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Xu D, Shen LL, Qin ZK, Yan S, Wang N, Wang J, Gao YJ. Construction of Reverse Type-II InP/Zn xCd 1-xS Core/Shell Quantum Dots with Low Interface Strain to Enhance Photocatalytic Hydrogen Evolution. Inorg Chem 2024; 63:12582-12592. [PMID: 38917407 DOI: 10.1021/acs.inorgchem.4c01503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
The InP-based quantum dots (QDs) have attracted much attention in the field of photocatalytic H2 evolution. However, a shell should be used for InP-based photocatalytic systems to passivate the numerous surface defects. Different from the traditional InP-based core/shell QDs with Type-I or Type-II band alignment, herein, the "reverse Type-II" core/shell QDs in which both the conduction and valence bands of shell materials are more negative than those of core materials have been well-designed by regulating the ratio of Cd/Zn of the alloyed ZnxCd1-xS shell. The reverse Type-II band alignment would realize the spatial separation of photogenerated carriers. More importantly, the photogenerated holes tend to rest on the shell in the reverse Type-II QDs, which facilitate hole transfer to the surface, the rate-determining step for solar H2 evolution using QDs. Therefore, the obtained InP/Zn0.25Cd0.75S core/shell QDs exhibit superior photocatalytic activity and stability under visible light irradiation. The rate of solar H2 evolution reaches 376.19 μmol h-1 mg-1 at the initial 46 h, with a turnover number of ∼2,157,000 per QD within 70 h irradiation.
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Affiliation(s)
- Dongzi Xu
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
| | - Li-Lei Shen
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
| | - Zhi-Kai Qin
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
| | - Shuo Yan
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
| | - Nianxing Wang
- Department of Mechanical and Materials Engineering, University of Turku, Turku 20014, Finland
| | - Jingui Wang
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
| | - Yu-Ji Gao
- School of Chemistry and Chemical Engineering, Faculty of Chemistry and Pharmacy, Qilu University of Technology (Shandong Academy of Science), Jinan 250353, P. R. China
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Hasan AMM, Susan MABH. Synergism in carbon nanotubes and carbon-dots: counter electrode of a high-performance dye-sensitized solar cell. RSC Adv 2024; 14:7616-7630. [PMID: 38440284 PMCID: PMC10911412 DOI: 10.1039/d4ra00601a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 02/27/2024] [Indexed: 03/06/2024] Open
Abstract
Dye-sensitized solar cells (DSSCs) play a crucial role in the realm of renewable energy technology by converting solar energy into electrical energy in an efficient and cost-effective way. In the pursuit of improving the photoconversion efficiency (PCE) of DSSCs, this work aims at fabricating a new counter electrode (CE) using a binary composite of heteroatom-doped carbon dots (C-dots) and functionalized multi-walled carbon nanotubes (o-MWCNTs). We demonstrate that this binary composite exhibits superior performance to pristine o-MWCNTs, resulting in a remarkable enhancement in the PCE. The PCE of the o-MWCNT/C-dots composite was measured at an impressive 4.28%, significantly outperforming the pristine o-MWCNT electrode, which yielded an efficiency of 2.24%. The enhanced performance of the o-MWCNT/C-dots composite can be attributed to the synergistic effects of heteroatom-doped C-dots since their binding to the o-MWCNTs by activated oxygenic surface functional groups increases the surface area from 218 to 253 m2 g-1. This enhanced surface area results from the reduction of π-π stacking interactions of the individual tubes and production of a new hollow channel in the structure that provides an ideal scaffold for I2 adsorption and electron transfer. We demonstrate the role of C-dots on MWCNT's property modulation toward higher PCE by density functional theory (DFT) calculation and electrochemical analysis. Electron-excess N and S doped C-dots exhibit strong catalytic activity, allowing for rapid electron transfer processes in the CE-electrolyte surface via the donor acceptor mechanism, whereas electron-deficient B doped C-dots undermine the cell performance by forming a charge recombination trap at the CE surface. The synthesized composite has higher redox reversibility up to 100 CV cycles and chemical stability, studied by the post-performance material characterization. The findings offer a promising avenue for the development of high-performance DSSCs, which will help to promote sustainable and renewable energy technologies.
