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Sobhanan J, Anas A, Biju V. Nanomaterials for Fluorescence and Multimodal Bioimaging. CHEM REC 2023; 23:e202200253. [PMID: 36789795 DOI: 10.1002/tcr.202200253] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/27/2023] [Indexed: 02/16/2023]
Abstract
Bioconjugated nanomaterials replace molecular probes in bioanalysis and bioimaging in vitro and in vivo. Nanoparticles of silica, metals, semiconductors, polymers, and supramolecular systems, conjugated with contrast agents and drugs for image-guided (MRI, fluorescence, PET, Raman, SPECT, photodynamic, photothermal, and photoacoustic) therapy infiltrate into preclinical and clinical settings. Small bioactive molecules like peptides, proteins, or DNA conjugated to the surfaces of drugs or probes help us to interface them with cells and tissues. Nevertheless, the toxicity and pharmacokinetics of nanodrugs, nanoprobes, and their components become the clinical barriers, underscoring the significance of developing biocompatible next-generation drugs and contrast agents. This account provides state-of-the-art advancements in the preparation and biological applications of bioconjugated nanomaterials and their molecular, cell, and in vivo applications. It focuses on the preparation, bioimaging, and bioanalytical applications of monomodal and multimodal nanoprobes composed of quantum dots, quantum clusters, iron oxide nanoparticles, and a few rare earth metal ion complexes.
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Affiliation(s)
- Jeladhara Sobhanan
- Graduate School of Environmental Science, Hokkaido University, N10 W5, Sapporo, Hokkaido, 060-0810, Japan.,Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Abdulaziz Anas
- CSIR-National Institute of Oceanography, Regional Centre Kochi, Kerala, 682 018, India
| | - Vasudevanpillai Biju
- Graduate School of Environmental Science, Hokkaido University, N10 W5, Sapporo, Hokkaido, 060-0810, Japan.,Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020, Japan
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Chopra A, Swami A, Sharma R, Devi N, Mittal S, Sharma RK, Wangoo N. Femtomolar detection of staphylococcal enterotoxin 'B' using a fluorescent quantum dot based hybrid Apta-immunosensor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 287:122036. [PMID: 36327805 DOI: 10.1016/j.saa.2022.122036] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 10/10/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Food poisoning is a gastrointestinal illness caused by food-borne enterotoxin produced by the bacterium Staphylococcus aureus. The effective dose of Staphylococcal enterotoxin 'B' (SEB) is estimated to be 0.4 ng/kg of body weight, whereas the 50 % lethal dose is found to be 20 ng/kg of body weight for humans exposed by the inhalation route. The present report highlights the development of a fluorescence resonance energy transfer (FRET) based assay for the detection of Staphylococcal enterotoxin. Highly fluorescent, aqueous quantum dots were synthesized and conjugated with Staphylococcal enterotoxin 'B' specific bioreceptors. SEB specific aptamer and SEB antibody were labeled with fluorescent quantum dots for recognizing and binding two separate epitopes in the SEB. A combination of two probes against different epitopic regions in a homogeneous sandwich assay format enhanced the sensitivity and specificity of SEB detection. In the presence of the enterotoxin, both the aptamer and antibody came in close proximity with each other and FRET was observed. A linear decrease in the fluorescence at 562 nm and a corresponding increase in the signal at 644 nm was observed with increasing concentrations of SEB, when excited at the absorption maximum of quantum dots. The limit of detection for the developed assay obtained was less than 1 ng/ml. The method was employed in apple juice and quantitated using Enzyme-linked Immunosorbent Assay (ELISA). The designed assay was rapid and robust and can be extrapolated as a platform for the detection of various disease-causing agents of biomedical significance.
