Facile fabrication of Al nanoparticle arrays with continuous tunable diameter and plasmonic band for UV-visible SERS detection

Al-based nanostructures have a huge potential for surface-enhanced Raman scattering (SERS) in area of life science, chemical and food safety because of its excellent plasmonic characteristics from UV to near-infrared ranges. By only controlling the deposited Al thickness onto the parabola-shaped alumina nanopores template, the Al nanoparticle arrays with tunable diameter from 55 nm to 94 nm and plasmonic bands ranging from 285 nm to 717 nm were obtained. With excitation at UV and visible plasmon resonance wavelength (325 nm, 633 nm), the experimental SERS enhancement factor (EF) reached 103 and relative standard deviation (RSD) below 10% on a large scale. Finite-difference time-domain (FDTD) simulations reveal electric field intensity and charge distribution of dipolar and quadrupolar plasmon mode. The simple and controllable fabrication strategy and superior SERS performance in UV-visible range make the Al nanoparticle arrays promising candidates for SERSbased sensor applications. And the method provides a new approach for developing an inexpensive, efficient, and mass-produced Al-based SERS active substrate.

Automated summary

Al-based nanostructures with tunable diameter and plasmonic bands ranging from 285 nm to 717 nm were obtained by controlling the deposited Al thickness. The experimental results showed high SERS enhancement factors (EF) and low relative standard deviation (RSD) under UV and visible plasmon resonance excitation. Finite-difference time-domain (FDTD) simulations revealed the electric field intensity and charge distribution of dipolar and quadrupolar plasmon modes. The simple and controllable fabrication strategy and superior SERS performance make the Al nanoparticle arrays promising candidates for SERS-based sensor applications and provide a new approach for developing inexpensive and mass-produced Al-based SERS active substrates.