Q-SAND: WHISPERING GALLERY MODE DETECTION SYSTEM FOR ULTRASENSITIVE AND LABEL FREE TESTING IN BIOTECHNOLOGY

Abstract

Quantum Dots, a type of nanocrystal, have been shown to emit light at a very precise wavelength. Quantum dots of approximately 5 nm in diameter have been conjugated to a silica microsphere and then coated with free silica, thus encasing the Quantum Dots in a small chamber surrounding the microsphere. This structure is analogous to a light globe under a lampshade. Just as one can change the nature of the lamplight by changing the lampshade, one can change the Quantum Dot emitted light by changing the surface of the microsphere. Since the scale is so small (each microsphere is about the size of a single bacterial cell), the amount and nature of the material needed to bind to the surface to eff..