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
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
Knowledge of cleanroom work
Fabrication of nanostructured materials via a manual nanoimprint lithography process
Deposition knowledge
Understanding of waveguides and grating couplers
Functionalization routes
Label-free biosensing
Gold growth on titanium dioxide
Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Education and Culture Executive Agency (EACEA). Neither the European Union nor EACEA can be held responsible for them.
