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Grafting of CdTe quantum dots on thiol functionalized MCM-41 mesoporous silica for 68Ga radiolabeling: introducing a novel PET agent
摘要： Radiolabeled fluorescent nanocomposite, 68Ga@CdTeQDs@SH-Propyl@MCM-41, was prepared. The prepared material was characterized using X-ray diffraction, thermal analysis, radio-thin layer chromatography, field Emission scanning electron microscopy, transmission electron microscopy and N2 adsorption and desorption measurements. In vivo biodistribution and tumor avidity of the nanoconposite was investigated among the organs of rats bearing fibro sarcoma tumor. The results showed that the mesoporous structure of MCM-41 after functionalization and grafting of quantum dots remains intact and the nanosilica can be labeled with 68Ga radionuclide very fast. The results showed a rapid and high tumor uptake for 68Ga@CdTeQDs@SH-Propyl@MCM-41 which revealed that the tumor uptake is modulated by size and character of the host.
关键词： CdTe Quantum Dots,68Ga-Radiolabeled fluorescent nanocomposite,MCM-41
更新于2025-09-23 15:21:01
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Dual-emission CdTe quantum dot@ZIF-365 ratiometric fluorescent sensor and application for highly sensitive detection of l-histidine and Cu2+
摘要： L-histidine acts as a semi-essential amino acid, which is medically used in the treatment of gastric ulcer, anemia, allergies. However, the overuse of L-histidine will result in terrible damage to heart disease, slow growth of animals and water pollution in the environment. In addition, Cu2+ pollution is common environmental pollution in the industry. It has the characteristics of high accumulation, migration, and persistence. Given this, through the post-synthesis strategy, CdTe quantum dots (QDs) were the first time to introduce into zeolitic imidazolate framework-ZIF-365 to synthesis dual-emission hybrid material CdTe@ZIF-365 with high quantum yield. TEM mappings and N2 absorption tests are applied to confirm the combination mode between CdTe quantum dots and ZIF-365. It should be noted that CdTe@ZIF-365 can be successfully utilized as a bi-functional ratiometric sensor for highly sensitive discrimination of L-histidine and Cu2+. Firstly, CdTe@ZIF-365 is applied to a fluorescent ratiometric sensor for Cu2+ with high sensitivity (the Ksv value is 2.7417(cid:1)107 [M-1]) and selectivity in the mixed cation ions’ solution. On the other hand, CdTe@ZIF-365 also behaved as the first example for an excellent ratiometric fluorescent senor for L-histidine with high sensitivity (the Ksv value is 6.0507(cid:1)108 [M-1]) and selectivity in the mixed amino acids’ solutions.
关键词： hybrid material,Cu2+,CdTe quantum dots,ratiometric fluorescent sensor,L-histidine
更新于2025-09-23 15:19:57
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MPA-CdTe quantum dots as a??on-off-ona?? sensitive fluorescence probe to detect ascorbic acid via redox reaction
摘要： Mercaptopropionic acid (MPA) capped CdTe quantum dots (MPA-CdTe QDs) were synthesized in aqueous medium by hydrothermal method, which modified by Fe3+ could be used as a fluorescent probe to detect ascorbic acid (AA). MPA-CdTe QDs fluorescence probe could be used as successive sensor for metal ions and AA with "on-off-on" process. The fluorescence of QDs was quenched after adding Fe3+ to MPA-CdTe QDs. Then, the fluorescence of the Fe3+@MPA-CdTe QDs can be sensitively turned on by AA to give an "on–off–on" fluorescence response according to the oxidation–reduction between Fe3+ and AA. There was a linear relationship between fluorescence intensity quenching value and the concentration of Fe3+ in the range of 2–10 μM since Fe3+ sensitively reacted with CdTe QDs. The linear detection range for AA was 0.1–1 μM with a limit of detection of 6.6 nM. The principle is proved by fluorescence emission spectroscopy, nuclear magnetic resonance spectroscopy. The proposed method is successfully used to detect the AA in human plasma sample.
关键词： CdTe quantum dots,Redox reaction,Fluorescent probe,Ascorbic acid
更新于2025-09-23 15:19:57
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Interactions between CdTe quantum dots and plasma proteins: kinetics, thermodynamics and molecular structure changes
摘要： Environmental particulate matter, especially ultrafine particles (< 100 nm in diameter), can damage the endothelium and favor cardiovascular disease in the general population. With the wide application of nanomaterials, exposure to nanoscale particles (nanoparticles) in the environment is increasing. Systematic study of the interaction of nanoparticles with plasma proteins is critically important for understanding the cardiovascular toxicity of nanomaterials. We combined kinetics and thermodynamics information from surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) and conformational data from fluorescence spectroscopy and circular dichroism (CD) to explore the binding mechanism between cadmium telluride quantum dots (CdTe QDs) and plasma proteins. Special attention was paid to the interaction between CdTe QDs and coagulation-related proteins and the effects of CdTe QDs on protein conformation. The results showed that the binding affinities of CdTe QDs and plasma proteins depend on the nature of the protein and follow the order of fibrinogen (FIB) > plasminogen (PLG) > thrombin (TM) > metallothionein-II (MT-II) > human serum albumin (HSA). The interaction was primarily attributed to hydrophobic forces and the spontaneity of the occurrence of the interaction, and the protein secondary structures of FIB and PLG were changed significantly. The information gained in this study might shed light on the potential toxicity of QDs to the cardiovascular system.
