Enhancement of the resolution of surface plasmon resonance biosensors by control of the size and distribution of nanoparticles

Abstract

A new resolution-enhanced surface plasmon resonance (SPR) biosensor offers a tenfold improvement in resolution compared with conventional SPR biosensors in the detection of the surface coverage of biomaterials. The proposed optical biosensor, based on the attenuated total-reflection method, excites both the surface plasmons and particle plasmons to enhance the local electromagnetic field by control of the size and volume fraction of embedded Au nanoparticles to increase the resolution of the device. The SPR biosensor design is based on the Maxwell-Garnett model and the Fresnel equations, and the device is fabricated with a cosputtering deposition system.

Shift of localized surface plasmon resonance by Ar-ion irradiation of Ag–Au bimetallic films deposited on Al2O3 single crystals

“…Effects of the ion induced surface nanostructuring were studied using 100 keV Ar-ion irradiation of 30 nm Ag-Au bimetallic films deposited on Al 2 (with the irradiation fluence of 3.8 ×10 16 cm -2 ), and then reaches the stable value around 50% (Fig. 2b).…”

“…In the past decades, metallic nanoparticles either sustained on surfaces or dispersed in dielectric matrices have been extensively studied because of their pronounced optical and electrical properties [1][2][3][4][5][6][7][8]. Most of the studies have focused on localized surface plasmon excitation, which dominates the photoabsorption spectra in the visible range.…”

Ion irradiation synthesis of Ag–Au bimetallic nanospheroids in SiO2 glass substrate with tunable surface plasmon resonance frequency

“…[3][4][5][6][7][8][9][10][11][12] It has been demonstrated that particle size, shape, and component material play important roles in determining the sensitivity. [17][18][19] There has been a great deal of research conducted on controlling the morphology and composition of these nanoparticles. [17][18][19][20][21][22][23][24][25][26][27] The synergistic control of various parameters sensitive to the LSPR band includes both particle size and shape.…”

“…[17][18][19][20][21][22][23][24][25][26][27] The synergistic control of various parameters sensitive to the LSPR band includes both particle size and shape. [17][18][19][20][21][22][23] Further control of LSPR frequency over a wider range has been achieved by synthesizing bimetallic nanoparticles fabricated in the form of alloys of two metals. In general, the resulting LSPR frequency lies in between that of the pure components, and depends on the relative amounts of the two components.…”

“…Purely chemical synthetic routes such as innovative colloidal self-assembly, [18][19][20]24,26 lithography methods such as electron beam lithography 28 and nanosphere lithography, 27,29 thermal deposition, 25 laser irradiation, 30 ion implantation and consequent annealing, 31,32 and ion irradiation and subsequent annealing [33][34][35] have been developed for manufacturing high efficiency platforms for the LSPR-based sensors. Nowadays, colloidal chemistry can produce a myriad of metal NPs in solutions with a variety of morphologies from sphere to complex core-shell, with very good control of the size distribution; [17][18][19][20][21][22][23] this control over the size, composition, and morphology of the NPs in a system can produce dramatically different absorption features in the visible or near-infrared spectrum. However, the synthesis of these structures, in particular within a matrix, is a significant challenge.…”