Biosensors based on nanoparticles and molecular switches

在分子尺度上对生物传感基序的研究为纳米粒子技术和分子开关的创造提供了方向。我们一直在探索用寡核苷酸修饰的量子点（QDs）作为使用荧光共振能量转移（FRET）操作的生物传感器的基础，其中量子点激发与双链DNA形成相关的附近染料。如何在量子点上构建有组织的寡核苷酸探针取向膜，以设计FRET荧光转导，同时避免量子点发射的非选择性吸附和不希望的环境猝灭，这是一个根本性的挑战。利用双光子激发、相关光谱和单分子检测策略，我们可以了解固定化寡核苷酸在量子点上的动态功能，从而为合理设计纳米级生物传感器提供依据。

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.