SERS characterization of Rhodamine 6G dye molecule response using thin gold film covalently immobilized with gold nanourchins

Mohammad E. Khosroshahi, Yesha Patel, Christine Gaoiran, Vithurshan Umashanker

Article ID: 10951
Vol 8, Issue 2, 2025

VIEWS - 214 (Abstract)

Abstract


We report on the measurement of the response of Rhodamine 6G (R6G) dye to enhanced local surface plasmon resonance (LSPR) using a plasmonic-active nanostructured thin gold film (PANTF) sensor. This sensor features an active area of approximately ≈ 2.5 × 1013 nm2 and is immobilized with gold nanourchins (GNU) on a thin gold film substrate (TGFS). The hexane-functionalized TGFS was immobilized with a 90 nm diameter GNU via the strong sulfhydryl group (SH) thiol bond and excited by a 637 nm Raman probe. To collect both Raman and SERS spectra, 10 μL of R6G was used at concentrations of 1 μM (6 × 1012 molecules) and 10 mM (600 × 1014 molecules), respectively. FT-NIR showed a higher reflectivity of PANTF than TGFS. SERS was performed three times at three different laser powers for TGFS and PANTF with R6G. Two PANTF substrates were prepared at different GNU incubation times of 10 and 60 min for the purpose of comparison. The code for processing the data was written in Python. The data was filtered using the filtfilt filter from scipy.signals, and baseline corrected using the Improved Asymmetric Least Squares (ISALS) function from the pybaselines.Whittaker library. The results were then normalized using the minmax_scale function from sklearn.preprocessing. Atomic force microscopy (AFM) was used to capture the topography of the substrates. Signals exhibited a stochastic fluctuation in intensity and shape. An average corresponding enhancement factor (EF) of 0.3 × 105 and 0.14 × 105 was determinedforPANTFincubated at 10 and 60 min, respectively.


Keywords


thin film; gold nanourchins; R6G molecule; SERS; FT-NIR; enhancement factor

Full Text:

