Plasmon theory

An appreciation of the physico- and electrochemical basis of SPR sensing [61,62] requires a basic understanding of total internal rehection (TIR), evanescent wave, and surface plasmon theory. Figures 7.3 and 7.4 illustrate the basis of the SPR-based sensor, Biacore. ... 

In analogy to the plasmon theory [58, 59] we use as a starting point transition matrix elements of the commutator between the Hamiltonian and the one-electron replacement operator which correspond to the extended Brillouin theorem ... 

In order to illustrate how Eq. (33) can be connected with the customary plasmon theory we find it particularly instructive to consider two cases ... 

We showed the existence conditions for volume plasmons in the framework of the free-electron model but a generalization for surface plasmons can also be made in the framework of other models. Since the plasmon theory can be derived for the RPA, the existence of a plasmon can easily be checked by the RPA calculations. In agreement with the general theory presented, the ab initio RPA calculations carried out on alkali metal clusters of the size presented in this work and of considerably larger sizes do not exhibit plasmon-like excitations. 

Alu, A. and Engheta, N. (2006) Theory of linear chains of metamaterial/plasmonic particles as subdiffraction optical nanotransmission lines. Physical Review B - Condensed Matter, 74, 205436. 

C tyroki J., Homola J., Lambeck P.V., Musa S., Hoekstra H.J.W.M., Harris R.D., Wilinson J.S., Usievich B., Lyndin N.M., Theory and modelling of optical waveguide sensors utilising surface plasmon resonance, Sens. andActuat. B 1999 54 66-73. 

J Ctyroky, J. Homola, P. V. Lambeck, S. Musa, H.J.W.M. Hoekstra, R.D. Harris, J.S. Wdkinson, B. Usievich, N.M. Lyndin, Theory and modelling of optical waveguide sensors utihsing surface plasmon resonance, Sensors and Actuators B 54, 66-73 (1999). 

Plasmon absorption of dispersions of coin metal fine particles like gold was often used to estimate the size of particles. The absorption peak can be calculated on the basis of Mie theory. However, this is not always true. The peak position can move, depending on not only the size of the particles but also the environment of the particles and the extent of aggregation of the particles. Thus, UV-Vis absorption is only used just for understanding the rough image of particle dispersions. 

Chitosan-stabilized Au NPs can be selectively synthesized on surfaces like poly (dimethylsiloxane) (PDMS) films using HAuC14 as precursor. The computation of surface plasmon bands (SPBs) based on Mie theory and experimental results indicates that the particles are partially coated by chitosan. The proposed mechanism implies that chitosan acts as a reducing/stabilizing agent. Furthermore, PDMS films patterned with chitosan could induce localized synthesis of gold nanoparticles in regions capped with chitosan only [110]. 

St Moores, A. and Goettmann, F. The plasmon band in noble metal nanoparticles an introduction to theory and applications , New J. Chem., 2006, 30, 1121-1132. 

IPPs are modified by the presence of a second interface, even tens of nanometers apart. The position of the Double Interface Plasmon Peak depends essentially on the distance between the two interfaces and is not shifted as the probe position is changed (Figure 3b), contrary to the single interface case. The 0.5 eV difference between experiment and theory in the peak position for abrupt interfaces is compatible with the existence of a SiO thin layer on each interface. More details will be given elsewhere [11]. Other studies have also been performed recently on grain boundaries [12, 13] and dislocations [14], helping to choose between various possible structures. 

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