title: Tracking single quantum dot and its spectrum in free solution with controllable thermal diffusion suppression.
abstract: Thermal motions of semiconductor quantum dots (QDs) are suppressed on a dehydrated agarose-modified surface. The diffusion coefficients (D) of particles can be controlled by modifying the surface with an appropriate agarose concentration. The value of D is more than 100 times lower than the theoretical value when the dried agarose surface is made with an 8% agarose solution. This makes it possible to real-time record the diffusion process of single particles and single molecules in low-viscosity solution. A transmission grating installed in front of the charge-coupled device separates the QD fluorescence into the zeroth-order and first-order spectrum. Therefore, the spectrum of dynamic QDs is tracked on the modified surface. Tracking the dynamic QD spectral image is a promising method to explore the process of the molecular interactions in the physiological buffer.
authors.affiliation: Biomedical Engineering Center, Hunan University, Changsha, Hunan 410082, People's Republic of China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Li
authors.forename: Rui
authors.initials: R
authors.lastname: Han
authors.forename: Xianxin
authors.initials: X
authors.lastname: Meng
authors.forename: Hongwei
authors.initials: H
authors.lastname: Gai
authors.forename: Edward S
authors.initials: ES
authors.lastname: Yeung
mesh_terms: D004058:Diffusion; D008856:Microscopy, Fluorescence; D045663:Quantum Dots; D012685:Sepharose / Q000737:chemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D012685:Sepharose