Versatile core–shell magnetic fluorescent mesoporous microspheres for multilevel latent fingerprints magneto‐optic information recognition

Abstract

Latent fingerprints are extremely vital for personal identification and criminal investigation, and potential information recognition techniques have been widely used in the fields of information and communication electronics. Although physical powder dusting methods have been frequently employed to develop latent fingerprints and most of them are carried out by using single component powders of micron‐sized fluorescent particles, magnetic powders, or metal particles, there is still an enormous challenge in producing high‐resolution image of latent fingerprints at different backgrounds or substrates. Herein, a novel and effective nanoimpregnation method is developed to synthesize bifunctional magnetic fluorescent mesoporous microspheres for latent fingerprints visualization by growth of mesoporous silica (mesoSiO2) on magical Fe3O4 core and then deposition of fluorescent YVO4:Eu3+ nanoparticles in the mesopores. The obtained Fe3O4@mesoSiO2@YVO4:Eu3+ microspheres possess spatially isolated magnetic core and fluorescent shell which were insulated by mesoporous silica layer. Due to their small particle size of submicrometer scale, high magnetization and low magnetic remanence as well as the combined magnetic and fluorescent properties, the microspheres show superior performance in visual latent fingerprint recognition with high contrast, high anti‐interference, and sensitivity as well as good retention on multifarious substrates regardless of surface permeability, roughness, refraction, colorfulness, and background fluorescence interference, and it makes them ideal candidates for practical application in fingerprint visualization and even magneto‐optic information storage.

Mesoporous Silica Nanoparticles‐Based Nanoplatforms: Basic Construction, Current State, and Emerging Applications in Anticancer Therapeutics

“…[ 88 ] The method used superparamagnetic Fe 3 O 4 nanoparticles as magnetic cores, outer mesoporous silica as confinement nanoreactors, and uses capillary force to introduce YVO4:Eu 3+ precursors into mesoporous channels. [ 89 ] Then, the fluorescent nanoparticles were grown in situ in the pores by calcination to form functionalized magnetic fluorescent microspheres with core–shell structure (Fe 3 O 4 @mesoSiO 2 @YVO4:Eu 3+ ). The silica layer can spatially quench the fluorescence of the YVO4:Eu 3+ fluorescent shell layer by the Fe 3 O 4 magnetic core, effectively enhancing the luminescence performance in practical applications.…”

“…The silica layer can spatially quench the fluorescence of the YVO4:Eu 3+ fluorescent shell layer by the Fe 3 O 4 magnetic core, effectively enhancing the luminescence performance in practical applications. In addition to magnetic Fe as the core, [89] there are numerous studies using Au [90][91][92] and other materials [93,94] as the core to construct coreshell MSNs.…”

From nanomaterials to macromolecules: Innovative technologies for latent fingerprint development

“…The images presented low background interference, high contrast, and clear detail features of three levels, indicating promising application in personal identification. Yu et al (2022) have introduced a middle layer of mesoporous SiO 2 between the magnetic core (Fe 3 O 4 ) and the fluorescent YVO 4 :Eu 3+ shell to enhance the nanocomposite interface interaction aiming at obtaining superior performance in latent fingermark development. By using the Fe 3 O 4 @mesoSiO 2 @YVO 4 :Eu 3+ microspheres as developers, distinctive ridge characteristics of fingerprints on various substrates were observed and photographed under 254 nm light, and all three levels of fingerprint features could be clearly visible, Figure 8.…”

“…Excitation by ultraviolet lamp; and (c) images of latent fingerprints developed by Fe 3 O 4 @mesoSiO 2 @YVO 4 :Eu 3+ microspheres on practical applications: (i) and (ii) diverse regions of paper cup, (iii) coin, (iv) shopping receipt, (v) credit card, and (vi) paper currency. Adapted from Yu et al (2022) with permission of Elsevier…”

“…Excitation by ultraviolet lamp; and (c) images of latent fingerprints developed by Fe 3 O 4 @mesoSiO 2 @YVO 4 :Eu 3+ microspheres on practical applications: (i) and (ii) diverse regions of paper cup, (iii) coin, (iv) shopping receipt, (v) credit card, and (vi) paper currency. Adapted from Yu et al (2022) (Ramotowski, 2021). The principle and the reaction for this method have been well studied and consists in the selective polymerization reaction of gaseous ethyl-2-cyanoacrylate ester onto a surface containing a fingermark, resulting in a white fingerprint pattern (Wargacki et al, 2007;Chen et al, 2018).…”