Abstract

Fingerprints are one of the crucial pieces of evidence in criminal investigations. As fingerprints are majorly found in latent form on the surface, it is necessary to develop those latent fingerprints appropriately without destroying them or leaving out any detail. There are plenty of methods for identifying hidden finger impressions. The powder dusting method, ninhydrin, iodine fuming, cyanoacrylate etc., are traditional methods. Though these procedures help to develop the latent fingerprints, they have some drawbacks such as sensitivity, low contrast, and selectivity as well as high toxicity. To overcome this inadequacy, advanced techniques have been developed using different chemicals and nanoparticles such as metal nanoparticles, fluorescent nanoparticles embedded with quantum dots, rare-earth upconversion nanoparticles etc. The fluorescent nanomaterials enhanced all three levels of fingerprints and provided the minute details of latent fingerprints. This review paper focuses on the role of fluorescence-based methods used for the enhancement of the latent fingerprint and their advantages over traditional methods. As compared to other approaches, fluorescent nanomaterials can obtain optimal contrast quality, enhancement, better sensitivity, and selectivity while exhibiting lower toxicity, less autofluorescence interference, and low background inference.

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