ACS Applied Nano Materials
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2022
·
IF 6.14
Liangliang Zhou,Bin Yu,Lilin Huang,Huiqun Cao,Danying Lin,Yingying Jing,Faiz Wali,Junle Qu
Colloidal quantum dots (QDs) are vital fluorescent probes with several optical features superior to those found in organic dyes for microscopy imaging. However, the emission blinking behavior of a single QD is an intrinsic drawback for stimulated emission depletion microscopy (STED) or structured illumination microscopy techniques. Herein, we present a rational strategy for the synthesis of a type of deterministic, environmentally friendly, small nonblinking core–multishell InP/ZnSe/ZnS QD using a hydrofluoric acid (HF) etching passivation. The strategy includes four steps: synthesis of the InP core, synthesis of oil-phase core–multishell InP/ZnSe/ZnS QDs using hydrogen fluoride and trioctylphosphine etching passivation, promotion of the water solubility of QDs modified by 3-mercaptopropionic acid (MPA), and enhanced biotargeting of core–multishell InP/ZnSe/ZnS QDs by surface coupling technology. The suppressed blinking mechanism was primarily attributed to surface wrapping shells and HF etching passivation of surface dangling bonds, which reduced surface nonradiative recombination. Nonblinking QDs exhibit high fluorescence efficiency (∼90%), good photostability (>20 min), a large Stokes shift (>135 nm), biocompatibility of the cell viability (>90%), and high targeting. Furthermore, super-resolution multifocal structured illumination microscopy imaging of subcellular structures labeled using these QDs confirmed a resolution improvement of greater than 2.6-fold compared to wide-field microscopy. The results indicate that the nonblinking QDs can function as excellent probes for use in the long-term super-resolution visualization of subcellular dynamics.
研究领域:
生物成像
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材料科学
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光学
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DOI
高影响因子
Journal of Materials Chemistry B
·
2017
·Vol. 5
·期 41
·8152-8160
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IF 4.543
Jie Zhang,Jie Wang,Tong Yan,Yanan Peng,Dajun Xu,Dawei Deng
Quantum dots (QDs) exhibit many unique optical properties, and show great promise as fluorescent markers in molecular, cellular and in vivo imaging. In this thematic issue, a major concern is their cytotoxicity. Among various Cd-free alternatives, InP-based QDs without highly toxic heavy metal elements have received the most attention. This article first focuses on the synthetic control of oil-soluble InP/ZnSe/ZnS QDs, exhibiting strong dual emissions, namely, visible excitonic emission and near-infrared (NIR) surface defect emission. Next, the organic-to-aqueous phase transfer of the dual emissive QDs was explored systematically. It was found that the dual emissions are relatively stable against the water transfer strategies used here; among them, aqueous dual emissive QDs obtained by wrapping oil-soluble QDs with a poly(acrylic acid)-octylamine (PAA-based) amphiphilic polymer (or modified with the cRGD peptide) exhibit enhanced NIR emission. Finally, using in vitro cell and in vivo small animal optical imaging techniques, the bioactivities of the cRGD-modified amphiphilic polymer-wrapped QDs were also investigated. The results confirm that single-wavelength excitation with strong dual emissions ranging from 550 to >1000 nm will endow the InP-based QDs with the capability for biomedical optical imaging across different spatial scales, as a promising alternative for Cd- and Pb-based QDs.
研究领域:
材料科学
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纳米技术
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生物医学工程
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光学成像
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产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Fan Shi,Shuangyi Yuan,Ranran Hu,Hang Xiao,Shaolu Zhang,Chenyang Wang,Xiangtong Zhang,Huaibin Shen
Indium phosphide (InP)-based quantum dots (QDs) have emerged as a promising alternative to cadmium-containing QDs for photonic applications. Nonetheless, the evolution of the synthesis chemistry for InP-based QDs poses a significant challenge, particularly with regard to morphological control. This study demonstrates efficient morphological control of square and spherical green-emissive InP/ZnSe/ZnS QDs. The formation of square-shaped QDs is attributed to the fluoride-induced suppression of {111} facet growth, which promotes shell growth along the {100} facets. Conversely, spherical QDs emerge owing to weak suppression of {111} facet growth. The fluoride is derived from the reaction between ZnF2 powder and oleic acid. It has been demonstrated that coordination between TOP and oleic acid effectively impedes this reaction. Beyond photoluminescence, the QDs exhibit strong and narrow radioluminescence (RL) at 565 nm with a full width at half maximum (FWHM) of 42 nm under X-ray excitation with a light yield of 4.2 × 103 photons/MeV. A QD X-ray imaging film was demonstrated to successfully visualize the internal components of opaque objects. This work demonstrates a ligand-mediated strategy for the morphological control of InP-based QDs and highlights their potential for X-ray imaging.
研究领域:
纳米材料
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量子点
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X射线成像
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合成化学
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光电子学
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产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2023
·Vol. 15
·期 46
·18920-18927
·
IF 6.7
Yaru Chen,Rixin Wang,Yanmin Kuang,Yangyang Bian,Fei Chen,Huaibin Shen,Zhen Chi,Xia Ran,Lijun Guo
Understanding the influence of the inner shell on fluorescence blinking and exciton dynamics is essential to promote the optical performances of InP-based quantum dots (QDs). Here, the fluorescence blinking, exciton dynamics, second-order correlation function g2(τ), and ultrafast carrier dynamics of InP/ZnSe/ZnS QDs regulated by the inner ZnSe shell thickness varying from 2 to 7 monolayers (MLs) were systematically investigated. With an inner ZnSe shell thickness of 5 MLs, the photoluminescence quantum yield (PL QY) can reach 98% due to the suppressed blinking and increased probability of multiphoton emission. The exciton dynamics of InP/ZnSe/ZnS QDs with different inner shells indicates that two decay components of neural excitons and charged trions are competitive to affect the photon emission behavior. The probability density distributions of the ON and OFF state duration in the blinking traces demonstrate an effective manipulation of the inner ZnSe shell in the non-radiative processes via defect passivation. Accordingly, the radiative recombination dominates the exciton deactivation and the non-radiative Auger recombination rate is remarkably reduced, leading to a QY close to unity and a high PL stability for InP/ZnSe/ZnS QDs with 5 MLs of the ZnSe shell. These results provide insights into the photophysical mechanism of InP-based QDs and are significant for developing novel semiconductor PL core/shell QDs.
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产品关联
DOI
PubMed
高影响因子
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