Surface plasmon resonances of protein-conjugated gold nanoparticles on graphitic substrates

Abstract

We present theoretical calculations for the absorption properties of protein-coated gold nanoparticles on graphene and graphite substrates. As the substrate is far away from nanoparticles, numerical results show that the number of protein bovine serum molecules molecules aggregating on gold surfaces can be quantitatively determined for gold nanoparticles with arbitrary size by means of the Mie theory and the absorption spectra. The presence of graphitic substrate near protein-conjugated gold nanoparticles substantially enhances the red shift of the surface plasmon resonances of the nanoparticles. Our findings show that graphene and graphite provide the same absorption band when the distance between the nanoparticles and the substrate is large. However at shorter distances, the resonant wavelength peak of graphene-particle system differs from that of graphite-particle system. Furthermore, the influence of the chemical potential of graphene on the optical spectra is also investigated.

Cooperative nanoparticle self-assembly and photothermal heating in a flexible plasmonic metamaterial

“…5, we perform with an incident beam having diameter of 4 mm, F p ¼ 2.3 Â 10 À3 , and I ¼ 30.4 mW mm À2 . According to effective medium approximations, 24,25 an effective dielectric function of the metamaterials is 3 eff ¼ 3 f + F p 3 p , here 3 f and 3 f being the dielectric function of the aramid ber 5 and gold nanoparticles, 26 respectively. We assume that the presence of nanoparticles does not change the packing fraction and macroscopic structure of the aramid ber.…”

Optical Properties of Silver Nanowires Conjugated with Protein

“…BSA proteins are vehicle for delivering nanostructures to localtions of unhealthy cells [7,8]. Coating BSA on metallic nanoparticles can stabilize them and avoid aggregation of nanoparticles [9]. Biological configuration and physical properties of BSA protein dramatically vary with environmental changes [10].…”

“…Therefore, we can observe a conjugation between protein BSA and silver nanowires. However, protein BSA cannot cover 100 % surface of metallic nanostructures because of repulsive Coulomb force [9,10].…”

Methodologies for “Wiring” Redox Proteins/Enzymes to Electrode Surfaces

“…Regardless of whether proteins or enzymes are redox‐active or not, the analytical study and commercial utilization of such biomolecules is aided by such immobilization methodologies. For example, surface plasmon resonance (SPR) detection of drug molecule binding is inherently reliant on the attachment of proteins or enzymes onto sensor chips or nanoparticles . In industrial catalysis, the localization of enzymes on the surface of a solid support can also help overcome high operation costs, improving the ease of separation of enzyme from product, the lifetime and reusability of the enzyme, and potentially enhancing the thermostability .…”