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Jang T, Lee S, Pang Y. Anomalous proton transfer of a photoacid HPTS in nonaqueous reverse micelles. Phys Chem Chem Phys 2024; 26:11283-11294. [PMID: 38456549 DOI: 10.1039/d3cp05710k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The proton transfer reaction is one of the fundamental chemical reactions where the reaction dynamics strongly depend on solvent properties such as acidity or basicity. A photoacid 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) shows a sharp decrease of pKa (7.7 → 0.5) upon photoexcitation, and the excited-state proton transfer (ESPT) occurs with ultrafast time constants of 2.5 and 89 ps in bulk aqueous solution. However, the two-step proton transfers via the contact ion pair formation and the proton diffusion are strongly limited inside the nanopools of reverse micelles (RMs). The confinement in small RMs strongly impeded the proton transfer reactions. In this work, we report the ESPT of HPTS confined in methanol-in-oil RMs by steady-state and time-resolved electronic spectroscopy. Interestingly, HPTS shows substantial deprotonation in the excited state only in small RMs, while the ESPT of HPTS does not occur in bulk methanol solution due to the low basicity of aliphatic alcohols. The kinetic analysis of time-resolved fluorescence and transient absorption measurements will compare the proton transfer dynamics of HPTS in the water-in-oil and methanol-in-oil RMs. The ESPT of photoacids, especially in the nonaqueous RMs, can be crucial in understanding many important chemical reactions involving proton transfer in the confined environments of cells and membranes.
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Affiliation(s)
- Taehyung Jang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Sebok Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
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2
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Xie B, Meng Q, Yu H, Shen K, Cheng Y, Dong C, Zhou HB. Estrogen receptor β-targeted hypoxia-responsive near-infrared fluorescence probes for prostate cancer study. Eur J Med Chem 2022; 238:114506. [DOI: 10.1016/j.ejmech.2022.114506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 12/01/2022]
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3
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Lee D, Song J, Song G, Pang Y. Metal-enhanced fluorescence of dyes with quadrupole surface plasmon resonance of silver nanoparticles. NANOSCALE ADVANCES 2022; 4:2794-2805. [PMID: 36132004 PMCID: PMC9418669 DOI: 10.1039/d1na00837d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 05/03/2022] [Indexed: 05/29/2023]
Abstract
Silver colloidal films (SCFs) composed of homogeneous 60-220 nm silver nanoparticles were synthesized for optimal fluorescence enhancement of chromophores with the dipole and quadrupole surface plasmons. The fluorescence enhancements with the SCFs of three chromophores, 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran, 4-dimethylamino-4'-nitrobiphenyl, and coumarin 343 whose emission spectra are centered distinctively in the 470-560 nm wavelength range were compared. Fluorescence enhancements and lifetime changes were investigated via time-resolved fluorescence spectroscopy. The spectral overlap between the chromophore's emission and the dipole or quadrupole surface plasmon resonance (SPR) bands determined the fluorescence enhancements with the SCFs. The dipole and quadrupole SPR bands both appeared to provide effective fluorescence enhancements of chromophores. This knowledge allows researchers to develop sensitive fluorescence sensors by combining nanoparticles with optimal dipole or quadrupole SPR bands in order to achieve fluorescence enhancement of a specific chromophore. The emission dynamics measurements with the SCFs were combined with the finite-difference time-domain simulation results for the local electric fields around the silver nanoparticles to enable discussion of metal-enhanced fluorescence mechanisms, including excitation and emission enhancements.
