A Sensitivity-Enhanced Electrolyte-Gated Graphene Field-Effect Transistor Biosensor by Acoustic Tweezers

Abstract

Low-abundance biomolecule detection is very crucial in many biological and medical applications. In this paper, we present a novel electrolyte-gated graphene field-effect transistor (EGFET) biosensor consisting of acoustic tweezers to increase the sensitivity. The acoustic tweezers are based on a high-frequency bulk acoustic resonator with thousands of MHz, which has excellent ability to concentrate nanoparticles. The operating principle of the acoustic tweezers to concentrate biomolecules is analyzed and verified by experiments. After the actuation of acoustic tweezers for 10 min, the IgG molecules are accumulated onto the graphene. The sensitivities of the EGFET biosensor with accumulation and without accumulation are compared. As a result, the sensitivity of the graphene-based biosensor is remarkably increased using SMR as the biomolecule concentrator. Since the device has advantages such as miniaturized size, low reagent consumption, high sensitivity, and rapid detection, we expect it to be readily applied to many biological and medical applications.

Editorial for the Special Issue on MEMS and Microfluidic Devices for Analytical Chemistry and Biosensing

“…The extremely low abundance of biomolecules in most sensing applications is the most well-known challenge. With the aim of reaching ever lower bio-detection limits, Yan Chen et al [2] report on the development of an acoustic concentrator, named "acoustic tweezers", which uses high frequency longitudinal acoustic waves to promote the concentration of the target molecules in the detection area of an electrolyte-gated graphene field effect transistor. The effect of the acoustic tweezers was validated under the microscope by IgG labelled with green fluorescence, and by comparison of the FET response (Dirac point shift) with and without acoustic accumulation.…”