Characterization of individual nano-objects with nanoprojectile-SIMS

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biophysics

Background:

• Individual nano-object analysis requires methods capable of detecting compositional variations.
• Existing techniques often struggle with isolating nano-objects for single-particle characterization.
• The development of specialized substrates is crucial for advancing nano-object analysis.

Purpose of the Study:

• To demonstrate the capability of event-by-event Secondary Ion Mass Spectrometry (SIMS) for individual nano-object characterization.
• To validate the use of a Nano-Assisted Laser Desorption/Ionization (NALDI™) plate as a suitable substrate for isolating nano-objects.
• To analyze the composition of individual bacteriophages (Qβ and M13) using this methodology.

Main Methods:

• Utilized event-by-event SIMS for high-resolution analysis of individual nano-objects.
• Employed a NALDI™ plate with a nanostructured surface for nano-object deposition and isolation.
• Performed Scanning Electron Microscopy (SEM) to verify the integrity of nano-objects on the substrate.

Main Results:

• Successfully isolated individual nano-objects, specifically Qβ and M13 bacteriophages, on the NALDI™ plate.
• Confirmed the preservation of phage integrity using SEM imaging.
• Obtained mass spectrometric data clearly identifying secondary ions from the phages, distinct from the substrate.

Conclusions:

• Event-by-event SIMS combined with NALDI™ plates is a powerful approach for characterizing individual nano-objects.
• The NALDI™ substrate effectively facilitates the isolation of nano-objects for single-particle analysis.
• This method allows for the detailed compositional analysis of nanometric biological entities like bacteriophages.