Latent Fingerprints Enhancement Using a Functional Composite of Fe₃O₄@SiO₂-Au

Abstract

A functional composite of Fe₃O₄@SiO₂-Au was prepared and used for latent fingerprint detection. Material characterization results confirmed the successful fabrication of the Fe₃O₄@SiO₂-Au composite. In latent fingerprint detection, the Fe₃O₄@SiO₂-Au composite provides a better performance than commercial copper powder and also gold nanoparticles. More importantly, the Fe₃O₄@SiO₂-Au composite can be used in both powder and suspension forms, and also for common surfaces including glass, polyethylene bags, and paper. The favorable pH range (2.0–5.0) for the compositein finger marks detection is much wider than that of the traditional multi-metal deposition method (pH ranging from 2.0 to 3.0). The mechanism for the Fe₃O₄@SiO₂-Au composite in fingerprint detection was explored and discussed. This study provides a favorable choice for a one-step deposition method for latent fingerprint detection.

Keywords:

• Au
• Composite
• Fe₃O₄
• Fingerprint
• Functional material

Acknowledgments

The authors are grateful for the financial support provided by Chongqing Key Natural Science Foundation (cstc2012jjB50011), the Fundamental Research Funds for the Central Universities (XDJK2009C013; No. XDJK2010C009), and the NNSF of China (51102200).