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Affiliation(s)
| | - Md Abu Bin Hasan Susan
- Department of Chemistry, University of Dhaka Dhaka-1000 Bangladesh
- Dhaka University Nanotechnology Center (DUNC), University of Dhaka Dhaka-1000 Bangladesh
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Roy D, De CK, Ghosh S, Mukherjee S, Mandal S, Mandal PK. Ultrafast dynamics and ultrasensitive single particle spectroscopy of optically robust core/alloy shell semiconductor quantum dots. Phys Chem Chem Phys 2022; 24:8578-8590. [PMID: 35355030 DOI: 10.1039/d1cp05780d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A "one-pot one-step" synthesis method of Core/Alloy Shell (CAS) quantum dots (QDs) offers the scope of large scale synthesis in a less time consuming, more economical, highly reproducible and high-throughput manner in comparison to "multi-pot multi-step" synthesis for Core/Shell (CS) QDs. Rapid initial nucleation, and smooth & uniform shell growth lead to the formation of a compositionally-gradient alloyed hetero-structure with very significantly reduced interfacial trap density in CAS QDs. Thus, interfacial strain gets reduced in a much smoother manner leading to enhanced confinement for the photo-generated charge carriers in CAS QDs. Convincing proof of alloy-shelling for a CAS QD has been provided from HRTEM images at the single particle level. The band gap could be tuned as a function of composition, temperature, reactivity difference of precursors, etc. and a high PLQY and improved photochemical stability could be achieved for a small sized CAS QD. From the ultrafast exciton dynamics in CdSe and InP CAS QDs, it has been shown that (a) the hot exciton thermalization/relaxation happens in <500 fs, (b) hot electron trapping dynamics occurs within a ∼1 ps time scale, (c) band edge exciton trapping occurs within a 10-25 ps timescale and (d) for CdSe CAS QDs the hot hole gets trapped in about 35 ps. From fast PL decay dynamics, it has been shown that the amplitude of the intermediate time constant can be correlated with the PLQY. A model has been provided to understand these ultrafast to fast exciton dynamical processes. At the ultrasensitive single particle level, unlike CS QDs, CdSe CAS QDs have been shown to exhibit (a) constancy of PLmax (i.e. no bluing) and (b) constancy of PL intensity (i.e. no bleaching) of the single CAS QDs for continuous irradiation for one hour under an air atmosphere. Thus, CAS QDs hold the promise of being a superior optical probe in comparison to CS QDs both at the ensemble and at the single particle level, leading to enhanced flexibility of the CAS QDs towards designing and developing next generation application devices.
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Affiliation(s)
- Debjit Roy
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India.
| | - Chayan K De
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India.
| | - Swarnali Ghosh
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India.
| | - Soumen Mukherjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India.
| | - Saptarshi Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India.
| | - Prasun K Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India. .,Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, West Bengal, 741246, India
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Park J, Won YH, Han Y, Kim HM, Jang E, Kim D. Tuning Hot Carrier Dynamics of InP/ZnSe/ZnS Quantum Dots by Shell Morphology Control. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2105492. [PMID: 34889031 DOI: 10.1002/smll.202105492] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/05/2021] [Indexed: 06/13/2023]
Abstract
Isotropic InP/ZnSe/ZnS quantum dots (QDs) are prepared at a high reaction temperature, which facilitates ZnSe shell growth on random facets of the InP core. Fast crystal growth enables stacking faults elimination, which induces anisotropic growth, and as a result, improves the photoluminescence (PL) quantum yield by nearly 20%. Herein, the effect of the QD morphology on photophysical properties is investigated by observing the PL blinking and ultrafast charge carrier dynamics. It is found that hot hole trapping is considerably suppressed in isotropic InP QDs, indicating that the stacking faults in the anisotropic InP/ZnSe structures act as defects for luminescence. These results highlight the importance of understanding the correlation between QD shapes and hot carrier dynamics, and present a way to design highly luminescent QDs for further promising display applications.