PDF


References


Betzig E, Chichester RJ. Single Molecules Observed by Near-Field Scanning Optical Microscopy. Science. 1993; 262(5138): 1422-1425. doi: 10.1126/science.262.5138.1422 Macklin JJ, Trautman JK, Harris TD, et al. Imaging and Time-Resolved Spectroscopy of Single Molecules at an Interface. Science. 1996; 272(5259): 255-258. doi: 10.1126/science.272.5259.255 Qiu Y, Kuang C, Liu X, et al. Single-Molecule Surface-Enhanced Raman Spectroscopy. Sensors. 2022; 22(13): 4889. doi: 10.3390/s22134889 He S, Chua J, Tan EKM, et al. Optimizing the SERS enhancement of a facile gold nanostar immobilized paper-based SERS substrate. RSC Advances. 2017; 7(27): 16264-16272. doi: 10.1039/c6ra28450g Szekeres GP, Kneipp J. SERS Probing of Proteins in Gold Nanoparticle Agglomerates. Frontiers in Chemistry. 2019; 7. doi: 10.3389/fchem.2019.00030 Hanna K, Krzoska E, Shaaban A, et al. Raman spectroscopy: Current applications in breast cancer diagnosis, challenges and future prospects. British Journal of Cancer. 2022; 126: 1125-1139. doi: 10.1038/s41416-021-01659-5 Khosroshahi ME, Chabok R, Chung N, et al. Optimization of immersion direction and time of covalently self-assembled monolayer gold nanourchins on glass as SERS substrate. Journal of Nanoparticle Research. 2023; 25(5). doi: 10.1007/s11051-023-05741-2 Shera EB, Seitzinger NK, Davis LM, et al. Detection of single fluorescent Molecules. Chemistry Physics Letter. 1990; 174(6): 553-557. doi: 10.1016/0009-2614(90)85485-U Eigen M, Rigler R. Sorting single molecules: application to diagnostics and evolutionary biotechnology. Proceedings of the National Academy of Sciences. 1994; 91(13): 5740-5747. doi: 10.1073/pnas.91.13.5740 Krug JT, Wang GD, Emory SR, et al. Efficient Raman Enhancement and Intermittent Light Emission Observed in Single Gold Nanocrystals. Journal of the American Chemical Society. 1999; 121(39): 9208-9214. doi: 10.1021/ja992058n Kneipp K, Kneipp H, Manoharan R, et al. Extremely Large Enhancement Factors in Surface-Enhanced Raman Scattering for Molecules on Colloidal Gold Clusters. Applied Spectroscopy. 1998; 52(12): 1493-1497. doi: 10.1366/0003702981943059 Ambrose WP, Goodwin PM, Martin JC, et al. Alterations of single molecule fluorescence lifetimes in near-field optical microscopy. Science. 1994; 265(5170): 364-367. doi: 10.1126/science.265.5170.364 Ha T, Enderle T, Ogletree DF, et al. Probing the interaction between two single molecules: fluorescence resonance energy transfer between a single donor and a single acceptor. Proceedings of the National Academy of Sciences. 1996; 93(13): 6264-6268. doi: 10.1073/pnas.93.13.6264 Blackie EJ, Le Ru EC, Etchegoin PG. Single-Molecule Surface-Enhanced Raman Spectroscopy of Nonresonant Molecules. Journal of the American Chemical Society. 2009; 131(40): 14466-14472. doi: 10.1021/ja905319w Lin J, Huang Z, Lin X, et al. Rapid and label-free urine test based on surface-enhanced Raman spectroscopy for the non-invasive detection of colorectal cancer at different stages. Biomedical Optics Express. 2020; 11(12): 7109. doi: 10.1364/boe.406097 Khosroshahi ME, Patel Y, Umashanker V, et al. Fabrication of and characterization of directional antibody-conjugated gold nanourchin colloid and effect of laser polarization on SERS detection of breast cancer biomarker in serum. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2024; 694: 134035. doi: 10.1016/j.colsurfa.2024.134035 Willets KA, Van Duyne RP. Localized Surface Plasmon Resonance Spectroscopy and Sensing. Annual Review of Physical Chemistry. 