Application Of Nano-Ag And Fe₃O₄@Ag Nanoeggs In Latent Fingermark Detection

No two individuals possess identical fingerprints.When a finger touches asurface, sweat and components within the sweat are trans-ferred to the surface, thusleaving a latent fingerprint. Fingerprint development is one of the most reliablemethod for personal identification, one of the most reliable material evidence for theexposure of crime. The tecnology of fingerprint development has been a perfect andripe professional methods and skill, but there remain a series of problems to be solved.A method which is health and safety, high selectivity and sensitivity, and hence arepotentially useful in a broader range of applications in the forensic research arena.Relying on the literature analysis, experimental analysis and comparativeanalysis, this paper summarizes common development method for latent fingerprints,and explore the synthesis、the application of nano-Ag and Fe3O4@Ag nanoegg withtwo groups of experiments.We found that compared with traditionalmethod,nanotechnology showed more feasibility and superiority in the developmentof fingerprint. This paper is divided into five parts:In the first part, introduction,mainly gives the history of technology of the latentfingerprint development and the development of nanotechnology.In the second part, we have summarized the advantages and disadvantages oftraditional development methods.In the third part, we have studied the synthesis、properties of nano-Ag andexplore the influence of the stability、tempareture、pH value and the size of particle onthe fingerprint development.In the fourth part, we have studied the synthesis、properties and the application ofFe3O4@Ag nanoeggs, explored the influence of the stability、pH value on thefingerprint development. The Fe3O4@Ag nanoeggs were characterized by scanningelectron microscopy, transmission electron microscopy, UV-vis spectrum andsuperconducting quantum interference device magnetometer, respectively. Theprepared Fe3O4@Ag nanoeggs possessed uniform size, improved monodispersity,stability against aggregation and high magnetization, which were utilized for thedetection of latent fingerprints deposited onto different surfaces. The experimental results showed that the latent fingerprints developed with the Fe3O4@Ag nanoeggspowders exhibited excellent ridge details with minimal background staining.In the fifth part, we have summarized the superiority of nanotechnology.In the last part, We hope that by modifying the magnetic nanoparticles with thefluorescent reagent or algal protein biological fluorescene, it can improve fluorescentsubstances, expanding the range of the using of Fe3O4@Ag nanoeggs in thecomplicated and difficult situation for latent fingerprint development.