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Affiliation(s)
- Daedu Lee
- Department of Chemistry, Gwangju Institute of Science and Technology 123 Cheomdangwagi-ro, Buk-gu Gwangju 61005 Republic of Korea
| | - Junghyun Song
- Department of Chemistry, Gwangju Institute of Science and Technology 123 Cheomdangwagi-ro, Buk-gu Gwangju 61005 Republic of Korea
| | - Gyounghyun Song
- Department of Chemistry, Gwangju Institute of Science and Technology 123 Cheomdangwagi-ro, Buk-gu Gwangju 61005 Republic of Korea
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology 123 Cheomdangwagi-ro, Buk-gu Gwangju 61005 Republic of Korea
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4
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Twisted intramolecular charge transfer of nitroaromatic push-pull chromophores. Sci Rep 2022; 12:6557. [PMID: 35449231 PMCID: PMC9023442 DOI: 10.1038/s41598-022-10565-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/11/2022] [Indexed: 12/02/2022] Open
Abstract
The structural changes during the intramolecular charge transfer (ICT) of nitroaromatic chromophores, 4-dimethylamino-4′-nitrobiphenyl (DNBP) and 4-dimethylamino-4′-nitrostilbene (DNS) were investigated by femtosecond stimulated Raman spectroscopy (FSRS) with both high spectral and temporal resolutions. The kinetically resolved Raman spectra of DNBP and DNS in the locally-excited and charge-transferred states of the S1 state appear distinct, especially in the skeletal vibrational modes of biphenyl and stilbene including ν8a and νC=C. The ν8a of two phenyls and the νC=C of the central ethylene group (only for stilbene), which are strongly coupled in the planar geometries, are broken with the twist of nitrophenyl group with the ICT. Time-resolved vibrational spectroscopy measurements and the time-dependent density functional theory simulations support the ultrafast ICT dynamics of 220–480 fs with the twist of nitrophenyl group occurring in the S1 state of the nitroaromatic chromophores. While the ICT of DNBP occurs via a barrier-less pathway, the ICT coordinates of DNS are strongly coupled to several low-frequency out-of-phase deformation modes relevant to the twist of the nitrophenyl group.
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5
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Lee S, Jen M, Lee G, Jang T, Pang Y. Intramolecular charge transfer of a push-pull chromophore with restricted internal rotation of an electron donor. Phys Chem Chem Phys 2022; 24:5794-5802. [PMID: 35195633 DOI: 10.1039/d1cp05541k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Intramolecular charge transfer (ICT) of 4-(dicyanomethylene)-2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran (LD688) in DMSO solution was investigated by femtosecond stimulated Raman spectroscopy (FSRS) with 403 nm excitation. The molecular structure of LD688 is similar to that of a well-known push-pull chromophore, 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM), except that the internal rotation of the electron-donating dimethylamino group is restricted with the introduction of the julolidine moiety. Upon photo-excitation, LD688 shows an ultrafast (1.0 ps) ICT followed by the vibrational relaxation (3-8 ps) in the charge-transfer (CT) state. Two distinct Raman spectra of LD688 in the locally excited (LE) and CT state of the S1 state were retrieved from FSRS measurements. Based on the time-dependent density functional theory (TDDFT) simulations, a "twisted" julolidine geometry of LD688 was proposed for the ICT state, which was further confirmed in comparison to the spectral changes of several push-pull chromophores with the π-conjugated backbone of stilbene, biphenyl, styrylpyran, styrylpyridinium, and styrene in terms of the skeletal vibrational modes of ν19b,py, νCC,ph, and νCN.
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Affiliation(s)
- Sebok Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Myungsam Jen
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Gisang Lee
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Taehyung Jang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
| | - Yoonsoo Pang
- Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
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6
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Meng Q, Xie B, Yu H, Shen K, Deng X, Zhou HB, Dong C. Estrogen Receptor β-Targeted Near-Infrared Inherently Fluorescent Probe: A Potent Tool for Estrogen Receptor β Research. ACS Sens 2022; 7:109-115. [PMID: 34914372 DOI: 10.1021/acssensors.1c01771] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Estrogen receptor β (ERβ) is associated with many diseases, and ERβ probes can help to reveal the complex role of ERβ and promote the development of ERβ-targeted therapy. Herein, we designed and synthesized the first ERβ-targeted near-infrared (NIR) inherently fluorescent probe P5, which showed the advantages of high ERβ selectivity, good optical properties, and excellent ERβ imaging capability in living cells. The probe was successfully utilized to explore ERβ motion characteristic, and for the first time, the diffusion coefficient of ERβ was obtained. Moreover, P5 was also successfully applied to the in vivo imaging of ERβ in the prostate cancer mice model. Therefore, this ERβ-targeted NIR probe might be employed as a potential tool for the research of ERβ and related diseases.
