Suppression of Blinking and Enhancement of Optical Properties of Core-Shell Quantum Dots by Structural Formulation

Rani, Sweta; Kumar, Jitendra

doi:10.1109/tnano.2020.3034369

Cited by 7 publications

(8 citation statements)

References 28 publications

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“…Certain ligands grafted onto the surface of QDs were found to reduce blinking rates . Similar reductions were obtained in alloyed core–shell interface systems or QDs possessing thick shells, ,− or by contacting QDs with noble metal NPs. − It is widely accepted that the blinking behavior of QDs is caused by two mechanisms. , The first Auger recombination, a nonradiative process in which excited state energy is transferred to charged QDs nearby, with the result of photoluminescence quenching . The second is via activation and deactivation of trap states on the QD surface.…”

Section: Fluorescent Nanoparticles Used In Super-resolution Microscop...mentioning

confidence: 80%

“…However, despite progress in suppressing surface traps, the problem of Auger recombination remains. Some progress has been made by softening the structure of QDs and thus avoiding interface discontinuities. − The effect is a lowering of spatial frequency components in the wave function which results in a partial suppression of the Auger process in charged NPs . In recent work, ultrafast mid-infrared (MIR) pulses (5.5 μm, 150 fs) with an appropriately selected field strength were applied to remove the excess electron from the trion-mediated Auger recombination in off-states of single core–shell CdSe/CdS QDs (Figure ).…”

Section: Fluorescent Nanoparticles Used In Super-resolution Microscop...mentioning

confidence: 99%

“…166−169 The effect is a lowering of spatial frequency components in the wave function which results in a partial suppression of the Auger process in charged NPs. 157 In recent work, ultrafast mid-infrared (MIR) pulses (5.5 μm, 150 fs) with an appropriately selected field strength were applied to remove the excess electron from the trion-mediated Auger recombination in off-states of single core−shell CdSe/CdS QDs (Figure 11). 151 The method led to a significant reduction in QD intensity flicker, and blinking could be almost eliminated in QDs encapsulated with thin (8 monolayers) shells.…”

Section: Quantum Dotsmentioning

confidence: 99%

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Fluorescent Nanoparticles for Super-Resolution Imaging

et al. 2022

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Super-resolution imaging techniques that overcome the diffraction limit of light have gained wide popularity for visualizing cellular structures with nanometric resolution. Following the pace of hardware developments, the availability of new fluorescent probes with superior properties is becoming ever more important. In this context, fluorescent nanoparticles (NPs) have attracted increasing attention as bright and photostable probes that address many shortcomings of traditional fluorescent probes. The use of NPs for super-resolution imaging is a recent development and this provides the focus for the current review. We give an overview of different super-resolution methods and discuss their demands on the properties of fluorescent NPs. We then review in detail the features, strengths, and weaknesses of each NP class to support these applications and provide examples from their utilization in various biological systems. Moreover, we provide an outlook on the future of the field and opportunities in material science for the development of probes for multiplexed subcellular imaging with nanometric resolution.

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Section: Fluorescent Nanoparticles Used In Super-resolution Microscop...mentioning

confidence: 80%

Section: Fluorescent Nanoparticles Used In Super-resolution Microscop...mentioning

confidence: 99%

Section: Quantum Dotsmentioning

confidence: 99%

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Fluorescent Nanoparticles for Super-Resolution Imaging

et al. 2022

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“…13,18 Comprehensive efforts have been made toward intrinsic nonblinking QDs based on these two mechanisms by passivating surface trap states and reducing the charge Auger recombination rate of the trap states through smoothening of the potential barrier between the core and shell layers of heteroepitaxial QDs. 19,20 There are relatively few studies on extrinsic blinking control. The addition of antiblinking agents, surface wrapping shells, and increased thickness of QDs can suppress blinking by passivating the QD surface.…”

Section: Introductionmentioning

confidence: 99%

“…The blinking of semiconductor QDs is generally considered to originate from two mechanisms, that is, surface trap-mediated nonradiative recombination and charge-induced Auger recombination of individual QDs. , Comprehensive efforts have been made toward intrinsic nonblinking QDs based on these two mechanisms by passivating surface trap states and reducing the charge Auger recombination rate of the trap states through smoothening of the potential barrier between the core and shell layers of heteroepitaxial QDs. , There are relatively few studies on extrinsic blinking control. The addition of antiblinking agents, surface wrapping shells, and increased thickness of QDs can suppress blinking by passivating the QD surface. − Although considerable progress has been made in suppressing QD blinking, the preparation of nonblinking QDs with high quantum yield, symmetric emission, good biocompatibility, and excellent crystallinity remains challenging.…”

Section: Introductionmentioning

confidence: 99%

Nonblinking Core–Multishell InP/ZnSe/ZnS Quantum Dot Bioconjugates for Super-resolution Imaging

Zhou

Huang

et al. 2022

ACS Appl. Nano Mater.

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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.

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Enhancement of fluorescence of single quantum dots by encasing in semiconductor and metal nanoparticles

Rani

Kumar

2021

Journal of Applied Physics

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Quantum dots (QDs) are widely investigated in the field of optoelectronics due to their various unique spectral and excellent fluorescence properties. However, QDs suffer from intermittent fluorescence, also known as blinking, that limits their use in optoelectronic devices. The blinking mechanism can be suppressed by numerous processes, and one such process includes the interaction of the QDs with semiconductor nanoparticles (NPs) such as indium tin oxide (ITO) and titanium dioxide (TiO2). By encapsulating the QDs in these NPs, the blinking rate is significantly reduced due to the electron transfer pathway between them. The interaction of QDs with metal NPs such as silver (Ag) and gold (Au) also greatly enhances the fluorescence behavior due to energy transfer and plasmonic effects. This work deals with the electron transfer model that analyzes the effect of radiative recombination, non-radiative recombination, and electron transfer between QDs and the NPs. An analysis of the on and off states for QDs under the influence of considered NPs has also been done. The on and off time for QDs have also been studied, which provide a comprehensive framework of the performance of the QDs interfaced with these NPs. A comparison between the QDs interacting with glass and other semiconductor and metal NPs is also drawn to compare the efficacy of QDs under the influence of different NPs. This analysis postulates the physical mechanism for blinking and ways to curb these mechanisms using the semiconductor and metal NPs. The theoretical study demonstrates the quantitative insights and prerequisites for designing QD-based optoelectronic devices.

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Suppression of Blinking and Enhancement of Optical Properties of Core-Shell Quantum Dots by Structural Formulation

Cited by 7 publications

References 28 publications

Fluorescent Nanoparticles for Super-Resolution Imaging

Fluorescent Nanoparticles for Super-Resolution Imaging

Nonblinking Core–Multishell InP/ZnSe/ZnS Quantum Dot Bioconjugates for Super-resolution Imaging

Enhancement of fluorescence of single quantum dots by encasing in semiconductor and metal nanoparticles

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