Q-Sand (TM): Whispering Gallery Mode Detection System For Ultrasensitive and Label Free Testing in Biotechnology.

量子点，一种量子点，已被证明能以非常精确的波长发光。直径约5nm的量子点已经与二氧化硅微球缀合，然后用游离二氧化硅涂覆，从而将量子点包封在围绕微球的小室中。这种结构类似于灯罩下的光地球仪。就像人们可以通过改变灯罩来改变灯光的性质一样，人们可以通过改变微球的表面来改变量子点发射的光。由于尺度如此之小（每个微球大约是单个细菌细胞的大小），因此结合到表面以实现可检测变化所需的材料的数量和性质也非常小，大约只有几十或几百个分子。该项目旨在利用这一原理来创建一类新的超灵敏检测器，可用于医疗诊断和生物传感等多种应用。

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 effect a detectable change is also very small, on the order of just of few tens or hundreds of molecules. This project seeks to exploit this principle to create a new class of ultra sensitive detector which can be used in many sorts of applications such as medical diagnostics and biosensing.