Perpustakaan Digital ITB

Detection of a single or small amount of charges and molecules in biologically relevant aqueous solutions is a long-standing goal in analytical science and detection technology. Here we report on self-assembled nanooscillators for charge and molecular binding detections in aqueous solutions. Each nano-oscillator consists of a nanoparticle linked to a solid surface via a molecular tether. By applying an oscillating electric field normal to the surface, the nanoparticles oscillate, which is detected individually with ?0.1 nm accuracy by a plasmonic imaging technique. From the oscillation amplitude and phase, the charge of the nanoparticles is determined with a detection limit of ?0.18 electron charges along with the charge polarity. We further demonstrate the detection of molecular binding with the self-assembled nano-oscillators.