Characterization of single 1.8-nm Au nanoparticle attachments on AFM tips for single sub-4-nm object pickup
1 Department of Engineering and System Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
2 Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
3 Medical Image Technology Department, Industrial Technology Research Institute, 195, Section 4, Chung Hsing Road, Hsinchu 31040, Taiwan
4 Department of Physics, Chung Yuan Christian University, Chungli 32023, Taiwan
5 Research Center for Applied Sciences, Academia Sinica, 128, Section 2, Academia Road, Taipei 11529, Taiwan
Nanoscale Research Letters 2013, 8:482 doi:10.1186/1556-276X-8-482Published: 15 November 2013
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.