关键词： plasma proteins,circular dichroism,isothermal titration calorimetry,CdTe quantum dots,surface plasmon resonance
更新于2025-09-23 15:19:57
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Highly Sensitive Photoelectrochemical Biosensor Based on Quantum Dots Sensitizing Bi <sub/>2</sub> Te <sub/>3</sub> Nanosheets and DNA-Amplifying Strategies
摘要： In this work, the Bi2Te3 nanosheets treated by N-vinyl-Pyrrolidinone (NVP) showed the highly sufficient and stable photocurrent for being served as novel photoactive material. Accordingly, with CdTe quantum dots (QDs) sensitizing the Bi2Te3 nanosheets, a photoelectrochemical (PEC) biosensor coupling of DNA amplifying strategies was constructed for sensitive miRNA-21 detection. Initially, the Bi2Te3 nanosheets on electrode have conductive surface states with dissipationless electronic property, thus providing a highly stable photocurrent as well as large surface-to-volume ratio. Then, with the participation of target miRNA-21 and auxiliary DNA, the strand displacement amplification (SDA) took place, thereby opening substantial DNA hairpins for triggering next hybridization chain reaction (HCR). Through the HCR, long DNA tails decorated with CdTe QDs could thus be assembled on electrode for enhancing the photocurrent of Bi2Te3 nanosheets. As a result, the proposed PEC biosensor showed a wide detection range from 10 fM to 100 pM with a detection limit (LOD) of 3.3 fM, displaying a promising avenue to construct simply, ultrasensitive and stable analytical techniques and a tremendous potential in bioanalysis and early clinical diagnosis.
关键词： DNA amplifying strategies,Bi2Te3 nanosheets,sensitive detection,CdTe quantum dots,photoelectrochemical biosensor
更新于2025-09-23 15:19:57
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Chemical Synthesis and Characterization of Poly(poly(ethylene glycol) methacrylate)-Grafted CdTe Nanocrystals via RAFT Polymerization for Covalent Immobilization of Adenosine
摘要： This paper describes the functionalization of poly(poly(ethylene glycol) methacrylate) (PPEGMA)-grafted CdTe (PPEGMA-g-CdTe) quantum dots (QDs) via surface-initiated reversible addition–fragmentation chain transfer (SI-RAFT) polymerization for immobilization of adenosine. Initially, the hydroxyl-coated CdTe QDs, synthesized using 2-mercaptoethanol (ME) as a capping agent, were coupled with a RAFT agent, S-benzyl S'-trimethoxysilylpropyltrithiocarbonate (BTPT), through a condensation reaction. Then, 2,2'-azobisisobutyronitrile (AIBN) was used to successfully initiate in situ RAFT polymerization to generate PPEGMA-g-CdTe nanocomposites. Adenosine-above-PPEGMA-grafted CdTe (Ado-i-PPEGMA-g-CdTe) hybrids were formed by the polymer shell, which had successfully undergone bioconjugation and postfunctionalization by adenosine (as a nucleoside). Fourier transform infrared (FT-IR) spectrophotometry, energy-dispersive X-ray (EDX) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy results indicated that a robust covalent bond was created between the organic PPEGMA part, cadmium telluride (CdTe) QDs, and the adenosine conjugate. The optical properties of the PPEGMA-g-CdTe and Ado-i-PPEGMA-g-CdTe hybrids were investigated by photoluminescence (PL) spectroscopy, and the results suggest that they have a great potential for application as optimal materials in biomedicine.
关键词： poly(poly(ethylene glycol methacrylate),CdTe quantum dots,adenosine,SI-RAFT,covalent immobilization
更新于2025-09-19 17:15:36
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Surface functionalized quantum dots as biosensor for highly selective and sensitive detection of ppb level of propafenone
摘要： Monodispersed CdTe quantum dots (QDs) were prepared by using thioglycolic acid as surfactants in aqueous solution. The thioglycolic acid was chemically adsorbed on the surface of CdTe QDs that enables the QDs positively charged. In week acidic media, propafenone is positively charged, which can combine with the CdTe QDs to form larger ion-association complex via electrostatic attraction and hydrogen bond. Moreover, the formed ion-association complex could increase the intensity of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling-scattering (FDS) of CdTe QDs, and quench the CdTe QDs fluorescence. Importantly, under optimal experimental conditions, the increased RRS, SOS and FDS intensity, and quenched fluorescence intensity of CdTe QDs were in direct proportion to the propafenone concentration in a certain range, respectively. Among them, the RRS method exhibited the highest sensitivity. In a wide concentration range of propafenone from 0.003 to 7.0 mg mL?1, the detection limit could reach 0.96 ng mL?1, which was much lower than previously reported methods. To simulate practical applications, the possible foreign interfering substances were also investigated, such as common ions, amino acid, and glucide. The proposed method here is rapid, sensitive and shows promising application for detection of ppb level of propafenone in human serum.
