Fluorescent‐Labeled Octasilsesquioxane Nanohybrids as Potential Materials for Latent Fingerprinting Detection

Abstract

The recent demand for fluorescent‐labeled materials (FLMs) in forensic security concepts such as latent fingerprints (LFs) that encode information for anti‐counterfeiting and encryption of confidential data makes necessary the development of building new and innovative materials. Here, novel FLMs based on polyhedral oligomeric silsesquioxanes (POSS) functionalized with fluorophores via “click” reactions have been successfully synthesized and fully characterized. A comprehensive study of their photophysical properties has displayed large Stokes's shift together with good photostability in all cases, fulfilling the fundamental requisites for any legible LF detection on various surfaces. The excellent performance of the hetero‐bifunctional FLM in the visualization of LF is emphasized by their legibility, selectivity, sensitivity and temporal photostability. In this study, development mechanisms have been proposed and the overall concept constitute a novel approach for vis‐à‐vis forensic investigations to trace an individual's identity.

Highly efficient latent fingerprint detection by eight-dansyl-functionalized octasilsesquioxane nanohybrids

“…S16,S17). This was in full agreement with previously reported data [8] for similar POSS nanohybrid containing only one dansyl chromophore. Thus, an intramolecular charge transfer (ICT) state (shorter lifetimes) and possible aggregates (longer lifetimes) could be the responsible of these two emissive lifetimes.…”

“…S=O × × × × H-N (amino acid)). [8,22,23] Moreover, enlarged areas showed whorl, bifurcation, and ridge ending (Fig. 3, right side), which fulfill the requirements for fingerprint identification.…”

“…A judicious balance of hydrophobic and π-π interactions have been recognized in previous reports for the application of FLMs in LF detection [8][9][10]. Accordingly, our FLMs were designed based on the combination of a Si-O-Si skeleton and multiple dansyl scaffolds.…”

“…1A). [8] We demonstrated that these cubic octameric frameworks (T8) with an adequate cage size (0.5-0.7 nm), exhibited high stability, excellent biocompatibility in the biological environment [9,10] and effectiveness for LF detection. Fingermark ridges and the interstitial space between them are narrow (ca.…”

Interpol review of fingermarks and other body impressions (2019 – 2022)

“…Preliminary/Pilot studies – Several compounds to be applied in solution were proposed to detect fingermarks on various substrates, mostly non-porous: AIE-active molecules or complexes [ 230 , 245 , [379] , [380] , [381] , [382] , [383] , [384] , [385] , [386] , [387] , [388] ], benzothiazole derivatives [ 389 ], conjugated cationic polymers in solution [ 390 ], di-aqua tris(thenoyltrifluoroacetonate) europium III complex [ 391 ], dye-doped amphiphilic conjugated polymer micelles [ 392 ], dye-doped octasilsesquioxane hybrids [ 393 , 394 ], phenolic ligands chelated with metal ions [ 395 ], sequential processing involving the lifting of fingermarks by a cellulose membrane followed by immersion in water or chemical imaging [ 218 ], tetraphene derivatives [ 396 ]. Other reagents or mechanisms were also proposed: deposition of metallic films (i.e., copper, chromium, and aluminium) using magnetron sputtering [ 397 ], soot from camphor [ 398 ], sublimation of 9-fluorenone under vacuum [ 399 ].…”