2007; 58(1): 267-297. doi: 10.1146/annurev.physchem.58.032806.104607 Petryayeva E, Krull UJ. Localized surface plasmon resonance: Nanostructures, bioassays and biosensing—A review. Analytica Chimica Acta. 2011; 706(1): 8-24. doi: 10.1016/j.aca.2011.08.020 Jain PK, Lee KS, El-Sayed IH, et al. Calculated Absorption and Scattering Properties of Gold Nanoparticles of Different Size, Shape, and Composition: Applications in Biological Imaging and Biomedicine. The Journal of Physical Chemistry B. 2006; 110(14): 7238-7248. doi: 10.1021/jp057170o Noguez C. Surface Plasmons on Metal Nanoparticles: The Influence of Shape and Physical Environment. The Journal of Physical Chemistry C. 2007; 111(10): 3806-3819. doi: 10.1021/jp066539m Hassannejad Z, Khosroshahi ME. Synthesis and evaluation of time dependent optical properties of plasmonic–magnetic nanoparticles. Optical Materials. 2013; 35(3): 644-651. doi: 10.1016/j.optmat.2012.10.019 Khlebtsov B, Zharov V, Melnikov A, et al. Optical amplification of photothermal therapy with gold nanoparticles and nanoclusters. Nanotechnology. 2006; 17(20): 5167-5179. doi: 10.1088/0957-4484/17/20/022 Huang X, Jain PK, El-Sayed IH, et al. Gold Nanoparticles: Interesting Optical Properties and Recent Applications in Cancer Diagnostics and Therapy. Nanomedicine. 2007; 2(5): 681-693. doi: 10.2217/17435889.2.5.681 Otto A, Mrozek I, Grabhorn H, et al. Surface-enhanced Raman scattering. Journal of Physics: Condensed Matter. 1992; 4(5): 1143-1152. doi: 10.1088/0953-8984/4/5/001 Rodríguez-Oliveros R, Sánchez-Gil JA. Gold nanostars as thermoplasmonic nanoparticles for optical heating. Optics Express. 2011; 20(1): 621. doi: 10.1364/oe.20.000621 Hao F, Nehl CL, Hafner JH, et al. Plasmon Resonances of a Gold Nanostar. Nano Letters. 2007; 7(3): 729-732. doi: 10.1021/nl062969c Pallavicini P, Donà A, Casu A, et al. Triton X-100 for three-plasmon gold nanostars with two photothermally active NIR (near IR) and SWIR (short-wavelength IR) channels. Chemical Communications. 2013; 49(56): 6265. doi: 10.1039/c3cc42999g Khosroshahi ME, Patel Y. Reflective FT‐NIR and SERS studies of HER‐II breast cancer biomarker using plasmonic‐active nanostructured thin film immobilized oriented antibody. Journal of Biophotonics. 2022; 16(3). doi: 10.1002/jbio.202200252 Taylor AD, Lu C, Geyer S, et al. Thin film based plasmon nanorulers. Applied Physics Letters. 2016; 109(1). doi: 10.1063/1.4955036 Hutter T, Huang FM, Elliott SR, et al. Near-Field Plasmonics of an Individual Dielectric Nanoparticle above a Metallic Substrate. The Journal of Physical Chemistry C. 2013; 117(15): 7784-7790. doi: 10.1021/jp400963f Baumberg JJ, Aizpurua J, Mikkelsen MH, et al. Extreme nanophotonics from ultrathin metallic gaps. Nature Materials. 2019; 18: 668-678. doi: 10.1038/s41563-019-0290-y de Barros A, Shimizu FM, de Oliveira CS, et al. Dynamic Behavior of Surface-Enhanced Raman Spectra for Rhodamine 6G Interacting with Gold Nanorods: Implication for Analyses under Wet versus Dry Conditions. ACS Applied Nano Materials. 2020; 3(8): 8138-8147. doi: 10.1021/acsanm.0c01530 Burtsev V, Miliutina E, Ulbrich P, et al. Immobilization of Gold Nanoparticles in Localized Surface Plasmon Polariton-Coupled Hot Spots via Photolytic Dimerization of Aromatic Amine Groups for SERS Detection in a Microfluidic Regime. ACS Applied Nano Materials. 2022; 5(2): 1836-1844. doi: 10.1021/acsanm.1c03413 Ma H, Zhang S, Yuan G, et al. Surface-enhanced Raman spectroscopy (SERS) activity of gold nanoparticles Prepared using an automated loop flow reactor. Applied Spectroscopy. 2023; 77(10): 1163-1172. doi: 10.1177/00037028231196907 Kau J, Chen X, Chin C, et al. Silver Nanocube-Decorated PVDF Membranes for SERS Substrates. ACS Applied Nano Materials. 2023; 6(11): 9148-9158. doi: 10.1021/acsanm.3c00202 Fu J, Zhang H, Xiang Z, et al. Biologically Inspired Superwetting Surface Enhanced Raman Scattering (SERS) Substrates. ACS Applied Nano Materials. 2024; 7(20): 23337-23367. doi: 10.1021/acsanm.4c04342 Tang J, Hao J, Li Z, et al. Towards understanding hybrid influencing mechanisms of substrate microstructure on SERS effect. Applied Surface Science. 