1
|
In Situ Enhanced Raman and Photoluminescence of Bio-Hybrid Ag/Polymer Nanoparticles by Localized Surface Plasmon for Highly Sensitive DNA Sensors. Polymers (Basel) 2020; 12:polym12030631. [PMID: 32164297 PMCID: PMC7182923 DOI: 10.3390/polym12030631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 03/07/2020] [Accepted: 03/07/2020] [Indexed: 11/17/2022] Open
Abstract
We experimentally demonstrate the simultaneous enhancement of Raman and photoluminescence (PL) of core-shell hybrid nanoparticles consisting of Ag (core) and polydiacetylene (PDA, shell) through the assistance of localized surface plasmon (LSP) effect for the effective biosensor. Core-shell nanoparticles (NPs) are fabricated in deionized water through a sequential process of reprecipitation and self-assembly. The Raman signal of PDA on core-shell NPs is enhanced more than 100 times. Also, highly enhanced photoluminescence is observed on Ag/PDA hybrid NPs after coupling of the complementary t-DNA with p-DNA which are immobilized on PDA shell. This indicates that the core Ag affects the Raman and PL of PDA through the LSP resonance, which can be caused by the energy and/or charge transfer caused by the LSP coupling and the strong electromagnetic field near Ag NP surface. Only electrons present on the surface interact with the PDA shell, not involving the electrically neutral part of the electrons inside the Ag NP. Furthermore, this work shows that as prepared Ag/PDA NPs functionalized by probe DNA can sense the target DNA with an attomolar concentration (100 attomole).
Collapse
|
2
|
Jang D, Pramanik SK, Das A, Baek W, Heo JM, Ro HJ, Jun S, Park BJ, Kim JM. Photoinduced Reversible Bending and Guest Molecule Release of Azobenzene-Containing Polydiacetylene Nanotubes. Sci Rep 2019; 9:15982. [PMID: 31690756 PMCID: PMC6831582 DOI: 10.1038/s41598-019-52462-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 09/30/2019] [Indexed: 12/31/2022] Open
Abstract
Creation of hollow, one-dimensional nanomaterials has gained great recent attention in the chemical and material sciences. In a study aimed at discovering new functional materials of this type, we observed that an amphiphilic diacetylene (DA) derivative, containing an azobenzene moiety and an oligo-ethylene group, self-assembles to form nanotubes and undergoes photopolymerization to form hollow polydiacetylene (PDA) nanotubes with a uniform wall thickness and diameter. The azobenzene-PDA nanotubes are photoresponsive in that on-and-off UV-irradiation leads to a reversible morphological change between straight and bent forms in association with E-Z photoisomerization of the azobenzene group. Owing to the UV-induced structural change feature, the new DA and PDA nanotubes serve as a controlled release material. Accordingly, fluorescent rhodamine B encapsulated inside the nanotubes are effectively released by using repeated on-off UV irradiation. Furthermore, photo-release of rhodamine B was shown to occur in an artemia (brine shrimp).
Collapse
Affiliation(s)
- Daewoong Jang
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, Korea
| | - Sumit Kumar Pramanik
- CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364002, Gujarat, India
| | - Amitava Das
- CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, 364002, Gujarat, India.
| | - Woohyun Baek
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, Korea
| | - Jung-Moo Heo
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, Korea
| | - Hyun-Joo Ro
- Drug and Disease Target Team, Korea Basic Science Institute, Cheongu, 28119, Korea
| | - Sangmi Jun
- Drug and Disease Target Team, Korea Basic Science Institute, Cheongu, 28119, Korea
- Convergent Research Center for Emerging Virus Infection Korea Research Institute of Chemical Technology, Daejeon, 34114, Korea
| | - Bum Jun Park
- Department of Chemical Engineering, Kyung Hee University, Yongin, 17104, Korea.
| | - Jong-Man Kim
- Department of Chemical Engineering, Hanyang University, Seoul, 04763, Korea.
