High Spatial Resolution Ion Imaging by Focused Electron-Beam Excitation with Nanometric Thin Sensor Substrate

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Light-addressable potentiometric sensors (LAPS) are established for ion sensing.
• Improving spatial resolution in LAPS systems remains a challenge.
• Electron beam excitation offers potential for enhanced imaging capabilities.

Purpose of the Study:

• To develop a high spatially-resolved ion-imaging system using focused electron beam excitation.
• To investigate the feasibility of electron beam excitation for pH measurement.
• To achieve superior spatial resolution compared to existing LAPS technologies.

Main Methods:

• Designed a nanometric thin sensor substrate to enhance spatial resolution.
• Utilized a focused electron beam as the excitation source, analogous to LAPS.
• Evaluated spatial resolution using a photoresist on the ion-sensor substrate.

Main Results:

• Achieved a Nernstian-like pH response with 53.83 mV/pH sensitivity.
• Demonstrated a pH linearity of 96.15%.
• Obtained a spatial resolution of 216 nm.

Conclusions:

• The developed electron beam-based system offers significantly higher spatial resolution than traditional LAPS.
• This technology advances high-resolution ion imaging and sensing capabilities.
• The nanometric thin sensor substrate is crucial for achieving enhanced spatial resolution.