2024; 660: 159974. doi: 10.1016/j.apsusc.2024.159974 Suzuki M, Niidome Y, Kuwahara Y, et al. Surface-Enhanced Nonresonance Raman Scattering from Size- and Morphology-Controlled Gold Nanoparticle Films. The Journal of Physical Chemistry B. 2004; 108(31): 11660-11665. doi: 10.1021/jp0490150 Atta S, Canning AJ, Vo-Dinh T. A simple low-cost flexible plasmonic patch based on spiky gold nanostars for ultra-sensitive SERS sensing. The Analyst. 2024; 149(7): 2084-2096. doi: 10.1039/d3an02246c Pal A, Varma MM. Study of Surface-enhanced Raman scattering of Rhodamine 6G from repeated dewetted gold thin film. In: Proceedings of 2024 IEEE Applied Sensing Conference (APSCON); 22–24 January 2024; Goa, India. Ujihara M, Dang N, Imae T. Surface-Enhanced Resonance Raman Scattering of Rhodamine 6G in Dispersions and on Films of Confeito-Like Au Nanoparticles. Sensors. 2017; 17(11): 2563. doi: 10.3390/s17112563 Cheong Y, Kim YJ, Kang H, et al. Rapid label-free identification of Klebsiella pneumoniae antibiotic resistant strains by the drop-coating deposition surface-enhanced Raman scattering method. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2017; 183: 53-59. doi: 10.1016/j.saa.2017.04.044 Payne EK, Rosi NL, Xue C, et al. Sacrificial Biological Templates for the Formation of Nanostructured Metallic Microshells. Angewandte Chemie International Edition. 2005; 44(32): 5064-5067. doi: 10.1002/anie.200500988 Hrelescu C, Sau TK, Rogach AL, et al. Selective Excitation of Individual Plasmonic Hotspots at the Tips of Single Gold Nanostars. Nano Letters. 2011; 11(2): 402-407. doi: 10.1021/nl103007m Indrasekara ASDS, Meyers S, Shubeita S, et al. Gold nanostar substrates for SERS-based chemical sensing in the femtomolar regime. Nanoscale. 2014; 6(15): 8891-8899. doi: 10.1039/c4nr02513j Su KH, Wei QH, Zhang X, et al. Interparticle Coupling Effects on Plasmon Resonances of Nanogold Particles. Nano Letters. 2003; 3(8): 1087-1090. doi: 10.1021/nl034197f Li R, Li H, Pan S, et al. Surface-enhanced Raman scattering from rhodamine 6G on gold-coated self-organized silicon nanopyramidal array. Journal of Materials Research. 2013; 28(24): 3401-3407. doi: 10.1557/jmr.2013.352 Sil S, Kuhar N, Acharya S, et al. Is Chemically Synthesized Graphene ‘Really’ a Unique Substrate for SERS and Fluorescence Quenching? Scientific Reports. 2013; 3(1). doi: 10.1038/srep03336 Wahadoszamen Md, Rahaman A, Hoque NMdR, et al. Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy. Journal of Spectroscopy. 2015; 2015: 1-8. doi: 10.1155/2015/895317 Zhang Y, Zheng, guo, et al. Biosynthesis of gold nanoparticles using chloroplasts. International Journal of Nanomedicine. 2011: 2899. doi: 10.2147/ijn.s24785 Huang D, Cui J, Chen X. A morpholinium surfactant crystallization induced formation of Au nanoparticle sheet-like assemblies with uniform SERS activity. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2014; 456: 100-107. doi: 10.1016/j.colsurfa.2014.05.027 Zhong F, Wu Z, Guo J, et al. Porous Silicon Photonic Crystals Coated with Ag Nanoparticles as Efficient Substrates for Detecting Trace Explosives Using SERS. Nanomaterials. 2018; 8(11): 872. doi: 10.3390/nano8110872 Wu CY, Huang CC, Jhang JS, et al. Hybrid surface-enhanced Raman scattering substrate from gold nanoparticle and photonic crystal: Maneuverability and uniformity of Raman spectra. Optics Express. 2009; 17(24): 21522. doi: 10.1364/oe.17.021522 Basche T, Moerner WE, Orrite M, et al. Single-molecule optical detection, imaging and spectroscopy. Wiley-VCH; 1996. Donhauser ZJ, Mantooth BA, Kelly KF, et al. Conductance Switching in Single Molecules Through Conformational Changes. Science. 2001; 292(5525): 2303-2307. doi: 10.1126/science.1060294 Xu H, Bjerneld EJ, Käll M, et al. Spectroscopy of Single Hemoglobin Molecules by Surface Enhanced Raman Scattering. Physical Review Letters. 1999; 83(21): 4357-4360. doi: 10.1103/physrevlett.83.4357 Weiss A, Haran G. Time-Dependent Single-Molecule Raman Scattering as a Probe of Surface Dynamics. The Journal of Physical Chemistry B. 2001; 105(49): 12348-12354. doi: 10.1021/jp0126863 Galloway CM, Le Ru EC, Etchegoin PG. Single-molecule vibrational pumping in SERS. Physical Chemistry Chemical Physics. 