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Affiliation(s)
- Qiuyu Meng
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Baohua Xie
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Huiguang Yu
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Kang Shen
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Xiangping Deng
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Hai-Bing Zhou
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chune Dong
- State Key Laboratory of Virology, Frontier Science Center for Immunology and Metabolism, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan University), Ministry of Education, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
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7
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Thomas EM, Cortes CL, Paul L, Gray S, Thomas KG. Combined Effects of Emitter-Emitter and Emitter-Plasmonic Surface Separations Dictate Photoluminescence Enhancement in Plasmonic Field. Phys Chem Chem Phys 2022; 24:17250-17262. [DOI: 10.1039/d2cp01681h] [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
The brightness of an emitter can be enhanced by metal-enhanced fluorescence, wherein the excitonic dipole couples with the electromagnetic field of the surface plasmon. Herein, we experimentally map the landscape...
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8
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Burris AJ, Cheng Q. Plasmon-Enhanced Fluorescence in Electrospun Nanofibers of Polydiacetylenes Infused with Silver Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14920-14929. [PMID: 34902973 DOI: 10.1021/acs.langmuir.1c02805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A hybrid computational and experimental approach was employed toward the rational design of a silver nanoparticle (AgNP)/polydiacetylene (PDA) metal-enhanced fluorophore (MEF) ensemble system contained within a poly(ethylene oxide) (PEO) electrospun nanofiber matrix for creation of high-performance sensors. Simulations based on Mie theory and finite-difference time domain (FDTD) algorithms were performed to understand and optimize spectral overlap between the AgNP localized surface plasmon resonance and the absorbance and emission spectra of PDA, a supramolecular polymer fluorophore. A series of AgNPs of varied sizes were investigated for fluorescence enhancement capability, and an optimal size of 134 nm in diameter was chosen for synthesis and incorporation into the electrospun nanofibers of a PDA/PEO composite for experimental characterization and confirmation. Results on individual nanofibers indicated a clear metal-enhanced fluorescence effect, and a 4.6-fold enhancement over neat PDA/PEO fluorescent nanofibers was observed. The nanofiber/nanoparticle/MEF ensemble system offers new avenues for generating effective sensing devices with polymeric fluorophores using a straightforward incorporation approach.
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Affiliation(s)
- Andrew J Burris
- Department of Chemistry, University of California, Riverside, California 92521, United States
| | - Quan Cheng
- Department of Chemistry, University of California, Riverside, California 92521, United States
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9
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Lee D, Song G, Pang Y. Composite silver nanosurfaces of dipole and quadrupole surface plasmon resonances for fluorescence enhancements. B KOREAN CHEM SOC 2021. [DOI: 10.1002/bkcs.12428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Daedu Lee
- Department of Chemistry Gwangju Institute of Science and Technology Gwangju Korea
| | - Gyounghyun Song
- Department of Chemistry Gwangju Institute of Science and Technology Gwangju Korea
| | - Yoonsoo Pang
- Department of Chemistry Gwangju Institute of Science and Technology Gwangju Korea
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10
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Okolo CA, Kounatidis I, Groen J, Nahas KL, Balint S, Fish TM, Koronfel MA, Cortajarena AL, Dobbie IM, Pereiro E, Harkiolaki M. Sample preparation strategies for efficient correlation of 3D SIM and soft X-ray tomography data at cryogenic temperatures. Nat Protoc 2021; 16:2851-2885. [PMID: 33990802 DOI: 10.1038/s41596-021-00522-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 02/09/2021] [Indexed: 02/07/2023]
Abstract
3D correlative microscopy methods have revolutionized biomedical research, allowing the acquisition of multidimensional information to gain an in-depth understanding of biological systems. With the advent of relevant cryo-preservation methods, correlative imaging of cryogenically preserved samples has led to nanometer resolution imaging (2-50 nm) under harsh imaging regimes such as electron and soft X-ray tomography. These methods have now been combined with conventional and super-resolution fluorescence imaging at cryogenic temperatures to augment information content from a given sample, resulting in the immediate requirement for protocols that facilitate hassle-free, unambiguous cross-correlation between microscopes. We present here sample preparation strategies and a direct comparison of different working fiducialization regimes that facilitate 3D correlation of cryo-structured illumination microscopy and cryo-soft X-ray tomography. Our protocol has been tested at two synchrotron beamlines (B24 at Diamond Light Source in the UK and BL09 Mistral at ALBA in Spain) and has led to the development of a decision aid that facilitates experimental design with the strategic use of markers based on project requirements. This protocol takes between 1.5 h and 3.5 d to complete, depending on the cell populations used (adherent cells may require several days to grow on sample carriers).