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Affiliation(s)
- Adity Chopra
- Department of Immunology, Rikshopitalet, Oslo University Hospital, Oslo, Norway
| | - Anuradha Swami
- Department of Applied Sciences, University Institute of Engineering & Technology (U.I.E.T.), Panjab University, Sector-25, Chandigarh 160014, India; Centre for Nanoscience & Nanotechnology, Panjab University, Sector 25, Chandigarh 160014, India
| | - Rohit Sharma
- Centre for Stem Cell and Tissue Engineering, Panjab University, Sector 14, Chandigarh 160014, India
| | - Neha Devi
- Department of Chemistry & Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India
| | - Sherry Mittal
- Department of Chemistry & Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India
| | - Rohit K Sharma
- Department of Chemistry & Centre for Advanced Studies in Chemistry, Panjab University, Sector-14, Chandigarh 160014, India
| | - Nishima Wangoo
- Department of Applied Sciences, University Institute of Engineering & Technology (U.I.E.T.), Panjab University, Sector-25, Chandigarh 160014, India.
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Sannaikar M, Inamdar (Doddamani) LS, Inamdar SR. Interaction between human serum albumin and toxic free InP/ZnS QDs using multi-spectroscopic study: An excellent alternate to heavy metal based QDs. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.02.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Thomas EM, Ghimire S, Kohara R, Anil AN, Yuyama KI, Takano Y, Thomas KG, Biju V. Blinking Suppression in Highly Excited CdSe/ZnS Quantum Dots by Electron Transfer under Large Positive Gibbs (Free) Energy Change. ACS NANO 2018; 12:9060-9069. [PMID: 30103604 DOI: 10.1021/acsnano.8b03010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Semiconductor quantum dots with stable photoluminescence are necessary for next generation optoelectronic and photovoltaic devices. Photoluminescence intensity fluctuations of cadmium and lead chalcogenide quantum dots have been extensively investigated since the first observation of blinking in CdSe nanocrystals in 1996. In a quantum dot, blinking originates from stochastic photocharging, nonradiative Auger recombination, and delayed neutralization. So far, blinking is suppressed by defect passivation, electron transfer, and shell preparation, but without any deep insight into free energy change of electron transfer. We report real-time detection of significant blinking suppression for CdSe/ZnS quantum dots exposed to N, N-dimethylaniline, which is accompanied by a considerable increase in the time-averaged photoluminescence intensity of quantum dots. Although the Gibbs (free) energy change (Δ Get = +2.24 eV), which is estimated electrochemically and from density functional theory calculations, is unfavorable for electron transfer from N, N-dimethylaniline to a quantum dot in the minimally excited (band-edge) state, electron transfer is obvious when a quantum dot is highly excited. Nonetheless, Δ Get crosses from the positive to negative scale as the solvent dielectric constant exceeds 5, favoring electron transfer from N, N-dimethylaniline to a quantum dot excited to the band-edge state. Based on single-molecule photoluminescence and ensemble electron transfer studies, we assign blinking suppression to the transfer of an electron from N, N-dimethylaniline to the hot hole state of a quantum dot. In addition to blinking suppression by electron transfer, complete removal of blinking is limited by short-living OFF states induced by the negative trion.
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Affiliation(s)
- Elizabeth Mariam Thomas
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- School of Chemistry , Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM) , Thiruvananthapuram 695551 , India
| | - Sushant Ghimire
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
| | - Reiko Kohara
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
| | - Ajith Nair Anil
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
| | - Ken-Ichi Yuyama
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
| | - Yuta Takano
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
| | - K George Thomas
- School of Chemistry , Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM) , Thiruvananthapuram 695551 , India
| | - Vasudevanpillai Biju
- Research Institute for Electronic Science , Hokkaido University , Sapporo , Hokkaido 001-0020 , Japan
- Graduate School of Environmental Science , Hokkaido University , Sapporo , Hokkaido 060-0810 , Japan
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Ghimire S, Biju V. Relations of exciton dynamics in quantum dots to photoluminescence, lasing, and energy harvesting. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2018. [DOI: 10.1016/j.jphotochemrev.2018.01.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sannaikar MS, Inamdar LS, Pujar GH, Wari MN, Balasinor NH, Inamdar SR. Comprehensive study of interaction between biocompatible PEG-InP/ZnS QDs and bovine serum albumin. LUMINESCENCE 2017; 33:495-504. [DOI: 10.1002/bio.3438] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/27/2017] [Accepted: 11/13/2017] [Indexed: 11/07/2022]
