Direct detection of label-free blood fingermarks by SECM imaging

Autor: Liang Zhao, Mi Shi, Meiqin Zhang, Hongjuan Wang, Lu Tian, Xiaohui Wang, Xueji Zhang
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Electrochemistry Communications, Vol 102, Iss, Pp 89-93 (2019)
ISSN: 1388-2481
Popis: A label-free strategy for imaging blood fingermarks (BFMs) on a hydrophobic poly(vinylidene difluoride) (PVDF) membrane has been developed using scanning electrochemical microscopy (SECM) in the surface interrogation (SI) mode. In this approach, hexaammineruthenium chloride ([Ru(NH3)6]Cl3) was chosen as a redox mediator to react chemically with the electroactive hemichrome (HC) present in the BFM ridge deposits but not in the furrow regions. This provides a sharp contrast of the current response at the tip of the electrode between ridges and furrows and results in an electrochemical image of the BFM with the high resolution required for personal identification. In addition, this approach has high sensitivity, with the ability to directly image latent BFMs deposited with 1000-fold diluted blood on PVDF membranes. Such marks cannot be detected by optical microscopy. Moreover, for the first time a commercial PVDF membrane was used instead of adhesive forensic tape to lift the BFMs from common glass and multicolored banknote surfaces, and the lifted BFMs could also be efficiently imaged by this electrochemical method. Keywords: Blood fingermarks, SECM, Label-free, Electrochemical image, Hemichrome
Databáze: OpenAIRE