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ALT'23 The 30th International Conference on Advanced Laser Technologies
B-I-24
Enhancement of near field and local absorption in plasmonic nanoparticle-protein fluorescent complexes
A. Yakunin1, S. Zarkov1, Yu. Avetisyan1, G. Akchurin1'2, I. Meerovich3, A. Savitsky3, V. Tuchin1'2'4
1-Institute of Precision Mechanics and Control, FRC "Saratov Research Centre ofRussian Academy of Sciences, "
Rabochaya str. 24, Saratov, 410028, Russia 2- Saratov State University, Astrakhanskaya str. 83, Saratov, 410012, Russia 3- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences,
LeninskyAve. 33, bld. 2, Moscow, 119071, Russia 4- Tomsk State University, Lenin's av. 36, Tomsk, 634050, Russia
e-mail: yakunin@iptmuran.ru
The phenomenon of localized surface plasmon resonance (LSPR) is caused by collective oscillations of conduction band electrons in the metal nanostructures under the influence of irradiating light. At present, this effect, which leads to a significant enhancement of the field in the vicinity of irradiated nanoparticles at resonant wavelengths, attracts increased attention of researchers and has found a wide variety of applications
[1], ranging from technologies of local hyperthermia and plasmon photocatalysis to SERS and plasmon-enhanced fluorescence (PEF). Developing the study of the PEF of plasmon-protein fluorescent complexes
[2], we present the results of calculations of the near-field enhancement in the vicinity of nanospheres synthesized from various materials - silver, gold, and copper. The solution of the problem of the distribution of the electric field during the irradiation of the nanosphere with an electromagnetic wave was carried out using both an analytical model (electrostatic approximation) and a finite element method implemented in the COMSOL software environment. The calculation models were verified in [3,4].
Since the fluorescence radiation power is proportional to the flux of exciting photons [5], it is of practical interest for the synthesis of efficient plasmon-protein fluorescent complexes to know the integral of the field amplification factor Is in the vicinity of nanospheres. A comparative analysis of the obtained spectral dependences of Is has shown that these dependences for nanospheres synthesized from various materials under study differ qualitatively and quantitatively from each other. However, their common feature is a certain correlation of Is with the corresponding absorption cross section spectra of Cabs nanoparticles. As a result of the studies, it was found that for a certain combination of factors (optical properties of the metal, size of the nanosphere, wavelength of the incident radiation), such a correlation between the amplification of the excitation field of the fluorophore and the resonant absorption of radiation by the nanoparticle can play a negative role. This is due to the fact that the heating induced by light absorption in the vicinity of a nanoparticle can lead to an undesirable effect of fluorescence quenching, which was experimentally shown in [6]. In our work, we propose a composite criterion for assessing the quality of plasmon-protein fluorescent complexes, taking into account the influence of the induced temperature field, and present the results of evaluating the effectiveness of complexes focused on the use of fluorophores in the range from UV to near IR. The prospects for the use of complexes based on silver nanospheres are shown, and the conditions for the competitiveness of complexes based on cheap copper nanospheres in comparison with traditional complexes based on gold nanospheres are determined.
The research was carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation (theme No. 121022000123-8).
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[2] S.V. Zar'kov et al., Interaction of laser radiation and complexes of gold nanoparticles linked with proteins, Quantum Electronics, vol. 51(1), pp. 52-63 (2021).
[3] A.N. Yakunin et al., Modeling of Laser-Induced Plasmon Effects in GNS-DLC-Based Material for Application in X-ray Source Array Sensors. Sensors, vol. 21, art. 1248, (2021), https://doi.org/10.3390/s21041248.
[4] A.N. Yakunin et al., Photoemission of Plasmonic Gold Nanostars in Laser-Controlled Electron Current Devices for Technical and Biomedical Applications. Sensors, vol. 22, art. 4127, (2022), https://doi.org/10.3390/s22114127.
[5] W. Deng et al., Metal-enhanced fluorescence in the life sciences: Here, now and beyond. Physical Chemistry Chemical Physics, vol. 15, pp. 1569515708, (2013), https://doi.org/10.1039/C3CP50206F.
[6] J.V. Pellegrotti et al., Plasmonic Photothermal Fluorescence Modulation for Homogeneous Biosensing. ACS Sens., vol. 1, is. 11, pp. 1351-1357, (2016), https://doi.org/10.1021/acssensors.6b00512.
