Surface Plasmon Resonance in Small Gold Nanoparticles: Introducing a Size-Dependent Plasma Frequency for Nanoparticles in Quantum Regime

Karimi, Somayeh; Moshaii, Ahmad; Abbasian, Sara; Nikkhah, Maryam

doi:10.1007/s11468-018-0866-4

Cited by 48 publications

(41 citation statements)

References 57 publications

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“…As mentioned above, two mechanisms are expected to contribute to the enhancement of photocatalytic activity of semiconductors by noble metal functionalization: namely, the extension of the light absorption region by surface plasmon effects and the suppression of charge recombination due to carrier separation at the metal-semiconductor Schottky contact. The surface plasmon resonance frequencies of gold nanoparticles and films embedded in various semiconductor matrices were found to be in the spectral range of 500–700 nm [ 54 , 55 , 56 , 57 , 58 , 59 ]. The resonance frequencies of platinum are also in the visible light spectrum [ 60 , 61 ].…”

Section: Resultsmentioning

confidence: 99%

Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

et al. 2021

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A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.

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Section: Resultsmentioning

confidence: 99%

Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

et al. 2021

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“…Based on the quantum size effect in NPs with sizes less than mean free path of electrons, a modified size-dependent dielectric function was considered. 53 Then, the absorption cross-section of spherical NPs was calculated by Mie theory. Finally, temperature increase of NPs by external illumination was calculated based on the results of Baffou, et al 46…”

Section: Calculation Methods For Photothermal Efficiencymentioning

confidence: 99%

“…is the size-dependent refractive index of nanoparticles with sizes less than mean free path of electron (for gold 42 nm), that ε ω; R ð Þ is modification of the Drude dielectric model for Au-NP with the quantum size effects. 53 Therefore, the size-dependent dielectric function for nanoparticles can be obtained from:…”

Section: Size-tunable Photothermal Conversion Efficiencies Of Gold Namentioning

confidence: 99%

<p>Development of Dual Functional Nucleic Acid Delivery Nanosystem for DNA Induced Silencing of Bcl-2 Oncogene</p>

Karimi¹,

Fouani²,

Moshaii³

et al. 2020

IJN

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Introduction: Cancer treatment using functionalized vehicles in order to block involved genes has attracted a remarkable interest. In this study, we investigated the cellular uptake and cytotoxic effects of three sizes of anti Bcl-2 DNAi-conjugated gold nanoparticles by MCF-7 cells. Methods: Three different sizes of gold nanoparticles were synthesized by citrate reduction method and after characterization, the nanoparticles were functionalized by Bcl-2 targeted DNAi. Cell internalization of the nanoparticles was analyzed by atomic absorption spectroscopy and light microscopy. The cytotoxic effects of the nanoparticles were investigated by MTT assay, flow cytometry and RT-PCR of the target gene. Results: While poor cell internalization of bare gold nanoparticles was observed, the results demonstrated that cellular uptake of DNAi-conjugated gold nanoparticles is completely sizedependent, and the largest nanoparticle (~42 nm) revealed the highest internalization rate compared to other sizes (~14 and~26 nm). Experimental findings showed that the DNAiconjugated gold nanoparticles induced apoptotic pathway by silencing of the targeted Bcl-2 gene. In addition, supplementary theoretical studies demonstrated that the 42 nm DNAiconjugated gold nanoparticles have great photothermal conversion efficiency for treatment under external illumination and these nanoparticles can be induced further cytotoxic effect by approximately 10°C temperature elevations. Conclusion: Remarkable photothermal properties of DNAi-conjugated 42 nm Au-NPs in parallel with their high cell internalization and cytotoxic effects introduce them as potential dual functional anticancer nanosystems.

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“…In the Rayleigh scattering regime, or taking the lowest order terms in a/l from the exact Mie solutions, the cross-sections of scattering (s sca ), extinction (s ext ), and absorption (s abs ) are given by s sca % 8p 3 k out 4 a 6 e np À e out e np þ 2e out 2 (11) s ext % s abs % 4pk out a 3 Im e np À e out e np þ 2e out (12) where k out is the wavevector outside of the nanoparticle. 4,10 The formulae for E out , s sca , s ext and s abs contain the factor e np À e out e np þ 2e out and hence all of the electric field, scattering, extinction and absorption will be maximized under the condition e np = À2e out (13) which is the Frölich condition.…”

Section: Lspr-old Materials In New Lightmentioning

confidence: 99%

“…2 For Au, the LSPR peak is shifted from 505 nm to 534 nm on going from a radius of 1.8 nm to 24 nm. 11 Larger nanospheres also exhibit higher order resonances but in a shorter wavelength range. Anisotropic nanoparticles exhibit LSPR at wavelengths much more red-shifted.…”

Section: Lspr-old Materials In New Lightmentioning

confidence: 99%

Plasmonic triangular nanoprism sensors

2021

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Surface Plasmon Resonance in Small Gold Nanoparticles: Introducing a Size-Dependent Plasma Frequency for Nanoparticles in Quantum Regime

Cited by 48 publications

References 57 publications

Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

Highly Porous and Ultra-Lightweight Aero-Ga2O3: Enhancement of Photocatalytic Activity by Noble Metals

<p>Development of Dual Functional Nucleic Acid Delivery Nanosystem for DNA Induced Silencing of Bcl-2 Oncogene</p>

Plasmonic triangular nanoprism sensors

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