recombination is governed mostly by the energy of the QD excited state irrespective of which factor is varied affecting the QD bandgap, i.e., their size or composition. The rate constants of radiative and nonradiative recombination were evaluated as a function of Eg forming continuous dependences for the entire AIS and ZAIS QD families. The rate of nonradiative recombination increases steeply for smaller QDs with Eg > 2.2 eV for both core AIS and core/shell ZAIS QDs, indicating that the interfacial electron transfer is the major contributor to the observed dependence. A strong decrease of the PL lifetime of AIS (and ZAIS) QDs in dense QD films or QDs incorporated into polyvinylpyrrolidone films was observed as compared to colloidal solutions. A reversible character of this effect upon polymer film dissolution shows that such behavior originates from energy (or electron) transfers among the QDs brought into close contact in the films. This phenomenon is expected to be of significance for the application of ternary QDs as a light-harvesting material.

Toxicity of quantum dots on target organs and immune system.

Quantum dots (QDs), due to their superior luminous properties, have been proven to be a very promising biological probe, which can be used as a candidate material for clinical applications. The toxicity of QDs in the environment and biological systems has caused widespread concern in the nanosphere, but their immune toxicity and their impact on the immune system are still relatively unknown. At present, the research on the toxicity of QDs is mainly focused on in vitro models, but few have systematically evaluated their adverse effects on target organs. Animal studies have shown that QDs can be accumulated in various organs due to their main exposure routes, thereby posing a potential threat to major organs. This review briefly describes general characteristics and the wide medical applications of QDs and focuses on the adverse effects of QDs on major target organs, such as liver, lung, kidney, brain, and spleen, after acute and chronic exposure. QDs mainly cause changes in the corresponding indicators of target organs, such as oxidative damage, and in severe cases cause hyperemia, tissue necrosis, and even death. In addition to causing direct damage to target organs, QDs can also cause a large number of immune cells to accumulate and cause inflammatory reactions when causing damage to other major organs. Whether it is to avoid the risk of people contacting QDs in production and life, or to realize the clinical applications of QDs, is very essential to conduct systematic in vivo toxicity assessment of QDs.