Article pubs.acs.org/JPCC
Ultrasensitive Surface Acoustic Wave Detection of Collective Plasmonic Heating by Close-Packed Colloidal Gold Nanoparticles Arrays Chi-Shun Chiu,† Hung-Ying Chen,† Chun-Fang Hsiao, Meng-Hsien Lin, and Shangjr Gwo* Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan S Supporting Information *
ABSTRACT: A novel electrical detection method based on surface acoustic wave (SAW) is introduced to investigate the heat generation from a two-dimensional (2D) or three-dimensional (3D) close-packed gold nanoparticle (AuNP) array exhibiting tunable collective surface plasmon resonance (CSPR). We have found that the SAW sensor can detect the CSPR-induced photothermal heating effect. The conversion of absorbed light around the CSPR frequency into heat and subsequent transfer from the AuNP array to the lithium niobate (LiNbO3) substrate allows a dual delay-line SAW system to dynamically measure the resonant frequency change of the SAW oscillator coated with a 2D or 3D AuNP array. The experimental findings indicate that SAW detection provides an ultrasensitive (detection limit of temperature change
