Comparative analysis of response modes for gold nanoparticle biosensor based on localized surface plasmon resonance

Abstract

Abstract. The theoretical comparison of possible response measurement techniques for a biosensor based on localized surface plasmon resonance (LSPR) in spherical Au nanoparticle was made. The methods for measuring LSPR response considered differed in the treatment of the change of light extinction spectrum along the wavelength and extinction coordinate axes upon the formation of dense biomolecular monolayer on the surface of the sensitive element. In addition, the transformation of the extinction LSPR band with increase of the nanoparticle radius from 5 to 125 nm was investigated towards the optimization of LSPR response for dipolar and quadrupolar LSPR extinction peaks.A novel method for the measurement of wavelength shift was introduced and demonstrated to be more effective for estimation of the LSPR biosensor response as compared to commonly measured extinction peak shift. These techniques were proved to produce maximal LSPR response when large-size Au nanoparticle (with a radius of 125 nm) was used as a sensitive element of biosensor. The preferable mode of extinction difference measurement turned out to be , which is carried out at a wavelength of the extreme extinction spectrum derivative on a right slope of the LSPR peak. For this method, optimal nanoparticle radii were found to be about 40 nm for the dipolar LSPR peak and near 100-105 nm for the quadrupolar one.right V

Ordered gold nanoparticle arrays on glass and their characterization

“…This is expected in part from Mie theory, as Eq. (2) shows that the absorption cross-section increases with the (homogeneous) background refractive index. This is also apparent from computations of the heat loss distribution for 10 nm AuNPs bounded by cover media of different refractive indices, revealing increasing heat loss with increasing index, see Fig.…”

“…This is consistent with the literature [76] and expected theoretically (Eqs. (2), (3)). In air, for 10 nm AuNP arrays, the measured absorbance peak is 2.65 Â 10 À3 (Fig.…”

“…The unique chemical, optical and electro-kinetic properties of gold nanoparticles (AuNPs), which are size-and shape-dependent, have been widely used in catalysts, solar energy harvesting, and sensing applications [1][2][3][4][5]. Although e-beam lithography or focused ion beam milling are commonly used to fabricate metallic nano-structures, the serial nature of these processes and their high costs are limiting.…”

Chapter 13. Nanostructured Materials for Biosensor Applications: Comparative Review of Preparation Methods

“…43 In 1998, Murray used dodecanethiol as a stabilizer instead of citrate and NaBH 4 as oxidant for synthesis of colloidal NPs with diameters varied between of 1.5 and 5.2 nm. 44 It should be noted that the size and monodispersity of plasmonic NPs is of importance for LSPR biosensors, because, theoretically, bigger NP size and more narrow peak of absorbance reveal better sensitivity, 30,45,46 whereas the narrow peak of the absorbance spectrum is provided by the high monodispersity of NPs. In practice, different objects for biosensing require NPs with different size, so it is mandatory to develop techniques, which allow preparation of nanoparticles with high monodispersity and wide size range.…”