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Affiliation(s)
- Chidinma A Okolo
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Ilias Kounatidis
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | | | - Kamal L Nahas
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.,Division of Virology, Department of Pathology, University of Cambridge, Cambridge, UK
| | - Stefan Balint
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
| | - Thomas M Fish
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Mohamed A Koronfel
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK
| | - Aitziber L Cortajarena
- Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Donostia San Sebastián, Spain.,Ikerbasque, Basque Foundation for Science, Bilbao, Spain
| | - Ian M Dobbie
- Micron Advanced Imaging Consortium, Department of Biochemistry, University of Oxford, Oxford, UK
| | - Eva Pereiro
- Beamline 09-MISTRAL, ALBA Synchrotron, Barcelona, Spain
| | - Maria Harkiolaki
- Beamline B24, Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.
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11
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Ćwik M, Sulowska K, Buczyńska D, Roźniecka E, Domagalska M, Maćkowski S, Niedziółka-Jönsson J. Controlling plasmon propagation and enhancement via reducing agent in wet chemistry synthesized silver nanowires. OPTICS EXPRESS 2021; 29:8834-8845. [PMID: 33820325 DOI: 10.1364/oe.412903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Silver nanowires with varying diameters and submillimeter lengths were obtained by changing a reducing agent used during hydrothermal synthesis. The control over the nanowire diameter turns out to play a critical role in determining their plasmonic properties, including fluorescence enhancement and surface plasmon polariton propagation. Advanced fluorescence imaging of hybrid nanostructures assembled of silver nanowires and photoactive proteins indicates longer propagation lengths for nanowires featuring larger diameters. At the same time, with increasing diameter of the nanowires, we measure a substantial reduction of fluorescence enhancement. The results point at possible ways to control the influence of plasmon excitations in silver nanowires by tuning their morphology.
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12
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Twisted Intramolecular Charge Transfer State of a "Push-Pull" Emitter. Int J Mol Sci 2020; 21:ijms21217999. [PMID: 33121185 PMCID: PMC7662227 DOI: 10.3390/ijms21217999] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 11/17/2022] Open
Abstract
The excited state Raman spectra of 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) in the locally-excited (LE) and the intramolecular charge transfer (ICT) states have been separately measured by time-resolved stimulated Raman spectroscopy. In a polar dimethylsulfoxide solution, the ultrafast ICT of DCM with a time constant of 1.0 ps was observed in addition to the vibrational relaxation in the ICT state of 4–7 ps. On the other hand, the energy of the ICT state of DCM becomes higher than that of the LE state in a less polar chloroform solution, where the initially-photoexcited ICT state with the LE state shows the ultrafast internal conversion to the LE state with a time constant of 300 fs. The excited-state Raman spectra of the LE and ICT state of DCM showed several major vibrational modes of DCM in the LE and ICT conformer states coexisting in the excited state. Comparing to the time-dependent density functional theory simulations and the experimental results of similar push-pull type molecules, a twisted geometry of the dimethylamino group is suggested for the structure of DCM in the S1/ICT state.