Affiliation(s)
- M. S. Sannaikar
- Laser Spectroscopy Programme and UGC-CPEPA, Department of Physics; Karnatak University; Dharwad Karnataka India
| | - Laxmi S. Inamdar
- Molecular Endocrinology, Reproduction and Development Laboratory, Department of Zoology; Karnatak University; Dharwad Karnataka India
| | - G. H. Pujar
- Laser Spectroscopy Programme and UGC-CPEPA, Department of Physics; Karnatak University; Dharwad Karnataka India
| | - M. N. Wari
- Laser Spectroscopy Programme and UGC-CPEPA, Department of Physics; Karnatak University; Dharwad Karnataka India
| | - Nafisa H. Balasinor
- Neuroendocrinology Department; National Institute for Research in Reproductive Health; Parel Mumbai India
| | - S. R. Inamdar
- Laser Spectroscopy Programme and UGC-CPEPA, Department of Physics; Karnatak University; Dharwad Karnataka India
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Mirnajafizadeh F, Ramsey D, McAlpine S, Wang F, Reece P, Stride JA. Hydrothermal synthesis of highly luminescent blue-emitting ZnSe(S) quantum dots exhibiting low toxicity. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 64:167-172. [PMID: 27127041 DOI: 10.1016/j.msec.2016.03.061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 03/14/2016] [Accepted: 03/21/2016] [Indexed: 12/31/2022]
Abstract
Highly luminescent quantum dots (QDs) that emit in the visible spectrum are of interest to a number of imaging technologies, not least that of biological samples. One issue that hinders the application of luminescent markers in biology is the potential toxicity of the fluorophore. Here we show that hydrothermally synthesized ZnSe(S) QDs have low cytotoxicity to both human colorectal carcinoma cells (HCT-116) and human skin fibroblast cells (WS1). The QDs exhibited a high degree of crystallinity, with a strong blue photoluminescence at up to 29% quantum yield relative to 4',6-diamidino-2-phenylindole (DAPI) without post-synthetic UV-irradiation. Confocal microscopy images obtained of HCT-116 cells after incubation with the QDs highlighted the stability of the particles in cell media. Cytotoxicity studies showed that both HCT-116 and WS1 cells retain 100% viability after treatment with the QDs at concentrations up to 0.5g/L, which makes them of potential use in biological imaging applications.
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Affiliation(s)
| | - Deborah Ramsey
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Shelli McAlpine
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Fan Wang
- School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - Peter Reece
- School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
| | - John Arron Stride
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia; Bragg Institute, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia.
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Rama Raju GS, Pavitra E, Nagaraju G, Guan XY, Yu JS. UV-A and UV-B excitation region broadened novel green color-emitting CaGd2ZnO5:Tb3+ nanophosphors. RSC Adv 2015. [DOI: 10.1039/c4ra15376f] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CaGd2ZnO5:Tb3+ nanophosphors showed the broadened excitation region as compared to Y2O3:Tb3+ and Gd2O3:Tb3+ phosphors, which covered almost the entire UV-B and UV-A regions.
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Affiliation(s)
- G. Seeta Rama Raju
- Department of Electronics and Radio Engineering
- Institute for Laser Engineering
- Kyung Hee University
- Yongin-si
- Republic of Korea
| | - E. Pavitra
- Department of Electronics and Radio Engineering
- Institute for Laser Engineering
- Kyung Hee University
- Yongin-si
- Republic of Korea
| | - Goli Nagaraju
- Department of Electronics and Radio Engineering
- Institute for Laser Engineering
- Kyung Hee University
- Yongin-si
- Republic of Korea
| | - Xiang-Yu Guan
- Department of Electronics and Radio Engineering
- Institute for Laser Engineering
- Kyung Hee University
- Yongin-si
- Republic of Korea
| | - Jae Su Yu
- Department of Electronics and Radio Engineering
- Institute for Laser Engineering
- Kyung Hee University
- Yongin-si
- Republic of Korea
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10
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Grzyb J, Kalwarczyk E, Worch R. Photoreduction of natural redox proteins by CdTe quantum dots is size-tunable and conjugation-independent. RSC Adv 2015. [DOI: 10.1039/c5ra02900g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Colloidal CdTe quantum dots may photoreduce both heme and iron–sulfur cluster containing proteins. Reduction level may be tuned by choosing different size of nanocrystals.
