Quantum Dots
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(FIVE YEARS 18730)



2021 ◽  
Vol 240 ◽  
pp. 118463
Bing Xu ◽  
Haibin Chen ◽  
Tingting Zhang ◽  
Qing Long ◽  
Lishu Huang ◽  

2021 ◽  
Shibo Xu ◽  
Linna Chang ◽  
Xingjun Zhao ◽  
Yanan Hu ◽  
Shuocheng Huang ◽  

Abstract BackgroundHealing of MRSA (methicillin-resistant Staphylococcus aureus) infected deep burn wounds (MIDBW) in diabetic patients remains an obstacle, but is a cutting-edge research problem in clinical science. Surgical debridement and continuous antibiotic use remain the primary clinical treatment for MIDBW. However, suboptimal pharmacokinetics and high doses of antibiotics often cause serious side effects such as fatal complications of drug-resistant bacterial infections. MRSA, which causes wound infection, is currently a bacterium of concern in the treatment of diabetic wound healing, and in more severe cases it can even lead to amputation of the patient's limb.ResultsThe present work proposed a strategy of using EGCG (Epigallocatechin gallate) modified black phosphorus quantum dots (BPQDs) as a therapeutic nanoplatform for MIDBW to achieve the synergistic functions of NIR (near infrared)-response, ROS-generation, sterilization and promoted wound healing. The electron spin resonance results revealed that [email protected] had a stronger photocatalytic ability to produce singlet oxygen than [email protected] and the inhibition results indicated an effective bactericidal rate of 88.6% against MRSA. Molecular biology analysis demonstrated that EGCG-BPQDs significantly upregulated CD31 nearly 4-fold and basic fibroblast growth factor (bFGF) nearly 2-fold, which were beneficial for promoting proliferation of vascular endothelial cells and skin epidermal cells. Under NIR irradiation, EGCG-BPQDs hydrogel ([email protected]) treated MIDBW area could rapidly raise temperature up to 55°C for sterilization. The MIBDW closure rate of rat after 21 days of treatment was 92.4%, much better than that of 61.1% of the control group. The engineered [email protected] were found to promote MIDBW healing by triggering the PI3K/AKT and ERK1/2 signaling pathways, which could enhance cell proliferation and differentiation. In addition, intravenous circulation experiment showed good biocompatibility of [email protected], no obvious damage to rat major organs were observed.ConclusionsThe obtained results demonstrated that [email protected] achieved the synergistic functions of photocatalytic property, photothermal effects and promoted wound healing, and are promising multifunctional nanoplatforms for MIDBW healing in diabetics.

2021 ◽  
Vol 104 (11) ◽  
Frederick S. Thomas ◽  
Malin Nilsson ◽  
Carlo Ciaccia ◽  
Christian Jünger ◽  
Francesca Rossi ◽  

2021 ◽  
Vol 188 (10) ◽  
Klaudia Głowacz ◽  
Marcin Drozd ◽  
Patrycja Ciosek-Skibińska

AbstractThe presented work concerns pattern-based sensing with quantum dots for the identification and quantification of neurotransmitters by means of excitation-emission fluorescence spectroscopy (2D fluorescence). In the framework of this study, glutathione capped CdSeS/ZnS nanocrystals were used as non-specific nanoreceptors capable of differentiated interaction with neurotransmitters. The pattern-based sensing with QDs was realized by using excitation-emission fluorescence spectroscopy to provide analyte-specific multidimensional optical information. These characteristic fluorescent response patterns were processed by unfolded partial least squares–discriminant analysis, showing that satisfactory identification of all investigated neurotransmitters: dopamine, norepinephrine, epinephrine, serotonin, GABA, and acetylcholine, can be achieved through the proposed sensing strategy. The impact of the considered fluorescence signal (datum, i.e. zeroth-order data acquired per sample; spectrum, i.e. first-order data acquired per sample; excitation-emission matrix, i.e. second-order data acquired per sample) on the sensing capability of glutathione capped QDs was also verified. The best performance parameters such as accuracy, precision, sensitivity, and specificity were obtained using excitation-emission matrices (88.9–93.3%, 0.93–0.95, 0.89–0.93, and 0.99–1.00, respectively). Thus, it was revealed that excitation-emission fluorescence spectroscopy may improve the recognition of neurotransmitters while using only one type of nanoreceptor. Furthermore, is was demonstrated that the proposed excitation-emission fluorescence spectroscopy assisted QD assay coupled with unfolded partial least squares regression can be successfully utilized for quantitative determination of catecholamine neurotransmitters at the micromolar concentration range with R2 in the range 0.916–0.987. Consequently, the proposed sensing strategy has the potential to significantly simplify the sensing element and to expand the pool of bioanalytes so far detectable with the use of QDs. Graphical abstract

2021 ◽  
pp. 2101693
Zhaohan Li ◽  
Jing Wei ◽  
Fangfang Wang ◽  
Yanan Tang ◽  
Anming Li ◽  

2021 ◽  
Sue Jiun Phang ◽  
Jiale Lee ◽  
Voon-Loong Wong ◽  
Lling-Lling Tan ◽  
Siang-Piao Chai

Abstract Carbon quantum dots (CQDs) are particularly sought after for their highly tailorable photoelectrochemical and optical properties. Simultaneously, graphitic carbon nitride (g-C3N4) has also gained widespread attention due to its suitable band gap energy as well as excellent chemical and thermal stabilities. Herein, a novel boron-doped CQD (BCQD) hybridized g-C3N4 homojunction (CN) nanocomposite was rationally engineered and fabricated via a facile hydrothermal route. The optimal photocatalyst sample, 1-BCQD/CN (with a 1:3 mass ratio of boron to CQD) accomplished a Rhodamine B (RhB) degradation efficiency of 97.0 % within 4 hours under low-powered LED light irradiation. The kinetic rate constant of 1.39 x 10-2 min-1 achieved by the optimum sample was found to be 3.6- and 2.8-folds higher than that of pristine CN and un-doped CQD/CN, respectively. Furthermore, 1-BCQD/CN demonstrated remarkable stability, where it retained close to 99.0% of its initial photocatalytic efficiency after three consecutive cycles. The marked improvement in photocatalytic performance of 1-BCQD/CN was attributed to several concomitant factors such as enhanced electron migration from CN to BCQD, suppressed electron-hole recombination and significantly higher charge density in facilitating charge migration. Based on the scavenging tests, it was revealed that the photogenerated holes (h+), superoxide anions (∙O2–) and hydroxyl radicals (∙OH) were the primary reactive species responsible for the photodegradation process. Overall, the highly efficient 1-BCQD/CN composite with excellent photocatalytic activity could provide a cost-effective and robust means for addressing the increasing concerns over global environmental pollution.

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