Characterization of electrochemically visualized latent fingerprints on the steel substrates

The characterization of electrochemically visualized latent fingerprints on steel surfaces is demonstrated. Optimization of electrochemical conditions of deposited poly(neutral red) (PNR) films on stainless steel substrates, as well as cyclic voltammetry, electrochemical impedance spectroscopy, and ATR FTIR spectroscopy of PNR-modified substrates, was performed. The parameters of the visualization method (supporting electrolyte, monomer concentration, potential range, number of cycles) were gradually changed until the fingerprint was sufficiently visible. The repeatability of measurements under these conditions was especially important, thanks to which many visible fingerprints on steel substrates were successfully obtained. The electrochemical characterization consisted in comparing the redox properties of the metal surfaces themselves before and after the application of the fingerprints or the polymer film PNR. Experimental findings have shown that the use of latent fingerprint visualization is a simple, fast, efficient, and inexpensive method applicable to forensic evidence.

Automated summary

This study demonstrates the characterization of electrochemically visualized latent fingerprints on steel surfaces. By optimizing the electrochemical conditions and visualization parameters, visible fingerprints on steel substrates were successfully obtained. The experimental findings show that latent fingerprint visualization is a simple, fast, efficient, and inexpensive method applicable to forensic evidence.