Metal-enhanced fluorescence of dyes with quadrupole surface plasmon resonance of silver nanoparticles

Abstract

Silver colloidal films (SCFs) composed of homogeneous silver nanoparticles of 59-219 nm were synthesized for optimal fluorescence enhancement of chromophores with the dipole and quadrupole surface plasmons. Three chromophores whose...

Dual-Polarity Switching in Self-Powered Ag/MoS2/Ag Photodetectors

“…Silver nanoparticles of varying sizes and shapes in silver electrodes with length scales (diameter of nanospheres, curvature radius, or edge length of prisms) comparable with the wavelength of incident light can induce a nonhomogeneous polarization of surface plasmons and hence produce multipole (dipole and quadrupole) SPR modes with band broadening and redshifts in the resonance frequency . While smaller nanoparticles (less than 40 nm) show only dipole excitation, larger nanoparticles are expected to exhibit both dipole and multipole excitations along with red shift in resonance frequency, i.e., resonance at around 600 nm. , Also, from the larger nanoparticles (nanospheres having a diameter greater than 200 nm or nanoprisms with edge length larger than 100 nm), an LSPR response in the NIR range of spectral illumination can be expected. , …”

“…A part of the hot carriers are generated from the plasmon decay via indirect plasmon-induced charge transfer from metal to the conduction band of MoS 2 , and another part by thermionic emission, which will also favor charge transfer via tunneling across the metal–semiconductor interface. The driving potential for the charge carriers is affected due to the difference in the resonance frequency between the two metal contacts or the shift in resonance frequency of one contact compared to the other due to the difference in the average particle size of the nanoclusters, , which makes the device self-powered. Initially, the electrons flow from one contact (C 1 ) to MoS 2 , assuming C 1 takes the lead in the LSPR response and C 2 remains positive with respect to C 1 , i.e., current will flow from MoS 2 to C 1 inside the device (Figure d) and photocurrent is expected to flow from C 1 to C 2 .…”

Bioinspired Multifunctional Silver Nanoparticles for Optical Sensing Applications: A Sustainable Approach

“…The resonant excitation and the distance between nanoparticle−fluorophores decide applications. 159 The inclusion of cetyltrimethylammonium bromide on Ag glass surfaces leads to the formation of a triangular structure in the presence of a cationic surfactant. The size of the silver triangles was in the range of 100−450 nm which is increased more than traditional silver ,and hence, it is a suitable candidate for MEF.…”

Fluorescence enhancement of organic dyes by femtosecond laser-induced cavitation bubbles for crystal imaging

“…[16][17][18][19] Designed metallic nanoparticle arrays are used to induce fluorescence enhancement in organic dyes. [20][21][22] Some studies used metallic nanomaterials, including nanoparticles, 23,24 nanorods 25 and nanocubes 26 on the substrate in order to generate localized surface plasmons. The electromagnetic field enhancement near the metallic nanostructures is able to increase the excitation and emission rate of the fluorophores and results in the enhancement of fluorescence emission.…”