Hierarchical spiral-scan trajectory for efficient scanning ion conductance microscopy. (August 2019)

• Record Type: Journal Article
• Authors: Zhuang, Jian; Wang, Zhiwu; Liao, Xiaobo; Gao, Bingli; Cheng, Lei
• Is Part Of: Micron. Volume 123(2019)
• Publication Date: 2019-08
• Subjects: Scanning ion-conductance microscopy (SICM) -- Spiral-scan trajectory -- Raster trajectory -- Detecting the highest point -- Imaging rate; Microscopy -- Periodicals; Electron Probe Microanalysis -- Periodicals; Microscopy -- Periodicals; Microscopie -- Périodiques; Microscopy; Periodicals; 502.82
• DOI: 10.1016/j.micron.2019.102683
• Languages: English
• ISSNs: 0968-4328

Abstract

Highlights: A novel SICM scanning approach is proposed to effectively reduce the retract distance of conventional scanning modes. The spiral trajectory is used in this approach to rapidly detect the highest point of the sample in a layer-by-layer way. Theoretical imaging time and various factors that affect the imaging speed in the new method are analyzed, respectively. PDMS and cell samples were imaged by developed method, hopping mode and raster-based detecting, respectively. Abstract: Scanning ion conductance microscopy (SICM) is an emerging technique for non-contact, high-resolution topography imaging, especially suitable for live cells investigation in a physiological environment. Despite its rapid development, the extended acquisition time issues of its typical hopping/backstep scanning mode still restrict its application for more fields. Herein, we propose a novel SICM scanning approach to effectively reduce the retract distance of existing hopping/backstep mode. In this approach, the SICM probe first gradually descends in the z -direction. Then by using Archimedes spiral trajectory, which has the advantage of higher angular velocity due to its continuous and smooth trajectory, the probe rapidly detects the highest point of the sample in the xy -plane in a layer-by-layer way. Further, the maximum height that decides the retrace distance of pipet in the detected region can be quickly achieved, avoiding a huge retrace distance usually adopted in the existing methods without any prior knowledge (sample height and steepness in the scanning region). Therefore, this new scanning method can greatly reduce the imaging time by minimizing the retrace height of each measurement point. Theoretical analysis is conducted to compare the imaging time of traditional and new method. And various factors in the new method that affect the imaging speed are analyzed. In addition, PDMS (polydimethylsiloxane) and biological samples (C2C12 cells) were imaged by SICM that was operated in the hopping mode, raster-based detecting and developed method with a single-barrel pipet, respectively. The experimental results suggest that the new method has a faster imaging speed than conventional scanning modes but does not sacrifice the imaging quality.