2009; 11(34): 7372. doi: 10.1039/b904638k Emory SR, Jensen RA, Wenda T, et al. Re-examining the origins of spectral blinking in single-molecule and single-nanoparticleSERS. Faraday Discuss. 2006; 132: 249-259. doi: 10.1039/b509223j Miranda AM, Castilho-Almeida EW, Martins Ferreira EH, et al. Line shape analysis of the Raman spectra from pure and mixed biofuels esters compounds. Fuel. 2014; 115: 118-125. doi: 10.1016/j.fuel.2013.06.038 He XN, Gao Y, Mahjouri-Samani M, et al. Surface-enhanced Raman spectroscopy using gold-coated horizontally aligned carbon nanotubes. Nanotechnology. 2012; 23(20): 205702. doi: 10.1088/0957-4484/23/20/205702 Jiang, Bosnick K, Maillard M, et al. Single Molecule Raman Spectroscopy at the Junctions of Large Ag Nanocrystals. The Journal of Physical Chemistry B. 2003; 107(37): 9964-9972. doi: 10.1021/jp034632u Bizzarri AR, Cannistraro S. Lévy Statistics of Vibrational Mode Fluctuations of Single Molecules from Surface-Enhanced Raman Scattering. Physical Review Letters. 2005; 94(6). doi: 10.1103/physrevlett.94.068303 Ruan C, Wang W, Gu B. Single‐molecule detection of thionine on aggregated gold nanoparticles by surface enhanced Raman scattering. Journal of Raman Spectroscopy. 2007; 38(5): 568-573. doi: 10.1002/jrs.1691 Sotelo J, Ederth J, Niklasson G. Optical properties of polycrystalline metallic films. Physical Review B. 2003; 67(19). doi: 10.1103/physrevb.67.195106 Qian H, Xiao Y, Lepage D, et al. Quantum Electrostatic Model for Optical Properties of Nanoscale Gold Films. Nanophotonics. 2015; 4(4): 413-418. doi: 10.1515/nanoph-2015-0022 Zhang Z, Yang P, Xu H, et al. Surface enhanced fluorescence and Raman scattering by gold nanoparticle dimers and trimers. Journal of Applied Physics. 2013; 113(3). doi: 10.1063/1.4776227 Fan X, Zheng W, Singh DJ. Light scattering and surface plasmons on small spherical particles. Light: Science & Applications. 2014; 3(6): e179-e179. doi: 10.1038/lsa.2014.60 Nie S, Emory SR. Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering. Science. 1997; 275(5303): 1102-1106. doi: 10.1126/science.275.5303.1102 Canovi M, Lucchetti J, Stravalaci M, et al. Applications of Surface Plasmon Resonance (SPR) for the Characterization of Nanoparticles Developed for Biomedical Purposes. Sensors. 2012; 12(12): 16420-16432. doi: 10.3390/s121216420 Pyrak E, Jaworska A, Kudelski A. SERS Studies of Adsorption on Gold Surfaces of Mononucleotides with Attached Hexanethiol Moiety: Comparison with Selected Single-Stranded Thiolated DNA Fragments. Molecules. 2019; 24(21): 3921. doi: 10.3390/molecules24213921 Lévêque G, Martin OJF. Optical interactions in a plasmonic particle coupled to a metallic film. Optics Express. 2006; 14(21): 9971. doi: 10.1364/oe.14.009971 Mock JJ, Hill RT, Degiron A, et al. Distance-Dependent Plasmon Resonant Coupling between a Gold Nanoparticle and Gold Film. Nano Letters. 2008; 8(8): 2245-2252. doi: 10.1021/nl080872f Le Ru EC, Etchegoin PG, Meyer M. Enhancement factor distribution around a single surface-enhanced Raman scattering hot spot and its relation to single molecule detection. The Journal of Chemical Physics. 2006; 125(20). doi: 10.1063/1.2390694 Zhang K, Zeng T, Tan X, et al. A facile surface-enhanced Raman scattering (SERS) detection of rhodamine 6G and crystal violet using Au nanoparticle substrates. Applied Surface Science. 2015; 347: 569-573. doi: 10.1016/j.apsusc.2015.04.152 Sun S, Wu P. Competitive surface-enhanced Raman scattering effects in noble metal nanoparticle-decorated graphene sheets. Physical Chemistry Chemical Physics. 2011; 13(47): 21116. doi: 10.1039/c1cp22727k Zhang XF, Liu SP, Shao XN. Noncovalent binding of xanthene and phthalocyanine dyes with graphene sheets: The effect of the molecular structure revealed by a photophysical study. