An Approach to Ring Resonator Biosensing Assisted by Dielectrophoresis: Design, Simulation and Fabrication

Abstract

The combination of extreme miniaturization with a high sensitivity and the potential to be integrated in an array form on a chip has made silicon-based photonic microring resonators a very attractive research topic. As biosensors are approaching the nanoscale, analyte mass transfer and bonding kinetics have been ascribed as crucial factors that limit their performance. One solution may be a system that applies dielectrophoretic forces, in addition to microfluidics, to overcome the diffusion limits of conventional biosensors. Dielectrophoresis, which involves the migration of polarized dielectric particles in a non-uniform alternating electric field, has previously been successfully applied to achieve a 1000-fold improved detection efficiency in nanopore sensing and may significantly increase the sensitivity in microring resonator biosensing. In the current work, we designed microring resonators with integrated electrodes next to the sensor surface that may be used to explore the effect of dielectrophoresis. The chip design, including two different electrode configurations, electric field gradient simulations, and the fabrication process flow of a dielectrohoresis-enhanced microring resonator-based sensor, is presented in this paper. Finite element method (FEM) simulations calculated for both electrode configurations revealed ∇E2 values above 1017 V2m−3 around the sensing areas. This is comparable to electric field gradients previously reported for successful interactions with larger molecules, such as proteins and antibodies.

Editorial for the Special Issue on Biosensors and MEMS-Based Diagnostic Applications

“…Finite element method simulations were calculated for both electrode configurations around the sensing areas. The obtained results were comparable to the electric field gradients previously reported for successful interactions with larger molecules, such as proteins and antibodies [2]. Sardesai and coworkers reported on the design and electrochemical characterization of a spiral electrochemical notification coupled electrode platform for biosensing applications [3].…”

“…In total, nine papers are published in this Special Issue, covering biosensors and MEMS-based diagnostics applications [1][2][3][4][5][6][7][8][9]. In particular, Dou et al fabricated a wearable contact lens sensor for non-invasive continuous monitoring of intraocular pressure (IOP) [1].…”

“…The non-invasive IOP sensor proposed in this report exhibits high sensitivity and satisfactory stability, with promising potential in continuous IOP monitoring [1]. Henriksson et al proposed an approach to ring resonator biosensing assisted by dielectrophoresis, where they designed microring resonators with integrated electrodes next to the sensor surface, which may be used to explore the effect of dielectrophoresis [2]. The chip design was presented, which included two different electrode configurations, electric field gradient simulations, and the fabrication process flow for a dielectrohoresis-enhanced microring resonator-based sensor.…”

Dielectrophoresis: An Approach to Increase Sensitivity, Reduce Response Time and to Suppress Nonspecific Binding in Biosensors?

“…An approach to improve the transduction method of biosensors has been to utilize micro- and nano-scaled materials [ 4 ] such as nanomechanical systems [ 5 ], nanopore sensors [ 6 , 7 , 8 ], Nanowire field effect transistors NWFET’s [ 9 ], or surface-enhanced RAMAN [ 10 ]. Due to the miniaturization of the materials, surface properties and surface reactions gains importance allowing only few molecules to influence the inherent properties of the device such as refractive index [ 11 , 12 ], wettability [ 13 ], photoluminescence [ 14 ], or conductivity [ 15 ]. This enables highly sensitive and efficient transducers.…”

Functionalization of Oxide‐Free Silicon Surfaces for Biosensing Applications

“…The rapid development in semiconductor technology has also been captured by new miniaturized biosensors [1][2][3] whose sensitivity and performance have been significantly improved by micro-and nanotechnologies. Nano-biosensors benefit from an efficient transduction mechanism due to a high surface to volume ratio [4] and theoretical faster analyte diffusion attributed to a lower fractional dimension.…”