- Institute of Nano Science and Technology, Hanyang University, Seoul, 04763, Korea.
| |
Collapse
|
3
|
Krishnan D, Raj R B A, Gowd EB. Topochemical polymerization of hierarchically ordered diacetylene monomers within the block copolymer domains. Polym Chem 2019. [DOI: 10.1039/c9py00156e] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Effect of annealing conditions on the hierarchical ordering of PCDA monomers within the block copolymer supramolecules and their subsequent topochemical polymerization.
Collapse
Affiliation(s)
- Deepthi Krishnan
- Materials Science and Technology Division
- CSIR-National Institute for Interdisciplinary Science and Technology
- Trivandrum 695 019
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Amal Raj R B
- Materials Science and Technology Division
- CSIR-National Institute for Interdisciplinary Science and Technology
- Trivandrum 695 019
- India
| | - E. Bhoje Gowd
- Materials Science and Technology Division
- CSIR-National Institute for Interdisciplinary Science and Technology
- Trivandrum 695 019
- India
- Academy of Scientific and Innovative Research (AcSIR)
| |
Collapse
|
4
|
Tobias A, Rooke W, Hanks TW. Incorporation of gold nanoparticles into the bilayer of polydiacetylene unilamellar vesicles. Colloid Polym Sci 2019. [DOI: 10.1007/s00396-018-4441-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
5
|
Seo M, Park DH, Park BJ, Kim JM. Flexible patch-type hydrochromic polydiacetylene sensor for human sweat pore mapping. J Appl Polym Sci 2016. [DOI: 10.1002/app.44419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Minjeong Seo
- Department of Chemical Engineering; Hanyang University; Seoul 04763 Korea
| | - Dong-Hoon Park
- Department of Chemical Engineering; Hanyang University; Seoul 04763 Korea
| | - Bum Jun Park
- Department of Chemical Engineering; Kyung Hee University; Yongin-si Gyeonggi-do 17104 Korea
| | - Jong-Man Kim
- Department of Chemical Engineering; Hanyang University; Seoul 04763 Korea
- Institute of Nano Science and Technology, Hanyang University; Seoul 04763 Korea
| |
Collapse
|
6
|
Fluorometric Measurement of Individual Stomata Activity and Transpiration via a "Brush-on", Water-Responsive Polymer. Sci Rep 2016; 6:32394. [PMID: 27578430 PMCID: PMC5006157 DOI: 10.1038/srep32394] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/08/2016] [Indexed: 01/17/2023] Open
Abstract
Much of atmospheric water originates from transpiration, the process by which plants release H2O from pores, known as stomata, that simultaneously intake CO2 for photosynthesis. Controlling stomatal aperture can regulate the extent of water transport in response to dynamic environmental factors including osmotic stress, temperature, light, and wind. While larger leaf regions are often examined, the extent of water vapor release from individual stomata remains unexplored. Using a "brush-on" sensing material, we can now assess transpiration using a water-responsive, polydiacetylene-based coating on the leaves surfaces. By eliciting a fluorometric signal to passing water vapor, we obtained information regarding the activity of individual stomata. In this demonstration, our results prove that this coating can identify the proportion of active stomata and the extent of transpirational diffusion of water in response to different conditions.
