Small
·
2020
·Vol. 16
·期 14
·2001003
·
IF 11.459
Yejun Zhang,Hongchao Yang,Xinyi An,Zan Wang,Xiaohu Yang,Mengxuan Yu,Rong Zhang,Ziqiang Sun,Qiangbin Wang
Fluorescence in the second near-infrared window (NIR-II, 900–1700 nm) has drawn great interest for bioimaging, owing to its high tissue penetration depth and high spatiotemporal resolution. NIR-II fluorophores with high photoluminescence quantum yield (PLQY) and stability along with high biocompatibility are urgently pursued. In this work, a Ag-rich Ag 2 Te quantum dots (QDs) surface with sulfur source is successfully engineered to prepare a larger bandgap of Ag 2 S shell to passivate the Ag 2 Te core via a facile colloidal route, which greatly enhances the PLQY of Ag 2 Te QDs and significantly improves the stability of Ag 2 Te QDs. This strategy works well with different sized core Ag 2 Te QDs so that the NIR-II PL can be tuned in a wide range. In vivo imaging using the as-prepared Ag 2 Te@Ag 2 S QDs presents much higher spatial resolution images of organs and vascular structures as compared with the same dose of Ag 2 Te nanoprobes administrated, suggesting the success of the core–shell synthetic strategy and the potential biomedical applications of core–shell NIR-II nanoprobes.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2021
·
IF 9.811
Ming-Yu Zhang,An-An Liu,Haohao Fu,Wei Zhang,Shu-Han Zhang,Zhen-Ya Liu,Lin-Han Jiang,Xueguang Shao,Dai-Wen Pang
Precursor reactivity is crucial for the synthesis of Ag2Te quantum dots (QDs), which is helpful to obtain QDs with satisfactory properties. However, because of the inadequate understanding of the structure of Ag precursors, it is difficult to effectively regulate their reactivity. In this work, the Ag precursor reactivity can be regulated by modifying its structure with tertiary phosphines. Therefore, it is effective and convenient to precisely regulate the synthesis of Ag2Te QDs by changing the structure and amount of tertiary phosphine. The exciton absorption peak of Ag2Te QDs can be tuned in the range of 900–1150 nm, with the absolute photoluminescence quantum yield reaching 14.7%, and the full width at half-maximum of the photoluminescence peak being only 180 nm. This work provides a new insight into the regulation of precursor reactivity by altering its structure, which is conducive to the synthesis of high-quality nanocrystals.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2021
·
IF 15.419
Zhen-Ya Liu,An-An Liu,Haohao Fu,Qing-Yuan Cheng,Ming-Yu Zhang,Man-Man Pan,Li-Ping Liu,Meng-Yao Luo,Bo Tang,Wei Zhao,Juan Kong,Xueguang Shao,Dai-Wen Pang
Ag2Te is one of the most promising semiconductors with a narrow band gap and low toxicity; however, it remains a challenge to tune the emission of Ag2Te quantum dots (QDs) precisely and continuously in a wide range. Herein, Ag2Te QDs emitting from 950 to 2100 nm have been synthesized via trialkylphosphine-controlled growth. Trialkylphosphine has been found to induce the dissolution of small-sized Ag2Te QDs due to its stronger ability to coordinate to the Ag ion than that of 1-octanethiol, predicated by the density functional theory. By controlling this dissolution effect, the monomer supply kinetics can be regulated, achieving precise size control of Ag2Te QDs. This synthetic strategy results in state-of-the-art silver-based QDs with emission tunability. Only by taking advantage of such an ultrawide emission has the sizing curve of Ag2Te been obtained. Moreover, the absolute photoluminescence quantum yield of Ag2Te QDs can reach 12.0% due to their well-passivated Ag-enriched surface with a density of 5.0 ligands/nm2, facilitating noninvasive in vivo fluorescence imaging. The high brightness in the long-wavelength near-infrared (NIR) region makes the cerebral vasculature and the tiny vessel with a width of only 60 μm clearly discriminable. This work reveals a nonclassical growth mechanism of Ag2Te QDs, providing new insight into precisely controlling the size and corresponding photoluminescence properties of semiconductor nanocrystals. The ultrasmall, low-toxicity, emission-tunable, and bright NIR-II Ag2Te QDs synthesized in this work offer a tremendous promise for multicolor and deep-tissue in vivo fluorescence imaging.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Healthcare Materials
·
2019
·Vol. 8
·期 14
·1900341
·
IF 6.27
Jing-Jing Zhang,Yi Lin,Hui Zhou,He He,Jiao-Jiao Ma,Meng-Yao Luo,Zhi-Ling Zhang,Dai-Wen Pang
The advantages of fluorescence bioimaging in the second near-infrared (NIR II, 1000–1700 nm) window are well known; however, current NIR II fluorescent probes for in vivo tumor imaging still have many shortcomings, such as low fluorescence efficiency, unstable performance under in vivo environments, and inefficient enrichment at tumor sites. In this study, Ag 2 Te quantum dots (QDs) that emit light at a wavelength of 1300 nm are assembled with poly(lactic- co -glycolic acid) and further encapsulated within cancer cell membranes to overcome the shortcomings mentioned above. The as-prepared ≈100 nm biomimetic nanobioprobes exhibit ultrabright (≈60 times greater than that of free Ag 2 Te QDs) and highly stable (≈97% maintenance after laser radiation for 1 h) fluorescence in the NIR II window. By combining the active homotypic tumor targeting capability derived from the source cell membrane with the passive enhanced permeation and retention effect, improved accumulation at tumor sites ((31 ± 2)% injection dose per gram of tumor) and a high tumor-to-normal tissue ratio (13.3 ± 0.7) are achieved. In summary, a new biomimetic NIR II fluorescent nanobioprobe with ultrabright and stable fluorescence, homotypic targeting and good biocompatibility for enhanced in vivo tumor imaging is developed in this study.