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Affiliation(s)
- Jumi Park
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Yu-Ho Won
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, Republic of Korea
| | - Yongseok Han
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, Republic of Korea
| | - Hyun-Mi Kim
- Korea Electronics Technology Institute, 25 Saenari-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13509, Republic of Korea
| | - Eunjoo Jang
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, Republic of Korea
| | - Dongho Kim
- Department of Chemistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
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5
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Stewart JC, Fan Y, Danial JSH, Goetz A, Prasad AS, Burton OJ, Alexander-Webber JA, Lee SF, Skoff SM, Babenko V, Hofmann S. Quantum Emitter Localization in Layer-Engineered Hexagonal Boron Nitride. ACS NANO 2021; 15:13591-13603. [PMID: 34347438 DOI: 10.1021/acsnano.1c04467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Hexagonal boron nitride (hBN) is a promising host material for room-temperature, tunable solid-state quantum emitters. A key technological challenge is deterministic and scalable spatial emitter localization, both laterally and vertically, while maintaining the full advantages of the 2D nature of the material. Here, we demonstrate emitter localization in hBN in all three dimensions via a monolayer (ML) engineering approach. We establish pretreatment processes for hBN MLs to either fully suppress or activate emission, thereby enabling such differently treated MLs to be used as select building blocks to achieve vertical (z) emitter localization at the atomic layer level. We show that emitter bleaching of ML hBN can be suppressed by sandwiching between two protecting hBN MLs, and that such thin stacks retain opportunities for external control of emission. We exploit this to achieve lateral (x-y) emitter localization via the addition of a patterned graphene mask that quenches fluorescence. Such complete emitter site localization is highly versatile, compatible with planar, scalable processing, allowing tailored approaches to addressable emitter array designs for advanced characterization, monolithic device integration, and photonic circuits.
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Affiliation(s)
- James Callum Stewart
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Ye Fan
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - John S H Danial
- The Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Alexander Goetz
- Institute of Atomic and Subatomic Physics, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria
| | - Adarsh S Prasad
- Institute of Atomic and Subatomic Physics, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria
| | - Oliver J Burton
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Jack A Alexander-Webber
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Steven F Lee
- The Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Sarah M Skoff
- Institute of Atomic and Subatomic Physics, Vienna University of Technology, Stadionallee 2, 1020 Vienna, Austria
| | - Vitaliy Babenko
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
| | - Stephan Hofmann
- Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom
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6
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Guryev EL, Shanwar S, Zvyagin A, Deyev SM, Balalaeva IV. Photoluminescent Nanomaterials for Medical Biotechnology. Acta Naturae 2021; 13:16-31. [PMID: 34377553 PMCID: PMC8327149 DOI: 10.32607/actanaturae.11180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/12/2020] [Indexed: 12/20/2022] Open
Abstract
Creation of various photoluminescent nanomaterials has significantly expanded the arsenal of approaches used in modern biomedicine. Their unique photophysical properties can significantly improve the sensitivity and specificity of diagnostic methods, increase therapy effectiveness, and make a theranostic approach to treatment possible through the application of nanoparticle conjugates with functional macromolecules. The most widely used nanomaterials to date are semiconductor quantum dots; gold nanoclusters; carbon dots; nanodiamonds; semiconductor porous silicon; and up-conversion nanoparticles. This paper considers the promising groups of photoluminescent nanomaterials that can be used in medical biotechnology: in particular, for devising agents for optical diagnostic methods, sensorics, and various types of therapy.
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Affiliation(s)
- E. L. Guryev
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022 Russia
| | - S. Shanwar
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022 Russia
| | - A.V. Zvyagin
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022 Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia
- I. M. Sechenov First Moscow State Medical University, Moscow, 119991 Russia
| | - S. M. Deyev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997 Russia
- I. M. Sechenov First Moscow State Medical University, Moscow, 119991 Russia
| | - I. V. Balalaeva
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022 Russia
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7
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Volokh M, Mokari T. Metal/semiconductor interfaces in nanoscale objects: synthesis, emerging properties and applications of hybrid nanostructures. NANOSCALE ADVANCES 2020; 2:930-961. [PMID: 36133041 PMCID: PMC9418511 DOI: 10.1039/c9na00729f] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/04/2020] [Indexed: 05/11/2023]
Abstract
Hybrid nanostructures, composed of multi-component crystals of various shapes, sizes and compositions are much sought-after functional materials. Pairing the ability to tune each material separately and controllably combine two (or more) domains with defined spatial orientation results in new properties. In this review, we discuss the various synthetic mechanisms for the formation of hybrid nanostructures of various complexities containing at least one metal/semiconductor interface, with a focus on colloidal chemistry. Different synthetic approaches, alongside the underlying kinetic and thermodynamic principles are discussed, and future advancement prospects are evaluated. Furthermore, the proved unique properties are reviewed with emphasis on the connection between the synthetic method and the resulting physical, chemical and optical properties with applications in fields such as photocatalysis.