Collapse
|
7
|
Parambath Kootery K, Jiang H, Kolusheva S, Vinod TP, Ritenberg M, Zeiri L, Volinsky R, Malferrari D, Galletti P, Tagliavini E, Jelinek R. Poly(methyl methacrylate)-supported polydiacetylene films: unique chromatic transitions and molecular sensing. ACS APPLIED MATERIALS & INTERFACES 2014; 6:8613-8620. [PMID: 24813239 DOI: 10.1021/am501414z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Polydiacetylenes (PDAs) constitute a family of conjugated polymers exhibiting unique colorimetric and fluorescence transitions, and have attracted significant interest as chemo- and biosensing materials. We spin-coated PDA films upon poly(methyl methacrylate) (PMMA), and investigated the photophysical properties and sensing applications of the new PDA configuration. Specifically, the as-polymerized blue PDA layer underwent distinct transformations to purple, red, and yellow phases, which could be quantified through conventional color scanning combined with application of image analysis algorithms. Furthermore, we recorded a reversible red-purple PDA transition that was induced by ultraviolet irradiation, a phenomenon that had not been reported previously in PDA film systems. We show that distinct color and fluorescence transitions were induced in the PMMA-supported PDA films by amphiphilic substances-surfactants and ionic liquids-and that the chromatic transformations were correlated to the analyte structures and properties. Overall, this study presents a new chromatic PDA film system in which noncovalent interactions between the PMMA substrate and spin-coated PDA give rise to distinct chromatic properties and molecular sensing capabilities.
Collapse
Affiliation(s)
- Kaviya Parambath Kootery
- Department of Chemistry and ‡Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev , Beer Sheva 84105, Israel
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Lee J, Pyo M, Lee SH, Kim J, Ra M, Kim WY, Park BJ, Lee CW, Kim JM. Hydrochromic conjugated polymers for human sweat pore mapping. Nat Commun 2014; 5:3736. [PMID: 24781362 PMCID: PMC4015324 DOI: 10.1038/ncomms4736] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 03/27/2014] [Indexed: 12/23/2022] Open
Abstract
Hydrochromic materials have been actively investigated in the context of humidity sensing and measuring water contents in organic solvents. Here we report a sensor system that undergoes a brilliant blue-to-red colour transition as well as ‘Turn-On’ fluorescence upon exposure to water. Introduction of a hygroscopic element into a supramolecularly assembled polydiacetylene results in a hydrochromic conjugated polymer that is rapidly responsive (<20 μs), spin-coatable and inkjet-compatible. Importantly, the hydrochromic sensor is found to be suitable for mapping human sweat pores. The exceedingly small quantities (sub-nanolitre) of water secreted from sweat pores are sufficient to promote an instantaneous colorimetric transition of the polymer. As a result, the sensor can be used to construct a precise map of active sweat pores on fingertips. The sensor technology, developed in this study, has the potential of serving as new method for fingerprint analysis and for the clinical diagnosis of malfunctioning sweat pores. Materials capable of colour changes in response to stimuli are useful in sensors and other applications. Here the authors show a conjugated polymer that rapidly responds to the presence of water, and use it as a sensor to map active sweat pores as a means of fingerprint analysis.
Collapse
Affiliation(s)
- Joosub Lee
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Minkyeong Pyo
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Sang-hwa Lee
- Department of Physics, Hanyang University, Seoul 133-791, Korea
| | - Jaeyong Kim
- 1] Department of Physics, Hanyang University, Seoul 133-791, Korea [2] Institute of Nano Science and Technology, Hanyang University, Seoul 133-791, Korea
| | - Moonsoo Ra
- Department of Electronic Engineering, Hanyang University, Seoul 133-791, Korea
| | - Whoi-Yul Kim
- Department of Electronic Engineering, Hanyang University, Seoul 133-791, Korea
| | - Bum Jun Park
- Department of Chemical Engineering, Kyung Hee University, Youngin-Si, Gyeonggi-do 446-701, Korea
| | - Chan Woo Lee
- Institute of Nano Science and Technology, Hanyang University, Seoul 133-791, Korea
| | - Jong-Man Kim
- 1] Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea [2] Institute of Nano Science and Technology, Hanyang University, Seoul 133-791, Korea
| |
Collapse
|
9
|
Shin H, Yoon B, Park IS, Kim JM. An electrothermochromic paper display based on colorimetrically reversible polydiacetylenes. NANOTECHNOLOGY 2014; 25:094011. [PMID: 24522234 DOI: 10.1088/0957-4484/25/9/094011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An electrothermochromic paper display composed of colorimetrically reversible polydiacetylenes (PDAs), utilizing screen printing on photopaper and patterning of electrically conductive wires on the reverse side, was developed. Heat generated by passing a current through the wires on the back of the photopaper induced a blue-to-red color transition of the PDA on the front at regions corresponding to the wires. This resulted in the generation of red-colored images, which disappeared when the supplied electric current was removed. The voltage at which the PDAs changed color could be controlled by using structured diacetylene (DA) monomers. A PDA-based seven-segment display has also been developed. By applying voltages, red-colored numeric digits from 0 to 9 can be displayed on the surface of the PDA layer.