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11
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Yadav N, Kumar S, Dhar R. Cadmium selenide quantum dots for the amelioration of the properties of a room temperature discotic liquid crystalline material. RSC Adv 2015. [DOI: 10.1039/c5ra17401e] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The effect of cadmium selenide quantum dots on a room temperature discotic liquid crystalline material has been studied.
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Affiliation(s)
- Neelam Yadav
- Centre of Material Sciences
- University of Allahabad
- Allahabad 211002
- India
| | | | - Ravindra Dhar
- Centre of Material Sciences
- University of Allahabad
- Allahabad 211002
- India
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12
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Chiang WY, Okuhata T, Usman A, Tamai N, Masuhara H. Efficient Optical Trapping of CdTe Quantum Dots by Femtosecond Laser Pulses. J Phys Chem B 2014; 118:14010-6. [DOI: 10.1021/jp502524f] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Wei-Yi Chiang
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu 30010, Taiwan
| | - Tomoki Okuhata
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda 669-1337, Japan
| | - Anwar Usman
- Solar
and Photovoltaic Engineering Research Center, Division of Physical
Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Naoto Tamai
- Department
of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda 669-1337, Japan
| | - Hiroshi Masuhara
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta Hsueh Rd., Hsinchu 30010, Taiwan
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Shibu ES, Hamada M, Nakanishi S, Wakida SI, Biju V. Photoluminescence of CdSe and CdSe/ZnS quantum dots: Modifications for making the invisible visible at ensemble and single-molecule levels. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.10.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Wheeler DA, Zhang JZ. Exciton dynamics in semiconductor nanocrystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:2878-2896. [PMID: 23625792 DOI: 10.1002/adma.201300362] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Indexed: 06/02/2023]
Abstract
This review article provides an overview of recent advances in the study and understanding of dynamics of excitons in semiconductor nanocrystals (NCs) or quantum dots (QDs). Emphasis is placed on the relationship between exciton dynamics and optical properties, both linear and nonlinear. We also focus on the unique aspects of exciton dynamics in semiconductor NCs as compared to those in bulk crystals. Various experimental techniques for probing exciton dynamics, particularly time-resolved laser methods, are reviewed. Relevant models and computational studies are also briefly presented. By comparing different materials systems, a unifying picture is proposed to account for the major dynamic features of excitons in semiconductor QDs. While the specific dynamic processes involved are material-dependent, key processes can be identified for all the materials that include electronic dephasing, intraband relaxation, trapping, and interband recombination of free and trapped charge carriers (electron and hole). Exciton dynamics play a critical role in the fundamental properties and functionalities of nanomaterials of interest for a variety of applications including optical detectors, solar energy conversion, lasers, and sensors. A better understanding of exciton dynamics in nanomaterials is thus important both fundamentally and technologically.
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Affiliation(s)
- Damon A Wheeler
- Department of Chemistry & Biochemistry, University of California, Santa Cruz, CA 95064 USA, Fax: (831) 459-3776
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Omogo B, Aldana JF, Heyes CD. Radiative and Non-Radiative Lifetime Engineering of Quantum Dots in Multiple Solvents by Surface Atom Stoichiometry and Ligands. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2013; 117:2317-2327. [PMID: 23543893 PMCID: PMC3610600 DOI: 10.1021/jp309368q] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
CdTe quantum dots have unique characteristics that are promising for applications in photoluminescence, photovoltaics or optoelectronics. However, wide variations of the reported quantum yields exist and the influence of ligand-surface interactions that are expected to control the excited state relaxation processes remains unknown. It is important to thoroughly understand the fundamental principles underlying these relaxation processes to tailor the QDs properties to their application. Here, we systematically investigate the roles of the surface atoms, ligand functional groups and solvent on the radiative and non-radiative relaxation rates. Combining a systematic synthetic approach with X-ray photoelectron, quantitative FT-IR and time-resolved visible spectroscopies, we find that CdTe QDs can be engineered with average radiative lifetimes ranging from nanoseconds up to microseconds. The non-radiative lifetimes are anticorrelated to the radiative lifetimes, although they show much less variation. The density, nature and orientation of the ligand functional groups and the dielectric constant of the solvent play major roles in determining charge carrier trapping and excitonic relaxation pathways. These results are used to propose a coupled dependence between hole-trapping on Te atoms and strong ligand coupling, primarily via Cd atoms, that can be used to engineer both the radiative and non-radiative lifetimes.
