title: Single molecular stamping of a sub-10-nm colloidal quantum dot array.
abstract: We introduce a nanoscale stamping technique of sub-10-nm colloidal quantum dot (QD) arrays to highly localized areas of three-dimensional nanostructures using a quartz tuning fork employed as the stamp pad (the "Nano Stamp"). CdSe/ZnS core-shell nanoparticles with diameters of 9.8 nm were deposited on microfabricated silicon probe tips. The number of transferred QDs, which ranged from several thousands down to single molecular order (less than 10), was precisely controlled by adjusting the stamping depths and angles. The stamping areas were varied from 1.2 microm x 1.2 microm down to 30 nm x 30 nm. Using the Nano Stamp, QDs can be transferred to a variety of protruding nanostructures. The amount of particles transferred to the tip was assessed by fluorescence intensity measurements, and the number of particles was estimated by direct transmission electron microscopy (TEM) observation. Correlation between the fluorescence intensity and the observed stamping depth and the approaching angle of the tip was found, demonstrating the efficacy of our Nano Stamp technique.
authors.affiliation: Department of Biomedical Engineering and Microelectronics Research Center, The University of Texas at Austin, 10100 Burnet Road, J. J. Pickle Research Campus, Austin, Texas 78758, USA. hoshino@mail.utexas.edu
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hoshino
authors.forename: Travis C
authors.initials: TC
authors.lastname: Turner
authors.forename: Sunmin
authors.initials: S
authors.lastname: Kim
authors.forename: Ashwini
authors.initials: A
authors.lastname: Gopal
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhang
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D045663:Quantum Dots; D011791:Quartz / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D003102:Colloids; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; D011791:Quartz; C058667:cadmium selenide; C031238:zinc sulfide