Collapse
Affiliation(s)
- Hyora Shin
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | | | | | | |
Collapse
|
10
|
|
11
|
Yoon B, Shin H, Kang EM, Cho DW, Shin K, Chung H, Lee CW, Kim JM. Inkjet-compatible single-component polydiacetylene precursors for thermochromic paper sensors. ACS APPLIED MATERIALS & INTERFACES 2013; 5:4527-35. [PMID: 23469803 DOI: 10.1021/am303300g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Inkjet-printable diacetylene (DA) supramolecules, which can be dispersed in water without using additional surfactants, have been developed. The supramolecules are generated from DA monomers that contain bisurea groups, which are capable of forming hydrogen-bonding networks, and hydrophilic oligoethylene oxide moieties. Because of suitable size distribution and stability characteristics, the single DA component ink can be readily transferred to paper substrates by utilizing a common office inkjet printer. UV irradiation of the DA-printed paper results in generation of blue-colored polydiacetylene (PDA) images, which show reversible thermochromic transitions in specific temperature ranges. Inkjet-printed PDAs, in the format of a two-dimensional (2D) quick response (QR) code on a real parking ticket, serve as a dual anticounterfeiting system that combines easy decoding of the QR code and colorimetric PDA reversibility for validating the authenticity of the tickets. This single-component ink system has great potential for use in paper-based devices, temperature sensors, and anticounterfeiting barcodes.
Collapse
Affiliation(s)
- Bora Yoon
- Department of Chemical Engineering, Hanyang University, Seoul, Korea
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Lee J, Chang HT, An H, Ahn S, Shim J, Kim JM. A protective layer approach to solvatochromic sensors. Nat Commun 2013; 4:2461. [PMID: 24025981 PMCID: PMC3778510 DOI: 10.1038/ncomms3461] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 08/19/2013] [Indexed: 12/23/2022] Open
Abstract
As they have been designed to undergo colorimetric changes that are dependent on the polarity of solvents, the majority of conventional solvatochromic molecule based sensor systems inevitably display broad overlaps in their absorption and emission bands. As a result, colorimetric differentiation of solvents of similar polarity has been extremely difficult. Here we present a tailor-made colorimetric and fluorescence turn-on type solvatochromic sensor that enables facile identification of a specific solvent. The sensor system displays a colorimetric transition only when a thin protective layer, which protects the solvatochromic materials, is destroyed or disrupted by a specific solvent. The versatility of the strategy is demonstrated by designing a sensor that differentiates chloroform and dichloromethane colorimetrically and one that performs sequence selective colorimetric sensing. In addition, the approach is employed to construct a solvatochromic molecular AND logic gate. The new strategy could open new avenues for the development of novel solvatochromic sensors.
