Biosensors based on nanoparticles and molecular switches

在分子水平上对生物传感模体的研究为纳米颗粒技术和分子开关的创造提供了方向。我们一直在探索装饰着寡核苷酸的量子点(QD)，作为使用荧光共振能量转移(FRET)运行的生物传感器的基础，QD激发附近的一种染料，与双链DNA的形成有关。如何在量子点上构建有序取向的寡核苷酸探针薄膜，以设计FRET的荧光转导，同时避免非选择性吸附和量子点发射的不良环境猝灭，是一个基本的挑战。利用双光子激发、相关光谱和单分子检测技术，我们可以加深对固定在量子点上的寡核苷酸的动力学功能的理解，从而走向合理的纳米级生物传感器的设计。

Investigation of biosensing motifs at a molecular scale offers direction for the creation of nanoparticle technologies and molecular switches. We have been exploring quantum dots (QDs) decorated with oligonucleotides as the basis for biosensors that operate using fluorescence resonance energy transfer (FRET), where the QD excites a nearby dye that is associated with formation of double-stranded DNA. There are fundamental challenges in learning how to construct organized oriented films of oligonucleotide probes on QDs for the design of fluorescence transduction by FRET while avoiding non-selective adsorption and undesired environmental quenching of QD emission. Using two-photon excitation, correlation spectroscopy and single-molecule detection strategies, we can develop an understanding of the dynamic function of immobilized oligonucleotides on QDs so as to move to rational design of nanoscale biosensors.