Nanoparticles as fingermark sensors

Physical visualization and squalene-based scanning electrochemical microscopy imaging of latent fingerprints on PVDF membrane

“…Traditional fingerprint development methods including the powder dusting and iodine fuming are characterized by simplicity and rapidity, but they are limited to impermeable substrates and low resolution resulting from the damage to level 3 features. Nowadays, nanoparticles, [7][8][9] quantum dots, 10,11 and their composite materials [12][13][14] are widely used in LFP enhancement to improve the quality of fingerprint patterns. However, the signal amplification requirements of these synthetic materials need additional sample processing, which sometimes is not compatible with subsequent chemical analysis such as DNA profiling.…”

One-step synthesis of self-quenching-resistant carbon dot phosphors and their application in fingerprint identification and anti-counterfeiting

“…6,7 There are four major sources of the powders using in the dusting method, including metallic, magnetic, regular, and luminescent. 8 The metallic powders, which contain gold, silver, and lead elements, might be toxic and harmful to human health. [9][10][11] Regular powders consist of resinous polymers and colorants, which might increase the difficulty for fingerprint identification.…”

“…[9][10][11] Regular powders consist of resinous polymers and colorants, which might increase the difficulty for fingerprint identification. 8 In addition, magnetic powders include carbon black, aluminum flakes, and others. The size of these commercial powders was determined in the range of several micrometers, which is hard for identification of detailed fingerprint features, like sweat pores.…”

Construction, Mechanism, and Forensic Application of Green-Light-Excited Fluorescent Carbon Dots/Diatomite Composites

“…Overall permanence and high discrimination as two attributes of friction ridge skin pattern have been challenged and confirmed through more than a century of fingerprint identification practice, laying the foundation for scientific identification of individuals involved in crimes. − The possible presence of fingerprints created by friction ridge skin on fingers after touching a surface falls into two major categories depending on whether they can be seen with the naked eye: visible and latent fingerprints . The invisible nature of latent fingerprints makes it necessary for forensic investigators to develop them before collection and analysis. − In most cases, they are formed by the transfer of eccrine sweat and other substances picked up by fingers from friction ridges to a surface, dividing the surface into a fingerprint ridge area covered with transferred substances and a background area retaining properties of the surface. The fundamental of fingerprint development is to create a difference that can be recognized by the human eye or image sensors between these two areas.…”