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Affiliation(s)
- Michael Volokh
- Department of Chemistry, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev Beer-Sheva 8410501 Israel
| | - Taleb Mokari
- Department of Chemistry, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev Beer-Sheva 8410501 Israel
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8
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Zhang L, Lv B, Yang H, Xu R, Wang X, Xiao M, Cui Y, Zhang J. Quantum-confined stark effect in the ensemble of phase-pure CdSe/CdS quantum dots. NANOSCALE 2019; 11:12619-12625. [PMID: 31233067 DOI: 10.1039/c9nr03061a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Colloidal semiconductor quantum dots (QDs) have recently attracted great attention in electric field sensing via the quantum-confined Stark effect (QCSE), but they suffer from the random local electric field around the charged QDs through the Auger process or defect traps. Here, QCSE in the ensemble of phase-pure wurtzite CdSe/CdS QDs was studied by applying a uniform external electric field. We observed clear field-dependent photoluminescence (PL) and absorption characteristics in thick-shell CdSe/CdS QDs with 11 CdS monolayers (11 MLs) including a pronounced spectral redshift in PL of ∼2.3 nm and absorption of ∼2.1 nm. The time-dependent PL intensity traces implied that the thick-shell QDs were conducive to realize the Stark shift in QD ensembles due to the effective suppression of the main sources of the local field. These findings were in stark contrast to those of moderate-shell (5 MLs) and ultrathick-shell (15 MLs) CdSe/CdS QDs. The measurement value of exciton polarizability was smaller than the theoretical value, which may be influenced by very few exciton traps. Moreover, the amplified stimulated emission also exhibited obvious optical modulations under the electric field with decreased emission intensity and an increased ultrafast lifetime. Finally, the temporal evolution of the multiexciton process in thick-shell CdSe/CdS QDs indicated that the multiexciton state induced a higher energy state near the band edge, which may weaken the QCSE of a single exciton. Therefore, it was demonstrated that efficient field control over the optical properties of these nanomaterials is feasible and this can open up potential applications in field-controlled electro-optic modulators.
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Affiliation(s)
- Lei Zhang
- Advanced Photonics Center, Southeast University, Nanjing 210096, China.
| | - Bihu Lv
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Hongyu Yang
- Advanced Photonics Center, Southeast University, Nanjing 210096, China.
| | - Ruilin Xu
- Advanced Photonics Center, Southeast University, Nanjing 210096, China.
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Yiping Cui
- Advanced Photonics Center, Southeast University, Nanjing 210096, China.
| | - Jiayu Zhang
- Advanced Photonics Center, Southeast University, Nanjing 210096, China.
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9
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Otero C, Carreño A, Polanco R, Llancalahuen FM, Arratia-Pérez R, Gacitúa M, Fuentes JA. Rhenium (I) Complexes as Probes for Prokaryotic and Fungal Cells by Fluorescence Microscopy: Do Ligands Matter? Front Chem 2019; 7:454. [PMID: 31297366 PMCID: PMC6606945 DOI: 10.3389/fchem.2019.00454] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/07/2019] [Indexed: 12/22/2022] Open
Abstract
Re(I) complexes have exposed highly suitable properties for cellular imaging (especially for fluorescent microscopy) such as low cytotoxicity, good cellular uptake, and differential staining. These features can be modulated or tuned by modifying the ligands surrounding the metal core. However, most of Re(I)-based complexes have been tested for non-walled cells, such as epithelial cells. In this context, it has been proposed that Re(I) complexes are inefficient to stain walled cells (i.e., cells protected by a rigid cell wall, such as bacteria and fungi), presumably due to this physical barrier hampering cellular uptake. More recently, a series of studies have been published showing that a suitable combination of ligands is useful for obtaining Re(I)-based complexes able to stain walled cells. This review summarizes the main characteristics of different fluorophores used in bioimage, remarking the advantages of d6-based complexes, and focusing on Re(I) complexes. In addition, we explored different structural features of these complexes that allow for obtaining fluorophores especially designed for walled cells (bacteria and fungi), with especial emphasis on the ligand choice. Since many pathogens correspond to bacteria and fungi (yeasts and molds), and considering that these organisms have been increasingly used in several biotechnological applications, development of new tools for their study, such as the design of new fluorophores, is fundamental and attractive.
