A comprehensive review on the detection of latent fingermarks using carbon dots

Fingermarks are one of the oldest, reliable, and universally accepted evidence found on the crime scene. They can be used to link suspect with scene of crime and weapon of offence. Fingermarks are frequently used to investigate criminal cases and identify missing persons and criminals. Conventional methods such as cyanoacrylate fuming, iodine fuming, ninhydrin, silver nitrate, small particle reagent, and powder dusting are routinely used to detect and develop latent fingermarks on various surfaces of forensic importance. However, these methods suffer several limitations including poor contrast, low sensitivity, background interference, and low specificity. To overcome these limitations, nowadays, nanoparticles have gained importance in the development of latent fingermarks. In this review, we focus on the carbon dots (CD's) nanomaterial for the development of latent fingermarks. CD’s have superior fluorescence performance, color tuneability, and low synthesis cost and are non-toxic. The color and intensity of luminescence of CD's depend on its morphology and synthesis method. CD's can be used either in solid or solution form to develop latent fingermarks on the various porous and nonporous surfaces. CD’s are potentially a good candidate to develop latent fingermarks on wide range of porous and nonporous items of forensic importance. The fingerprints developed with CD’s show excellent contrast and resolution. Their small size, biocompatibility, facile and low-cost synthesis, and color tuneability can be successfully utilized to overcome the limitations of the conventional methods.