Plasmonic Gold Nanohole Arrays for Surface-Enhanced Raman Scattering Biosensing

Gold nanohole arrays can serve as promising substrates for construction of surface-enhanced Raman scattering (SERS) biosensors. Gold nanohole arrays support tunable localized surface plasmon resonance (LSPR) and propagating surface plasmon polariton (SPP). However, it is a great challenge to optimize their performance due to coexistence of LSPR and SPP. Here, finite difference time domain (FDTD) simulation is used in combination with measured transmission and reflection to discern which resonance mode leads to the electromagnetic field enhancement. The SERS peak signal intensity has been mapped with the nanohole size, which shows that the “gap” between neighboring nanoholes in the array pattern and the absorption play an important role in SERS enhancement. Optimization of hole size and pitch is necessary for development of nanohole array based SERS biosensors.