Development of Enzyme- and Protein-Functionalized Alginate Hydrogels with Luminol Catalytic Functionality for Use as...

Area of Science:

• Forensic Science
• Biomaterials
• Chemistry

Background:

• Forensic blood substitutes (FBS) are crucial for research and training in forensic science.
• A key feature of FBS is their ability to mimic latent bloodstains, which are invisible until enhanced.
• Common reagents like luminol are used to detect latent bloodstains through chemiluminescence.

Purpose of the Study:

• To develop and evaluate two alginate-based hydrogels as functional forensic blood substitutes.
• To assess the ability of these novel materials to catalyze luminol oxidation, mimicking whole blood.
• To compare the chemiluminescent properties of the developed FBS with whole blood standards.

Main Methods:

• Two alginate-based hydrogels were synthesized: one protein-based (AlgXHb) and one enzyme-based (AlgXHRP).
• Materials were characterized using UV-vis spectroscopy and rheology.
• Chemiluminescence was measured by reacting the FBS with luminol and comparing to bovine blood dilutions.

Main Results:

• Both AlgXHb and AlgXHRP produced luminol-induced chemiluminescence in film and microparticle forms.
• AlgXHb mimicked latent bloodstains comparable to a 1:1000 dilution, with a short half-life (∼17 s).
• AlgXHRP showed chemiluminescence similar to a 1:10,000 dilution, with a longer half-life (∼60 s).

Conclusions:

• The developed alginate-based hydrogels serve as effective forensic blood substitutes.
• AlgXHb and AlgXHRP successfully mimic latent bloodstains, offering varying reaction kinetics and intensities.
• These FBS provide valuable alternatives for on-scene luminol testing and training materials for forensic practitioners.