Multi-target-responsive AIE material for in situ visualization of level 3 features in latent fingerprints

Area of Science:

• Forensic Science
• Materials Science
• Chemistry

Background:

• Latent fingerprint (LFP) Level 3 features (ridge shape, pore size) are crucial for matching damaged prints.
• Current LFP developers primarily target lipids, often requiring mixed solvents and neglecting amino acids.
• LFP component degradation limits visualization of Level 3 features in diverse fingerprint states.

Purpose of the Study:

• Develop hydrophilic, multi-target-responsive aggregation-induced emission (AIE) materials.
• Advance forensic individual identification by improving LFP visualization.
• Enable reliable LFP analysis despite variations in secretion composition and degradation.

Main Methods:

• Designed a cationic amphipathic AIE material with -COOMe groups (AIE-COOMe).
• Utilized fluorescence assays and DFT calculations to assess AIE-COOMe's targeting capabilities.
• Investigated intermolecular forces (hydrogen bonding, hydrophobic, electrostatic) for AIE material anchoring.

Main Results:

• AIE-COOMe visualized multiple secretions (amino acids, proteins, lipids) in LFPs using aqueous solutions.
• Achieved accurate visualization of Level 3 features despite dynamic secretion composition.
• DFT revealed -COOMe groups enhance hydrogen bonding for amino acid targeting; hydrophobic/electrostatic forces drive lipid targeting.

Conclusions:

• Multiple intermolecular forces enable rapid AIE material anchoring to diverse LFP secretions.
• Overcame limitations of single-secretion-reliant methods for LFP recognition and imaging.
• Established a foundation for precise identification of fragmentary LFPs.