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Badshah MA, Koh NY, Zia AW, Abbas N, Zahra Z, Saleem MW. Recent Developments in Plasmonic Nanostructures for Metal Enhanced Fluorescence-Based Biosensing. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1749. [PMID: 32899375 PMCID: PMC7558009 DOI: 10.3390/nano10091749] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 01/14/2023]
Abstract
Metal-enhanced fluorescence (MEF) is a unique phenomenon of surface plasmons, where light interacts with the metallic nanostructures and produces electromagnetic fields to enhance the sensitivity of fluorescence-based detection. In particular, this enhancement in sensing capacity is of importance to many research areas, including medical diagnostics, forensic science, and biotechnology. The article covers the basic mechanism of MEF and recent developments in plasmonic nanostructures fabrication for efficient fluorescence signal enhancement that are critically reviewed. The implications of current fluorescence-based technologies for biosensors are summarized, which are in practice to detect different analytes relevant to food control, medical diagnostics, and forensic science. Furthermore, characteristics of existing fabrication methods have been compared on the basis of their resolution, design flexibility, and throughput. The future projections emphasize exploring the potential of non-conventional materials and hybrid fabrication techniques to further enhance the sensitivity of MEF-based biosensors.
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Affiliation(s)
- Mohsin Ali Badshah
- Department of Chemical and Biomolecular Engineering, University of California-Irvine, Irvine, CA 92697, USA
| | - Na Yoon Koh
- Plamica Labs, Batten Hall, 125 Western Ave, Allston, MA 02163, USA;
| | - Abdul Wasy Zia
- Institute of Structural Health Management, Faculty of Civil Engineering and Engineering Mechanics, Jiangsu University, Zhenjiang 212013, China;
| | - Naseem Abbas
- School of Mechanical Engineering, Chung-Ang University, Seoul 06974, Korea;
| | - Zahra Zahra
- Department of Civil & Environmental Engineering, University of California-Irvine, Irvine, CA 92697, USA;
| | - Muhammad Wajid Saleem
- Department of Mechanical Engineering, University of Engineering and Technology, Lahore 54890, Pakistan;
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14
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Tavakkoli Yaraki M, Daqiqeh Rezaei S, Tan YN. Simulation guided design of silver nanostructures for plasmon-enhanced fluorescence, singlet oxygen generation and SERS applications. Phys Chem Chem Phys 2020; 22:5673-5687. [PMID: 32103209 DOI: 10.1039/c9cp06029d] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Plasmonic nanostructures such as gold and silver could alter the intrinsic properties of fluorophores, photosensitizers or Raman reporters in their close vicinity. In this study, we have conducted systematic simulations to provide insight for the design of silver nanostructures with appropriate geometrical features for metal-enhanced fluorescence (MEF), metal-enhanced singlet oxygen generation (ME-SOG) and surface-enhanced Raman scattering (SERS) applications. The size-dependent optical properties and electric field enhancement of single and dimeric nanocubes were simulated. The extinction spectra of silver nanocubes were analysed by the multipole expansion method. Results show that a suitable size of Ag nanocubes for MEF and ME-SOG can be selected based on their maximum light scattering yield, the excitation and emission wavelengths of a particular fluorophore/photosensitizer and their maximum spectral overlap. Simulations of the 'hot-spot' or gap distance between two silver nanocubes with different configurations (i.e., face-to-face, edge-to-edge and corner-to-corner) were also performed. A direct correlation was found between the size and enhanced electric field around the Ag nanocubes simulated under 15 common Raman laser wavelengths from the UV to near-infrared region. The maximum SERS enhancement factor can be achieved by selecting the silver nanocubes with the right orientation, suitable edge length and gap distance that give the highest electric field at a specific Raman laser wavelength. It was also found that the higher order of silver nanostructures, e.g., trimer and tetramer, can lead to better enhancement effects. These simulation results can serve as generic guidelines to rationally design metal-enhancement systems including MEF, ME-SOG and SERS for different application needs without cumbersome optimization and tedious trial-and-error experimentation.
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Affiliation(s)
- Mohammad Tavakkoli Yaraki
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 138634, Singapore
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