Graphene nano-electromechanical mass sensor with high resolution at room temperature

Area of Science:

• Nanotechnology
• Materials Science
• Mechanical Engineering

Background:

• Two-dimensional (2D) materials offer potential for nanomechanical mass sensing due to their unique properties.
• Surface contamination frequently impedes the application of 2D materials in high-precision sensing.
• Existing methods struggle with achieving sub-attogram resolution and stability.

Purpose of the Study:

• To develop a highly sensitive nanomechanical resonant mass sensor using 2D materials.
• To address the challenge of surface contamination in 2D material-based sensors.
• To demonstrate sub-attogram resolution for weighing minute particles.

Main Methods:

• Fabrication of a tri-layer graphene nanomechanical resonant sensor using a bottom-up approach.
• Application of Joule-heating for effective cleaning of the graphene membrane surface.
• Characterization of sensor performance via deposition of Chromium (Cr) metal using a stencil mask.

Main Results:

• Achieved sub-attogram resolution at room temperature.
• Demonstrated that Joule-heating significantly improves resonance frequency stability by cleaning the graphene surface.
• Verified the sensor's capability to weigh very small particles, such as large proteins and protein complexes.

Conclusions:

• The developed graphene nanomechanical sensor offers unprecedented mass resolution.
• Joule-heating is a viable method for surface decontamination, enhancing sensor performance.
• The sensor holds significant potential for applications in nanobiology and medicine for precise mass determination.