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2013; 113: 92-99. doi: 10.1016/j.saa.2013.04.066 Dieringer JA, Lettan RB, Scheidt KA, et al. A Frequency Domain Existence Proof of Single-Molecule Surface-Enhanced Raman Spectroscopy. Journal of the American Chemical Society. 2007; 129(51): 16249-16256. doi: 10.1021/ja077243c Zrimsek AB, Chiang N, Mattei M, et al. Single-Molecule Chemistry with Surface- and Tip-Enhanced Raman Spectroscopy. Chemical Reviews. 2016; 117(11): 7583-7613. doi: 10.1021/acs.chemrev.6b00552 Marshall ARL, Stokes J, Viscomi FN, et al. Determining molecular orientation via single molecule SERS in a plasmonic nano-gap. Nanoscale. 2017; 9(44): 17415-17421. doi: 10.1039/c7nr05107g Rai VN, Srivastava AK. Correlation between optical and morphological properties of nanostructured gold thin film. JSM Nanotechnology & Nanomedicine. 2016; 4(1). Qin L, Zou S, Xue C, et al. Designing, fabricating, and imaging Raman hot spots. Proceedings of the National Academy of Sciences. 2006; 103(36): 13300-13303. doi: 10.1073/pnas.0605889103 Ortega MA, Rodriguez L, Castillo J, et al. Thermo-optical properties of gold nanoparticles in colloidal systems. Journal of Optics A: Pure and Applied Optics. 2008; 10(10): 104024. doi: 10.1088/1464-4258/10/10/104024 Seol Y, Carpenter AE, Perkins TT. Gold nanoparticles: enhanced optical trapping and sensitivity coupled with significant heating. Optics Letters. 2006; 31(16): 2429. doi: 10.1364/ol.31.002429 Phuoc T, Massoudi M, Wang P. Laser-Induced Motion of a Nanofluid in a Micro-Channel. Fluids. 2016; 1(4): 35. doi: 10.3390/fluids1040035 Zhao BS, Koo YM, Chung DS. Separations based on the mechanical forces of light. Analytica Chimica Acta. 2006; 556(1): 97-103. doi: 10.1016/j.aca.2005.06.065 Shakib S, Rogez B, Khadir S, et al. Microscale Thermophoresis in Liquids Induced by Plasmonic Heating and Characterized by Phase and Fluorescence Microscopies. The Journal of Physical Chemistry C. 2021; 125(39): 21533-21542. doi: 10.1021/acs.jpcc.1c06299 Hrelescu C, Sau TK, Rogach AL, et al. Single gold nanostars enhance Raman scattering. Applied Physics Letters. 2009; 94(15). doi: 10.1063/1.3119642 Giannini V, Sánchez-Gil JA. Calculations of light scattering from isolated and interacting metallic nanowires of arbitrary cross section by means of Green’s theorem surface integral equations in parametric form. Journal of the Optical Society of America A. 2007; 24(9): 2822. doi: 10.1364/josaa.24.002822 Xu H. Theoretical study of coated spherical metallic nanoparticles for single-molecule surface-enhanced spectroscopy. Applied Physics Letters. 2004; 85(24): 5980-5982. doi: 10.1063/1.1833570 Yu M, Huang Z, Liu Z, et al. Annealed gold nanoshells with highly-dense hotspots for large-area efficient Raman scattering substrates. Sensors and Actuators B: Chemical. 2018; 262: 845-851. doi: 10.1016/j.snb.2018.02.048 Lai CH, Wang GA, Ling TK, et al. Near infrared surface-enhanced Raman scattering based on star-shaped gold/silver nanoparticles and hyperbolic metamaterial. Scientific Reports. 2017; 7(1). doi: 10.1038/s41598-017-05939-0 Heinzmann U, Holloway S, Kleyn AW, et al. Orientation in molecule—surface interactions. Journal of Physics: Condensed Matter. 1996; 8(19): 3245-3269. doi: 10.1088/0953-8984/8/19/002 Canfield BK, Kujala S, Kauranen M, et al. Remarkable polarization sensitivity of gold nanoparticle arrays. Applied Physics Letters. 2005; 86(18). doi: 10.1063/1.1924886 Kim GW, Ha JW. Polarization-Sensitive Single Dipoles Generated from Multiple Sharp Branches on the Surfaces of Single Gold Nanourchins. The Journal of Physical Chemistry C. 2017; 121(36): 19975-19982. doi: 10.1021/acs.jpcc.7b06823



DOI: https://doi.org/10.24294/can10951

Refbacks

  • There are currently no refbacks.


Copyright (c) 2025 Author(s)

License URL: https://creativecommons.org/licenses/by/4.0/

This site is licensed under a Creative Commons Attribution 4.0 International License.