研究领域:
生物工程
·
生物医学工程
·
分子影像
·
癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Bio Materials
·
2021
·
IF 0
Xue-Hui Shi,Ying-Ying Dai,Lei Wang,Zhi-Gang Wang,Shu-Lin Liu
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.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
·
光学
✓ 已验证
DOI
Nature Communications
·
2023
·Vol. 14
·期 1
·1-16
·
IF 16.6
Huang Biao,Tang Tao,Chen Shi-Hui,Li Hao,Sun Zhi-Jun,Zhang Zhi-Lin,Zhang Mingxi,Cui Ran
The blood-brain barrier breakdown, as a prominent feature after traumatic brain injury, always triggers a cascade of biochemical events like inflammatory response and free radical-mediated oxidative damage, leading to neurological dysfunction. The dynamic monitoring the status of blood-brain barrier will provide potent guidance for adopting appropriate clinical intervention. Here, we engineer a near-infrared-IIb Ag 2 Te quantum dot-based Mn single-atom catalyst for imaging-guided therapy of blood-brain barrier breakdown of mice after traumatic brain injury. The dynamic change of blood-brain barrier, including the transient cerebral hypoperfusion and cerebrovascular damage, could be resolved with high spatiotemporal resolution (150 ms and ~ 9.6 µm). Notably, the isolated single Mn atoms on the surface of Ag 2 Te exhibited excellent catalytic activity for scavenging reactive oxygen species to alleviate neuroinflammation in brains. The timely injection of Mn single-atom catalyst guided by imaging significantly promoted the reconstruction of blood-brain barrier and recovery of neurological function after traumatic brain injury.
研究领域:
神经科学
·
纳米技术
·
生物医学工程
·
诊疗学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Zheng Li,Jun Xu,Wei Xie,Dongbing Zhao,Zhen-Ya Liu,Xian Yang,Haohao Fu,Shijia Jiang,Wei Zhao,Ming-Yu Zhang,An-An Liu,Dai-Wen Pang
Surface ligands of quantum dots (QDs) play pivotal roles in determining their optical properties and stability during the growth process. The stability and continuous growth of nanocrystals are crucial to precisely tuning their properties. However, the dilemma surrounding the stability of nanocrystals and their continuous growth remains unsolved, posing a formidable challenge. Herein, we have proposed a strategy for precise tuning of Ag2Te QD growth driven by nucleophilic substitution reaction (SN2) between surface-bound thiol ligands and halogenated hydrocarbons (RX, X = Cl, Br, I), prompted by the generation of silver halide precipitate. As a result, Ag2Te QDs with emission wavelengths precisely and continuously tunable in the range of 1176–2023 nm have been successfully synthesized in one pot. As the reaction advances, the quantity of the more strongly coordinating RS– gradually diminishes, while that of the weaker coordinating dioctyl sulfide gradually increases. This dynamic process enables the growth of the QDs. The rate of the SN2 reaction can be adjusted by varying the species and concentration of RX, as well as the amount of Ag species, significantly influencing the growth rate of the QDs, a crucial factor for resolving the dilemma between the stability and tunability of the QDs. Additionally, this proposed strategy holds the potential to modulate the properties of various nanoparticles through chemical reactions at the interfaces.
研究领域:
材料科学
·
纳米技术
·
化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）