关键词： Propafenone,CdTe quantum dots,Ion-association complex,Resonance Rayleigh scattering
更新于2025-09-16 10:30:52
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Investigations of rare earth doped CdTe QDs as sensitizers for quantum dots sensitized solar cells
摘要： Gd doped CdTe (Gd:CdTe) QDs sensitized working electrodes were fabricated for QDSSC applications. In this fabrication process, mercapto succinic acid capped Gd:CdTe QDs were synthesized by colloidal method and used as the sensitizer. Improved optical properties of the prepared QDs were examined by optical absorption and emission spectral analysis. Fluorescence quantum yield measurement reveals that 10% Gd:CdTe QDs shows the highest quantum yield of 67%. XRD analysis confirms the cubic zinc blende crystalline structure of the prepared QDs and the dopant concentration dependent cell parameters and crystallite sizes were revealed. Performance of capping molecules over the prepared QDs was analyzed by FT-IR studies. Enhanced photovoltaic performance of prepared pure and doped QDs was analyzed through J-V characteristic curves, which show better photovoltaic response with an efficiency of 2.24% for 10% Gd:CdTe QDs.
关键词： photo-conversion efficiency,QDSSC,working electrodes,Gd:CdTe,Quantum Dots
更新于2025-09-16 10:30:52
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Highly stable CdTe quantum dots hosted in gypsum <i>via</i> a flocculation–precipitation method
摘要： Poor stability hinders the practical application of aqueous CdTe quantum dots (QDs) in optoelectronic devices. In this work, a flocculation–precipitation method is demonstrated to host aqueous CdTe QDs in gypsum to form CdTe–gypsum nanocomposites, which is simple, effective and environmental-friendly. Ascribed to gypsum acting as a tight and robust matrix protection agent, the photo-, thermal-, anti-acid and long-term stability of CdTe QDs were remarkably improved. Moreover, this approach solved the problem of incompatibility between aqueous QDs and epoxy resin, allowing for the application of aqueous QDs in white light emitting diodes (WLEDs), based on which a WLED with the red-emission nanocomposites used as a color-conversion layer was successfully fabricated. These results indicate the potential of this technique in stabilizing aqueous QDs as well as their practical application in optoelectronic devices.
关键词： optoelectronic devices,stability,flocculation–precipitation method,CdTe quantum dots,gypsum
更新于2025-09-16 10:30:52
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Size dependence of photocatalytic hydrogen generation for CdTe quantum dots
摘要： CdTe quantum dots (QDs) are attractive photosensitizers for photocatalytic proton reduction due to their broad absorbance profile that can extend from the ultraviolet to near-infrared regions, providing access to a larger portion of the solar spectrum than possible with analogous CdSe and CdS QD photosensitizers. Here, the photocatalytic hydrogen (H2) generation from various sizes of dihydrolipoic acid (DHLA)-capped CdTe QDs, ranging from 2.5 to 7.5 nm in diameter, and a molecular Ni-DHLA catalyst in aqueous solutions was evaluated, and an unusual size-dependent photocatalytic activity with CdTe QDs was observed. Under optimized conditions, using 3.4 nm CdTe-DHLA and a 1:20 ratio of QD/Ni-DHLA catalyst, as many as 38 000 turnover numbers (mol H2 per mol QD) were achieved. However, below this critical size, the H2 production efficiency decreased; this behavior is attributed to the rapid oxidation of the QD surface, resulting in detrimental surface trap states. These results are consistent with ultrafast transient absorption spectroscopic measurements, which suggest the presence of extremely fast charge-trapping processes in the oxidized CdTe-DHLA QDs. While fast electron transfer from CdTe-DHLA QDs is observed in the presence of the Ni-DHLA catalyst, the charge trapping processes occur on a competitive time scale, thus lowering the efficiency of the CdTe/Ni-DHLA H2 production system. Understanding rapid charge trapping in CdTe QDs may help suggest potential improvements for the overall CdTe photocatalytic system.
关键词： size dependence,photocatalytic hydrogen generation,Ni-DHLA catalyst,CdTe quantum dots,dihydrolipoic acid
更新于2025-09-12 10:27:22