Thai researchers converted cassava peel into fluorescent carbon dots by 360 W microwave pyrolysis for nine minutes. The dots emitted blue light at 470 nm under 365 nm excitation with 31% quantum yield. Incorporated into small-particle reagent, they visualised latent-fingerprint ridges and minutiae on glass under UV. This is a limited-surface proof of concept, not a blind forensic validation.
Key findings
- The dots emitted at 470 nm under 365 nm excitation with 31.0% quantum yield. CDs-SPR produced clear ridges on glass, low background and rapid processing. The authors report comparable or enhanced minutiae visualisation and repeatability, but the abstract gives no mark count or blinded accuracy measure.
Why this matters globally
Latent-mark development on nonporous or wet surfaces needs high contrast. Biomass dots may lower cost and expand forensic options if standard comparisons show they preserve DNA and downstream evidence.
Thai researcher contribution
Mahidol University, Firstlabs, Princess Chulabhorn Science High School Pathum Thani and Mae Fah Luang University connected school and university researchers around a major Thai biomass resource for forensic materials.
Limitations to consider
Testing focused on glass, not diverse plastics, metals, coloured surfaces, aged, wet, bloody or contaminated marks. Donor/sample counts and comparators are unclear, and blinded scoring is not stated. Feedstock-batch variation, SPR chemical impacts and life cycle were not assessed.