Supported silver clusters as nanoplasmonic transducers for protein sensing

Abstract

a b s t r a c tTransducers for optical sensing of proteins are prepared using cluster beam deposition on quartz substrates. Surface plasmon resonance phenomenon of the supported silver clusters is used for the detection. It is shown that surface immobilisation procedure providing adhesion of the silver clusters to quartz and functionalisation of cluster surfaces for antibody coupling are the key issues for cluster stability and protein detection. Focus was put on these tasks and the processes have been optimised. In particular, conditions for coupling of the antibodies to the clusters are developed providing an enhancement of the plasmon absorption band used for the detection. Atomic force microscopy study allows to suggest that immobilisation of antibodies on silver clusters has been achieved, thus giving a possibility to incubate and detect an antigen of interest. Hence, by applying the developed preparation stages and protein immobilisation scheme the sensing of protein of interest can be assured using a relatively simple optical spectroscopy method.

Poly(methyl methacrylate) composites with size-selected silver nanoparticles fabricated using cluster beam technique

“…An extinction spectrum of viscous PMMA with as‐deposited silver clusters is shown in Figure demonstrating two overlapping bands with maxima at wavelengths of 378 and 465 nm. The first band at 378 nm is assigned to LSPR on individual Ag NPs . Nature of the second band at the higher wavelength is not completely clear.…”

“…One of them can be the use of the PMMA films with silver clusters as plasmonic transducers for biosensing. With the methodology on incubation of proteins on individual clusters, which is developed elsewhere, and partial immersion of Ag NPs into PMMA securing high adhesion, very stable and resistant against wet chemistry transducers can be developed.…”

“…The first band at 378 nm is assigned to LSPR on individual Ag NPs. 38 Nature of the second band at the higher wavelength is not completely clear. However, in an earlier series of experiments on cluster deposition it was found that extinction efficiency of this band gradually decreases with lowering the cluster surface coverage.…”

Charge states of size-selected silver nanoparticles produced by magnetron sputtering

“…In particular, charge states are essential for NP deposition on surfaces functionalized with either positive or negative net charges. For example, negatively charged Ag NCs were coupled to positively charged amine groups formed on quartz surface, thus, promoting formation of reliable optical transducers for biosening (Fojan et al 2015). Modulation of electrostatic potential in polymeric grooves produced with nanoscale lithography allowed to push limits in precise positioning of NPs and achieve formation of 1D NP arrays (Chen et al 2017).…”

The Development of Smart, Multi-Responsive Core@Shell Composite Nanoparticles

“…Recent research efforts have explored NPs having complex compositions with controllable sizes and morphologies. Special attention has been given to metal NPs for use as optical materials (i.e., using palladium [1,2], silver [3][4][5][6][7][8][9][10][11][12], copper [13][14][15][16][17][18], and particularly gold [19][20][21][22][23][24][25][26][27][28][29][30][31]). This is due to the ease of fabrication of these metal nanoparticles and their unique physical properties [32][33][34], such as the ability to absorb or scatter light [25,35,36].…”