Label-free transducers are of great interest for biomedical applications. Among those transducers surface plasmon resonance (SPR) is of widespread use already. An advantage of this technique is its use of a metal surface (often gold), to which surface immobilization via a thiol group is rather easy. However, SPR systems often times have a large footprint, which renders them unfeasible for point-of-care applications. A more compact alternative are label-free sensors based on photonic crystal slabs (PCS) [1]. These are commonly one-dimensionally structured waveguides, with the periodicity of the structure in the nanometer range. The waveguide consists of a high refractive index dielectric. In order to functionalize to the dielectric a more elaborate approach consisting of several successive steps is needed [2]. Titanium dioxide is a dielectric, which is often used as the waveguide. Further, we have shown that gold particles can be grown on titanium dioxide, when exposed to UV light [3]. In this internship we want to use this approach to grow structured nanoclustered gold on a PCS and analyze its optical properties. Further, we want to investigate whether a functionalization via a thiol functional group is feasible and whether biosensing is possible using this route.
References:
[1] F. A. Kraft et al., Biosensors, vol. 13, no. 7, p. 687, Jun. 2023
[2] F. A. Kraft et al., IEEE J. Flex. Electron., vol. 2, no. 2, pp. 136–144, Mar. 2023
[3] S. Veziroglu et al., ACS Appl. Mater. Interfaces, vol. 12, no. 13, pp. 14983-14992, Feb. 2020