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Abstract
The use of CdTe quantum dots (QDs) as fluorescent probes for detection of copper(II) in seawater was evaluated, and the relationship between the size of CdTe QDs and fluorescent response in seawater was investigated. The fluorescence intensity of CdTe QDs was quenched linearly as the concentration of copper(II) increased, and the quenching efficiency increased as the size of the CdTe QDs decreased. The smaller CdTe QDs (emission peak at 518 nm, average diameter of ~2.1 nm) achieved a detection limit of copper(II) of 0.48 μg L−1 under optimal experimental conditions. No significant influence was found for pH in the range from 7.0 to 9.0 in seawater. In contrast, the emission maxima of the CdTe QDs exhibited a slight red shift and the intensity of fluorescence decreased significantly as salinity was increased. Based on the performance of CdTe QDs in this study, small CdTe QDs display enormous potential for detection of copper(II) in seawater.
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Mandal A, Tamai N. Luminescence enhancement of water soluble CdTe quantum dots by proper surface modification with ethylene diamine. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.03.086] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Sagarzazu G, Kobayashi Y, Murase N, Yang P, Tamai N. Auger recombination dynamics in hybrid silica-coated CdTe nanocrystals. Phys Chem Chem Phys 2011; 13:3227-30. [DOI: 10.1039/c0cp01957g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Yang Z, Liu Y, He X, Wen Y, Yang Y. Competition between surface trapping and nonradiative energy transfer to gold nanofilm. JOURNAL OF APPLIED PHYSICS 2010; 108:94309. [PMID: 21124724 PMCID: PMC2994926 DOI: 10.1063/1.3503518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 09/15/2010] [Indexed: 05/30/2023]
Abstract
Nonradiative resonant energy transfer from CdSeS quantum dot to gold nanofilm was investigated by taking nanosecond and picosecond time resolved photoluminescence measurements. Surface plasma resonant absorption peak of gold nanofilm was adjusted to meet the near resonant conditions with the fluorescence peak of quantum dot by changing the thickness. Surface trapping state was proved to be the origin of the long lifetime component by comparing fresh and eight months aged quantum dot. It was observed that the excitonic state lifetime of the quantum dots was reduced by nonradiative resonant energy transfer to gold nanofilm. Nonradiative resonant energy transfer time, which was comparable with the surface trapping time, was calculated based on the data of picosecond photoluminescence measurements. No nonradiative energy transfer from surface trapping state to gold nanofilm, thus the lifetime of surface trapping state was not affected obviously. It is suggested that in the assembly combined with quantum dot and gold nanostructure, nonradiative energy transfer will occur after the population of excitonic state, and compete with surface trapping process. The interactions between surface trapping state and gold nanoflim were not exhibited.
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Jin S, Hsiang JC, Zhu H, Song N, Dickson RM, Lian T. Correlated Single Quantum Dot Blinking and Interfacial Electron Transfer Dynamics. Chem Sci 2010; 1:519-526. [PMID: 21915369 PMCID: PMC3170728 DOI: 10.1039/c0sc00334d] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The electron transfer (ET) dynamics from core/multi-shell (CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML)) quantum dots (QDs) to adsorbed Fluorescein (F27) molecules have been studied by single particle spectroscopy to probe the relationship between single QD interfacial electron transfer and blinking dynamics. Electron transfer from the QD to F27 and the subsequent recombination were directly observed by ensemble-averaged transient absorption spectroscopy. Single QD-F27 complexes show correlated fluctuation of fluorescence intensity and lifetime, similar to those observed in free QDs. With increasing ET rate (controlled by F27-to-QD ratio), the lifetime of on states decreases and relative contribution of off states increases. It was shown that ET is active for QDs in on states, the excited state lifetime of which reflects the ET rate, whereas in the off state QD excitons decay by Auger relaxation and ET is not a competitive quenching pathway. Thus, the blinking dynamics of single QDs modulate their interfacial ET activity. Furthermore, interfacial ET provides an additional pathway for generating off states, leading to correlated single QD interfacial ET and blinking dynamics in QD-acceptor complexes. Because blinking is a general phenomenon of single QDs, it appears that the correlated interfacial ET and blinking and the resulting intermittent ET activity are general phenomena for single QDs.
