Characterization of single 1.8-nm Au nanoparticle attachments on AFM tips for single sub-4-nm object pickup.
This paper presents a novel method for the attachment of a 1.8-nm Au nanoparticle (Au-NP) to the tip of an atomic force microscopy (AFM) probe through the application of a current-limited bias voltage. The resulting probe is capable of picking up individual objects at the sub-4-nm scale. We also discuss the mechanisms involved in the attachment of the Au-NP to the very apex of an AFM probe tip. The Au-NP-modified AFM tips were used to pick up individual 4-nm quantum dots (QDs) using a chemically functionalized method. Single QD blinking was reduced considerably on the Au-NP-modified AFM tip. The resulting AFM tips present an excellent platform for the manipulation of single protein molecules in the study of single protein-protein interactions.
Hui-Wen
HW
Cheng
Yuan-Chih
YC
Chang
Song-Nien
SN
Tang
Chi-Tsu
CT
Yuan
Jau
J
Tang
Department of Engineering and System Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan. fangang@ess.nthu.edu.tw.
Fan-Gang
FG
Tseng