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Affiliation(s)
- Carolina Otero
- Facultad de Medicina, Escuela de Química y Farmacia, Universidad Andres Bello, Santiago, Chile
| | - Alexander Carreño
- Center for Applied Nanosciences (CANS), Universidad Andres Bello, Santiago, Chile
| | - Rubén Polanco
- Facultad de Ciencias de la Vida, Centro de Biotecnología Vegetal, Universidad Andres Bello, Santiago, Chile
| | - Felipe M Llancalahuen
- Facultad de Medicina, Escuela de Química y Farmacia, Universidad Andres Bello, Santiago, Chile
| | - Ramiro Arratia-Pérez
- Center for Applied Nanosciences (CANS), Universidad Andres Bello, Santiago, Chile
| | - Manuel Gacitúa
- Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago, Chile
| | - Juan A Fuentes
- Laboratorio de Genética y Patogénesis Bacteriana, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
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Lim M, Lee W, Bang G, Lee WJ, Park Y, Kwon Y, Jung Y, Kim S, Bang J. Synthesis of far-red- and near-infrared-emitting Cu-doped InP/ZnS (core/shell) quantum dots with controlled doping steps and their surface functionalization for bioconjugation. NANOSCALE 2019; 11:10463-10471. [PMID: 31112192 DOI: 10.1039/c9nr02192b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this study, we designed and synthesized far-red- and near-infrared-emitting Cu-doped InP-based quantum dots (QDs), and we also demonstrated their highly specific and sensitive biological imaging ability. Cu-doped InP/ZnS (core/shell) QDs were prepared using the hot colloidal synthesis method in the organic phase. The ZnS shell passivates the surface and improves the photoluminescence (PL) intensity. However, the InP : Cu/ZnS (core : dopants/shell) QDs, which were obtained after the Cu dopant was incorporated into bare InP QDs, followed by ZnS shell coating, had relatively low PL intensities (maximum PL quantum yield (QY) was only ∼16%) presumably due to the formation of defect sites in the InP-core QDs caused by dopant migration from the InP core to the ZnS shell. We prepared high-quality InP/ZnS : Cu/ZnS (core/shell : dopant/outer-shell) QDs, where thin ZnS shell layers were grown on bare InP QDs prior to Cu ion doping to prevent dopant migration and obtained PL QYs as high as 40%. The native hydrophobic ligands of the as-synthesized Cu-doped QDs were replaced with hydrophilic ligands including dihydrolipoic acid and a zwitterionic ligand, which rendered the QDs water-soluble. These QDs exhibited remarkable colloidal stabilities over a wide pH range, with hydrodynamic diameters less than 10 nm. Modified QD surfaces can also be used in conjugation with other functional moieties to apply highly specific and sensitive imaging probes with very low background levels. As a proof-of-concept study, we successfully demonstrated the selective imaging of streptavidin beads with biotin-conjugated QDs. These decorated Cu-doped InP/ZnS (core/shell) QDs are promising biological-probe candidates for imaging and assaying with reduced concerns regarding toxicity.
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Affiliation(s)
- Mihye Lim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Namgu, Pohang 37673, Republic of Korea.
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11
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Guo X, Kuang Y, Wang S, Li Z, Shen H, Guo L. Shell-dependent blinking behavior and fluorescence dynamics of single ZnSe/CdS core/shell quantum dots. NANOSCALE 2018; 10:18696-18705. [PMID: 30270388 DOI: 10.1039/c8nr06749j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
An understanding of blinking behavior and photodynamics is crucial for improving the optical properties of quantum dots (QDs). Here we report the emission blinking behavior and dynamical mechanisms of single ZnSe/CdS core/shell QDs with the shell thickness varying from 1 to 6 monolayers. We find that the emission blinking behavior can be efficiently suppressed in the single-exciton regime and that the photoluminescence (PL) quantum yields (QY) and the corresponding fraction-bright of ZnSe/CdS QDs can be optimized by regulating the shell thickness. Specifically, the PL QY reaches a maximum of 93% when the shell thickness is 4 monolayers. The intensity-resolved and time-resolved fluorescence dynamics of single QDs indicate that three exciton decay pathways via trion emission, band-edge emission and shallow surface trap-state emission contribute to the blinking behavior of ZnSe/CdS QDs. The competitive contribution ratios of these three decay components are responsible for the significant difference in emission properties of ZnSe/CdS QDs with different shell thicknesses. Our findings in this work demonstrate that an effective way to improve the quantum yields and fraction-bright of core/shell QDs is to enhance the band-edge emission while suppressing the trion emission and surface trap-state emission.
