Technical Papers and Presentations

Plasmonic-based biosensors have emerged as a powerful, cost effective and portable platform for phatogen and biomarker detection. In particular, Localized Surface Plasmon Resonance (LSPR) based systems, which rely on resonance shift tracking, present high sensitivity, specificity and real time detection. Current approaches integrate the plasmonic sensors in microfluidic channels, providing a multiplexing platform where many different experiments can be run in parallel [1]. Although promising, the performance of such approach is strongly limited by the long experimental times imposed by the diffusion-limited transport of the species. Consequently, a large amount of them do not interact with the sensor, leading to long assay times and a waste of sample. In recent years, researchers have investigated a variety of approaches to solve this general and crucial issue, using optofluidics [2, 3] and electrokinetics effects [4].

Here, we present numerical simulations of the laser-induced heating of a single or array of gold nanoantennas which, in conjunction with an applied a.c. electric field, initiates rapid microscale fluid motion, termed electrothermoplasmonic (ETP) flow [5,6], and particle transport. The physics of the ETP flow mechanism is described by several coupled partial differential equations, which can be solved numerically using the COMSOL Multiphysics® software package. The numerical results are compared with experimental measurements and are also used to explore the influence of the different geometries for the nanoantennas array and the parameters of the external applied electric field. The conclusions can help in the future design of optimized lab-ona-chip devices.