Abstract

We present a simple method of fabricating blinking nanoparticles and their application as sensors and transducers for the detection of unlabeled molecules. Blinking nanoparticles were fabricated by depositing a thin metal film on one side of fluorescent nanoparticles using metal evaporation. The particles are then detached from the substrate by sonication. The fabrication process was explained schematically in Fig.1. The patterned nanoparticles emit fluorescence light only from one hemisphere since the light emission from the other is blocked by opaque metal coating. When patterned particles are suspended in liquid, they blink constantly due to the rotational Brownian motions of particles. The rotational diffusion coefficient given by equation (1) has the unit of time inverse and represents how fast the rotation of a

© 2003 Optical Society of America