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Affiliation(s)
- Xing Guo
- Institute of Micro/Nano Photonic Materials and Application, School of Physics and Electronics, Henan University, Kaifeng, 475004, People's Republic of China.
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12
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Pramanik S, Bhandari S, Pan UN, Roy S, Chattopadhyay A. A White Light-Emitting Quantum Dot Complex for Single Particle Level Interaction with Dopamine Leading to Changes in Color and Blinking Profile. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800323. [PMID: 29665212 DOI: 10.1002/smll.201800323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/19/2018] [Indexed: 06/08/2023]
Abstract
The interaction of the neurotransmitter dopamine is reported with a single particle white light-emitting (WLE) quantum dot complex (QDC). The QDC is composed of yellow emitting ZnO quantum dots (Qdots) and blue emitting Zn(MSA)2 complex (MSA = N-methylsalicylaldimine) synthesized on their surfaces. Sensing is achieved by the combined changes in the visual luminescence color from white to blue, chromaticity color coordinates from (0.31, 0.33) to (0.24, 0.23) and the ratio of the exponents (αon /αoff ) of on/off probability distribution (from 0.24 to 3.21) in the blinking statistics of WLE QDC. The selectivity of dopamine toward ZnO Qdots, present in WLE QDC, helps detect ≈13 dopamine molecules per Qdot. Additionally, the WLE QDC exhibits high sensitivity, with a limit of detection of 3.3 × 10-9 m (in the linear range of 1-100 × 10-9 m) and high selectivity in presence of interfering biological species. Moreover, the single particle on-off bilking statistics based detection strategy may provide an innovative way for ultrasensitive detection of analytes.
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Affiliation(s)
- Sabyasachi Pramanik
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Satyapriya Bhandari
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Uday Narayan Pan
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Shilaj Roy
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Arun Chattopadhyay
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
- Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
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Yuan G, Gómez DE, Kirkwood N, Boldt K, Mulvaney P. Two Mechanisms Determine Quantum Dot Blinking. ACS NANO 2018; 12:3397-3405. [PMID: 29579376 DOI: 10.1021/acsnano.7b09052] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Many potential applications of quantum dots (QDs) can only be realized once the luminescence from single nanocrystals (NCs) is understood. These applications include the development of quantum logic devices, single-photon sources, long-life LEDs, and single-molecule biolabels. At the single-nanocrystal level, random fluctuations in the QD photoluminescence occur, a phenomenon termed blinking. There are two competing models to explain this blinking: Auger recombination and surface trap induced recombination. Here we use lifetime scaling on core-shell chalcogenide NCs to demonstrate that both types of blinking occur in the same QDs. We prove that Auger-blinking can yield single-exponential on/off times in contrast to earlier work. The surface passivation strategy determines which blinking mechanism dominates. This study summarizes earlier studies on blinking mechanisms and provides some clues that stable single QDs can be engineered for optoelectronic applications.
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Affiliation(s)
- Gangcheng Yuan
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | | | - Nicholas Kirkwood
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Klaus Boldt
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, School of Chemistry , University of Melbourne , Parkville , Victoria 3010 , Australia
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14
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Enright MJ, Cossairt BM. Synthesis of tailor-made colloidal semiconductor heterostructures. Chem Commun (Camb) 2018; 54:7109-7122. [DOI: 10.1039/c8cc03498b] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This feature article provides an account of the various bottom-up and top-down methods that have been developed to prepare colloidal heterostructures and highlights the benefits of a seeded assembly approach for greater control and customizability.
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15
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Roy D, Mandal S, De CK, Kumar K, Mandal PK. Nearly suppressed photoluminescence blinking of small-sized, blue–green–orange–red emitting single CdSe-based core/gradient alloy shell/shell quantum dots: correlation between truncation time and photoluminescence quantum yield. Phys Chem Chem Phys 2018; 20:10332-10344. [DOI: 10.1039/c8cp00952j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nearly suppressed PL blinking of small sized CdSe based CGASS QDs.
