High-Q in-plane resonance-mode cantilever bio/chemical sensor for real-time detection in liquids

Reported is an lateral-mode resonant cantilever sensor that features a much depressed liquid drag force, thereby, achieving a much higher quality factor of 249 in water and higher specific mass sensitivity in liquids, compared with traditional out-of-plane resonant cantilevers. With 8.8Hz/pg sensitivity calibrated by specific binding streptavidin-labled Dynabeads with the biotin-immobilized cantilever in Phosphate Buffered Saline (PBS) solution, specific-antibody immobilized cantilevers have real-time detected E. coli in PBS solution. Real-time detection of Hg
²⁺
ions in aqueous Hg(NO
₃
)
₂
is also carried out by using the sensing-group-modified cantilevers, resulting in a finer noise-limited resolution than 100ppb.