Facilitating the pickup of individual DNA molecules by AFM nanomanipulation with tips mechanically worn on bare mica

Abstract

The tip is one of the critical factors to improve the efficiency in picking up individual DNA molecules from solid substrates based on atomic force microscope (AFM) nanomanipulation. We found that wearing AFM tips on certain solid substrates in advance to nanomanipulation operation would largely improve the pickup efficiency, which was ascribed to the increasing affinity of the tip to the DNA molecules along with the increase of the tip radius after wearing. It was demonstrated that bare mica was superior to APTES-modified mica to keep the tip clean while wearing, which was crucial for DNA pickup during AFM nanomanipulation.

Spatial Manipulation and Assembly of Nanoparticles by Atomic Force Microscopy Tip-Induced Dielectrophoresis

“…AFM offers excellent precision in positioning and manipulation, which allows users to image nanosamples during the manipulation process. However, typical AFMs have only a single probe tip as the end-effector, which leads to severely inefficient nanomanipulation. , In addition, contact-mode manipulation using a sharp, hard AFM probe might cause damage to samples and substrates. , …”

“…30,31 In addition, contact-mode manipulation using a sharp, hard AFM probe might cause damage to samples and substrates. 32,33 Previous researchers have combined several techniques to achieve versatile nanomanipulation. Researchers have investigated the assembly of nanomaterials to AFM probes or sharp tips using tip-induced DEP, 34−37 which amply demonstrated that the nanomanipulation based on tip-induced DEP is flexible, efficient, and highly precise.…”