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Affiliation(s)
- Debjit Roy
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Kolkata
- Mohanpur
- India
| | - Saptarshi Mandal
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Kolkata
- Mohanpur
- India
| | - Chayan K. De
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Kolkata
- Mohanpur
- India
| | - Kaushalendra Kumar
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Kolkata
- Mohanpur
- India
| | - Prasun K. Mandal
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Kolkata
- Mohanpur
- India
- Centre for Advanced Functional Materials
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16
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Ratiometric fluorescent sensing of copper ion based on chromaticity change strategy. Anal Bioanal Chem 2017; 409:6655-6662. [DOI: 10.1007/s00216-017-0621-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/22/2017] [Accepted: 09/01/2017] [Indexed: 12/21/2022]
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17
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Robinson RT, Huppler AR. The Goldilocks model of immune symbiosis with Mycobacteria and Candida colonizers. Cytokine 2017; 97:49-65. [PMID: 28570933 DOI: 10.1016/j.cyto.2017.05.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
Abstract
Mycobacteria and Candida species include significant human pathogens that can cause localized or disseminated infections. Although these organisms may appear to have little in common, several shared pathways of immune recognition and response are important for both control and infection-related pathology. In this article, we compare and contrast the innate and adaptive components of the immune system that pertain to these infections in humans and animal models. We also explore a relatively new concept in the mycobacterial field: biological commensalism. Similar to the well-established model of Candida infection, Mycobacteria species colonize their human hosts in equilibrium with the immune response. Perturbations in the immune response permit the progression to pathologic disease at the expense of the host. Understanding the immune factors required to maintain commensalism may aid with the development of diagnostic and treatment strategies for both categories of pathogens.
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Affiliation(s)
- Richard T Robinson
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.
| | - Anna R Huppler
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Pediatrics, Division of Infectious Disease, Medical College of Wisconsin, Children's Hospital and Health System, Children's Research Institute, Milwaukee, WI, USA.
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18
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Gao F, Bajwa P, Nguyen A, Heyes CD. Shell-Dependent Photoluminescence Studies Provide Mechanistic Insights into the Off-Grey-On Transitions of Blinking Quantum Dots. ACS NANO 2017; 11:2905-2916. [PMID: 28221750 DOI: 10.1021/acsnano.6b08040] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The majority of quantum dot (QD) blinking studies have used a model of switching between two distinct fluorescence intensity levels, "on" and "off". However, a distinct intermediate intensity level has been identified in some recent reports, a so-called "grey" or "dim" state, which has brought this binary model into question. While this grey state has been proposed to result from the formation of a trion, it is still unclear under which conditions it is present in a QD. By performing shell-dependent blinking studies on CdSe QDs, we report that the populations of the grey state and the on state are strongly dependent on both the shell material and its thickness. We found that adding a ZnS shell did not result in a significant population of the grey state. Using ZnSe as the shell material resulted in a slightly higher population of the grey state, although it was still poorly resolved. However, adding a CdS shell resulted in the population of a grey state, which depended strongly on its thickness up to 5 ML. Interestingly, while the frequency of transitions to and from the grey state showed a very strong dependence on CdS shell thickness, the brightness of and the dwell time in the grey state did not. Moreover, we found that the grey state acts as an on-pathway intermediate state between on and off states, with the thickness of the shell determining the transition probability between them. We also identified two types of blinking behavior in QDs, one that showed long-lived but lower intensity on states and another that showed short-lived but brighter on states that also depended on the shell thickness. Intensity-resolved single QD fluorescence lifetime analysis was used to identify the relationship between the various exciton decay pathways and the resulting intensity levels. We used this data to propose a model in which multiple on, grey, and off states exist whose equilibrium populations vary with time that give rise to the various intensity levels of single QDs and which depends on shell composition and thickness.
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Affiliation(s)
- Feng Gao
- Department of Chemistry and Biochemistry, University of Arkansas , 345 North Campus Drive, Fayetteville, Arkansas 72701, United States
| | - Pooja Bajwa
- Department of Chemistry and Biochemistry, University of Arkansas , 345 North Campus Drive, Fayetteville, Arkansas 72701, United States
| | - Anh Nguyen
- Department of Chemistry and Biochemistry, University of Arkansas , 345 North Campus Drive, Fayetteville, Arkansas 72701, United States
| | - Colin D Heyes
- Department of Chemistry and Biochemistry, University of Arkansas , 345 North Campus Drive, Fayetteville, Arkansas 72701, United States
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