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Affiliation(s)
- Shengye Jin
- Department of Chemistry, Emory University, Atlanta, GA, 30322
| | - Jung-Cheng Hsiang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400
| | - Haiming Zhu
- Department of Chemistry, Emory University, Atlanta, GA, 30322
| | - Nianhui Song
- Department of Chemistry, Emory University, Atlanta, GA, 30322
| | - Robert M. Dickson
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400
| | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, GA, 30322
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Liu YF, Yu JS. In situ synthesis of highly luminescent glutathione-capped CdTe/ZnS quantum dots with biocompatibility. J Colloid Interface Sci 2010; 351:1-9. [PMID: 20719328 DOI: 10.1016/j.jcis.2010.07.047] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 07/01/2010] [Accepted: 07/17/2010] [Indexed: 11/17/2022]
Abstract
This paper focuses on the in situ synthesis of novel CdTe/ZnS core-shell quantum dots (QDs) in aqueous solution. Glutathione (GSH) was used as both capping reagent and sulfur source for in situ growth of ZnS shell on the CdTe core QDs. The maximum emission wavelengths of the prepared CdTe/ZnS QDs can be simply tuned from 569 nm to 630 nm. The PL quantum yield of CdTe/ZnS QDs synthesized is up to 84%, larger than the original CdTe QDs by around 1.7 times. The PL lifetime results reveal a triexponential decay model of exciton and trap radiation behavior. The average exciton lifetime at room temperature is 17.1 ns for CdTe (2.8 nm) and 27.4 ns for CdTe/ZnS (3.7 nm), respectively. When the solution of QDs is dialyzed for 3 h, 1.17 ppm of Cd(2+) is released from CdTe QDs and 0.35 ppm is released from CdTe/ZnS. At the dose of 120 microg/ml QDs, 9.5% of hemolysis was induced by CdTe QDs and 3.9% was induced by CdTe/ZnS QDs. These results indicate that the synthesized glutathione-capped CdTe/ZnS QDs are of less toxicity and better biocompatibility, so that are attractive for use in biological detection and related fields.
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Affiliation(s)
- Ying-Fan Liu
- Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China
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Jin S, Song N, Lian T. Suppressed blinking dynamics of single QDs on ITO. ACS NANO 2010; 4:1545-1552. [PMID: 20170100 DOI: 10.1021/nn901808f] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The exciton quenching dynamics of single CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML) core/multishell QDs adsorbed on glass, In2O3, and ITO have been compared. Single QDs on In2O3 show shorter fluorescence lifetimes and higher blinking frequencies than those on glass because of interfacial electron transfer from QDs to In2O3. Compared to glass and In2O3, single QDs on ITO show suppressed blinking activity as well as reduced fluorescence lifetimes. For QDs in contact with the n-doped ITO, the equilibration of their Fermi levels leads to the formation of negatively charged QDs. In these negatively charged QDs, the off states are suppressed because of the effective removal of the valence band holes, and their fluorescence lifetimes are shortened because of exciton Auger recombination and hole transfer processes involving the additional electrons. This study shows that the blinking of single QDs can be effectively suppressed on the surface of ITO. This phenomenon may also be observable for other QDs and on different n-doped semiconductors.