Collapse
Affiliation(s)
- Jung Lee
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Hyun Taek Chang
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Hyosung An
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Sora Ahn
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Jina Shim
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | - Jong-Man Kim
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
- Institute of Nano Science and Technology, Hanyang University, Seoul 133-791, Korea
| |
Collapse
|
13
|
Yoo I, Song S, Yoon B, Kim JM. Size-Controlled Fabrication of Polydiacetylene-Embedded Microfibers on a Microfluidic Chip. Macromol Rapid Commun 2012; 33:1256-61. [DOI: 10.1002/marc.201200073] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 03/23/2012] [Indexed: 01/22/2023]
|
14
|
|
15
|
Yoon B, Shin H, Yarimaga O, Ham DY, Kim J, Park IS, Kim JM. An inkjet-printable microemulsion system for colorimetric polydiacetylene supramolecules on paper substrates. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm30301a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
16
|
Yoon B, Ham DY, Yarimaga O, An H, Lee CW, Kim JM. Inkjet printing of conjugated polymer precursors on paper substrates for colorimetric sensing and flexible electrothermochromic display. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:5492-7. [PMID: 22052793 DOI: 10.1002/adma.201103471] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 09/26/2011] [Indexed: 05/22/2023]
Abstract
Inkjet-printable aqueous suspensions of conjugated polymer precursors are developed for fabrication of patterned color images on paper substrates. Printing of a diacetylene (DA)-surfactant composite ink on unmodified paper and photopaper, as well as on a banknote, enables generation of latent images that are transformed to blue-colored polydiacetylene (PDA) structures by UV irradiation. Both irreversible and reversible thermochromism with the PDA printed images are demonstrated and applied to flexible and disposable sensors and to displays.
Collapse
Affiliation(s)
- Bora Yoon
- Department of Chemical Engineering, Hanyang University, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
17
|
Dellepiane G, Cuniberti C, Alloisio M, Demartini A. Spectroscopical properties of organic/metal nanohybrids. Phys Chem Chem Phys 2010; 12:2968-74. [DOI: 10.1039/b912921a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Yoon J, Azizan KAB, Yoo HO, Okada S, Kim JM. Unusual photopolymerization behavior of amino Acid-derived polydiacetylene supramolecules. Macromol Rapid Commun 2009; 30:981-5. [PMID: 21706558 DOI: 10.1002/marc.200900016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 02/27/2009] [Accepted: 03/02/2009] [Indexed: 11/10/2022]
Abstract
UV-irradiation of aqueous suspensions of amino acid-derived amphiphilic diacetylene supramolecules promotes a process that involves initial formation of species that absorb at 640 nm followed by the generation of polymers that have longer wavelength (686 nm) absorbance. The initially formed intermediate polydiacetylenes display substantial colorimetric reversibility while the long wavelength absorbing polymers show irreversible thermochromism during heating and cooling cycles. The long wavelength absorbing polydiacetylenes, formed from amino acid-derived amphiphilic diacetylene supramolecules, are suggested to have more planer backbone structures that allow more efficient overlap of the conjugated p-orbitals.
Collapse
Affiliation(s)
- Jaewon Yoon
- Department of Chemical Engineering, Hanyang University, Seoul 133-791, Korea
| | | | | | | | | |
Collapse
|
19
|
Muniz-Miranda M, Giorgetti E, Margheri G, Sottini S, Giusti A, Dellepiane G. SERS study of self-assembled carbazolyl-diacetylene monolayers polymerized on gold surfaces. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2008.10.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
20
|
Giorgetti E, Cicchi S, Muniz-Miranda M, Margheri G, Del Rosso T, Giusti A, Rindi A, Ghini G, Sottini S, Marcelli A, Foggi P. Förster resonance energy transfer (FRET) with a donor–acceptor system adsorbed on silver or gold nanoisland films. Phys Chem Chem Phys 2009; 11:9798-803. [DOI: 10.1039/b909123h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
Deb P, Yuan Z, Ramsey L, Hanks TW. Synthesis and Optical Properties of Chiral Polydiacetylenes. Macromolecules 2007. [DOI: 10.1021/ma070038x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Prasant Deb
- Department of Chemistry, Furman University, Greenville, South Carolina 29613
| | - Zhongzhe Yuan
- Department of Chemistry, Furman University, Greenville, South Carolina 29613
| | - Lee Ramsey
- Department of Chemistry, Furman University, Greenville, South Carolina 29613
| | - Timothy W. Hanks
- Department of Chemistry, Furman University, Greenville, South Carolina 29613
| |
Collapse
|