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

量子点是纳米晶体的一种，已经被证明可以在非常精确的波长下发光。直径约5 nm的量子点被连接到二氧化硅微球上，然后包裹上游离的二氧化硅，从而将量子点包裹在微球周围的一个小房间中。这种结构类似于灯罩下的灯球体。正如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。由于规模如此之小(每个微球的大小约为一个细菌细胞的大小)，因此结合到表面以实现可检测的变化所需的材料的数量和性质也非常小，仅为几十个或数百个分子的数量级。本项目试图利用这一原理来创造一种新型的超灵敏探测器，可以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.