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Affiliation(s)
- Shengye Jin
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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Wang CL, Fang M, Xu SH, Cui YP. Salts-based size-selective precipitation: toward mass precipitation of aqueous nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:633-638. [PMID: 20027995 DOI: 10.1021/la903986v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Purification is a necessary step before the application of nanocrystals (NCs), since the excess matter in nanoparticles solution usually causes a disadvantage to their subsequent coupling or assembling with other materials. In this work, a novel salts-based precipitation technique is originally developed for the precipitation and size-selective precipitation of aqueous NCs. Simply by addition of salts, NCs can be precipitated from the solution. After decantation of the supernatant solution, the precipitates can be dispersed in water again. By means of adjusting the addition amount of salt, size-selective precipitation of aqueous NCs can be achieved. Namely, the NCs with large size are precipitated preferentially, leaving small NCs in solution. Compared with the traditional nonsolvents-based precipitation technique, the current one is simpler and more rapid due to the avoidance of condensation and heating manipulations used in the traditional precipitation process. Moreover, the salts-based precipitation technique was generally available for the precipitation of aqueous nanoparticles, no matter if there were semiconductor NCs or metal nanoparticles. Simultaneously, the cost of the current method is also much lower than that of the traditional nonsolvents-based precipitation technique, making it applicable for mass purification of aqueous NCs.
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Affiliation(s)
- Chun-Lei Wang
- Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, People's Republic of China
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Kinkead B, Hegmann T. Effects of size, capping agent, and concentration of CdSe and CdTequantum dots doped into a nematic liquid crystal on the optical and electro-optic properties of the final colloidal liquid crystal mixture. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b911641a] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jin S, Lian T. Electron transfer dynamics from single CdSe/ZnS quantum dots to TiO2 nanoparticles. NANO LETTERS 2009; 9:2448-2454. [PMID: 19453136 DOI: 10.1021/nl9011744] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Electron-transfer dynamics from single CdSe/ZnS (core/shell) QDs to TiO(2) nanoparticles were studied. Single QDs on TiO(2) showed pronounced and correlated fluctuations of fluorescence intensity and lifetime. Compared to QDs on glass, the presence of the interparticle ET pathway on TiO(2) led to smaller on-state and larger off-state probability densities, as well as a shortened lifetime of the on-state. The average electron transfer rate from CdSe/ZnS to TiO(2) was estimated to be 3.2 x 10(7) s(-1).
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Affiliation(s)
- Shengye Jin
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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Biju V, Itoh T, Anas A, Sujith A, Ishikawa M. Semiconductor quantum dots and metal nanoparticles: syntheses, optical properties, and biological applications. Anal Bioanal Chem 2008; 391:2469-95. [PMID: 18548237 DOI: 10.1007/s00216-008-2185-7] [Citation(s) in RCA: 422] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 04/25/2008] [Accepted: 05/13/2008] [Indexed: 12/12/2022]
Abstract
We review the syntheses, optical properties, and biological applications of cadmium selenide (CdSe) and cadmium selenide-zinc sulfide (CdSe-ZnS) quantum dots (QDs) and gold (Au) and silver (Ag) nanoparticles (NPs). Specifically, we selected the syntheses of QDs and Au and Ag NPs in aqueous and organic phases, size- and shape-dependent photoluminescence (PL) of QDs and plasmon of metal NPs, and their bioimaging applications. The PL properties of QDs are discussed with reference to their band gap structure and various electronic transitions, relations of PL and photoactivated PL with surface defects, and blinking of single QDs. Optical properties of Ag and Au NPs are discussed with reference to their size- and shape-dependent surface plasmon bands, electron dynamics and relaxation, and surface-enhanced Raman scattering (SERS). The bioimaging applications are discussed with reference to in vitro and in vivo imaging of live cells, and in vivo imaging of cancers, tumor vasculature, and lymph nodes. Other aspects of the review are in vivo deep tissue imaging, multiphoton excitation, NIR fluorescence and SERS imaging, and toxic effects of NPs and their clearance from the body.
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Affiliation(s)
- Vasudevanpillai Biju
- Nano-Bioanalysis Team, Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa, 761-0395, Japan.
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Tracking single quantum dot and its spectrum in free solution with controllable thermal diffusion suppression. Anal Biochem 2008; 377:176-81. [DOI: 10.1016/j.ab.2008.03.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Revised: 03/09/2008] [Accepted: 03/12/2008] [Indexed: 11/23/2022]
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