Measuring nanoparticles in liquid with attogram resolution using a microfabricated glass suspended microchannel resonator

Abstract

The use of nanoparticles has been growing in various industrial fields, and concerns about their effects on health and the environment have been increasing. Hence, characterization techniques for nanoparticles are essential. Here, we present a silicon dioxide microfabricated suspended microchannel resonator (SMR) to measure the mass and concentration of nanoparticles in a liquid as they flow. We measured the mass detection limits of the device using laser Doppler vibrometry. This limit reached a minimum of 377 ag that correspond to a 34 nm diameter gold nanoparticle or a 243 nm diameter polystyrene particle, when sampled every 30 ms. We compared the fundamental limits of the measured data with an ideal noiseless measurement of the SMR. Finally, we measured the buoyant mass of gold nanoparticles in real-time as they flowed through the SMR.

Silicon-Based Suspended Microchannel Resonator Developed Using Au Thermal Diffusion Bonding for Mass Sensing of Biomaterials

“…M ICROELECTROMECHANICAL systems (MEMSs) have attracted great attention in the field of physical and chemical sensors [1], [2]. In addition, suspended microchannel resonators (SMRs) have been developed for sensing biomaterials because their resonance frequency is highly sensitive, thereby enabling the detection of nano/microscale materials [3], [4], [5]. Burg et al have reported an SMR with resonance frequency of 426.8 kHz, mass resolution of 2.7 × 10 −20 kg in 1 kHz bandwidth, and a quality factor of approximately 9000, where the device was surrounded by a vacuum and filled with nitrogen gas [6].…”