Novel Safranin-Tinted Candida rugosa Lipase Nanoconjugates Reagent for Visualizing Latent Fingerprints on Stainless Steel Knives Immersed in a Natural Outdoor Pond

Abstract

Waterways are popular locations for the disposition of criminal evidence because the recovery of latent fingerprints from such evidence is difficult. Currently, small particle reagent is a method often used to visualize latent fingerprints containing carcinogenic and hazardous compounds. This study proposes an eco-friendly, safranin-tinted Candida rugosa lipase (triacylglycerol ester hydrolysis EC 3.1.1.3) with functionalized carbon nanotubes (CRL-MWCNTS/GA/SAF) as an alternative reagent to the small particle reagent. The CRL-MWCNTS/GA/SAF reagent was compared with the small particle reagent to visualize groomed, full fingerprints deposited on stainless steel knives which were immersed in a natural outdoor pond for 30 days. The quality of visualized fingerprints using the new reagent was similar (modified-Centre for Applied Science and Technology grade: 4; p > 0.05) to small particle reagent, even after 15 days of immersion. Despite the slight decrease in quality of visualized fingerprints using the CRL-MWCNTS/GA/SAF on the last three immersion periods, the fingerprints remained forensically identifiable (modified-Centre for Applied Science and Technology grade: 3). The possible chemical interactions that enabled successful visualization is also discussed. Thus, this novel reagent may provide a relatively greener alternative for the visualization of latent fingerprints on immersed non-porous objects.

Interpol review of fingermarks and other body impressions 2016–2019

“… Preliminary/Pilot studies : Several kinds of NPs in solution were proposed to detect fingermarks on various substrates (e.g., non-porous, semi-porous, adhesive side of tapes): C-dots ➭ FITC-functionalized [ 391 ], green-emitting [ 392 ], white-emitting [ 393 ], orange-emitting [ 394 ], nitrogen- and sulfur-doped [ 321 ], suspended in poly (vinyl alcohol) [ 395 ], sprayed in hydrochloride solution [ 396 ]; gold NPs ➭ functionalized with lysozyme-targeting aptamers [ 397 ], functionalized with antibodies (i.e., anti-lysozyme, anti-human IgG and anti-cotinine) to serve as tags for SERS chemical imaging [ 398 ]; nanophosphors ➭ NIR-emitting lanthanide-based [ 399 ], EDC/NHS-functionalized [ 400 ]; nanorods ➭ carboxyl-functionalized [ 401 ], antibody-functionalized [ 402 ]; QDs ➭ functionalized cadmium-based [ 403 ]; silica NPs ➭ methylene blue-doped [ 283 ], carbon-doped [ 326 ], FITC-doped silica NPs [ 404 ], fluorophores-doped [ 286 ], Nile red-doped [ 405 ]; silver NPs ➭ in-situ generated [ 406 ]; other NPs ➭ NIR-emitting polymer dots doped with NIN [ 407 ], AIE-based nanomaterials built on diphenylpyrimidinone and salicylideneamine [ 408 ], poly [p-phenylenevinylene] [ 409 ], functionalized carbon nanotubes [ 410 ]; Co 2 TiO 4 NPs [ 310 ], rare-earth-doped upconversion NPs [ 411 ], AIE-based heteroleptic iridium complexes [ 412 , 413 ], coronenediimide nanostructures [ 337 ], and antibody-functionalized polystyrene NPs applied to drug-spiked fingermarks [ 414 ]. It should be emphasized that several of these studies were conducted with an extremely low number of donors leaving fresh, sebum-rich fingermarks, or were carried out by dropping few microliters of solution directly on the fingermarks.…”

“… Preliminary/Pilot studies : Various approaches were proposed to detect fingermarks on cartridge cases or other metallic surfaces: molecular complexes composed of l -alanine and conventional amino acid reagents (i.e., DFO, IND, MTN, and NIN) applied to brass and fired cartridges [ 429 ]; co-electrodeposition of silver and copper particles in deep eutectic solvent (mix of choline chloride and ethylene glycol), the secretion residue acting as a mask [ 430 ]; gel-based electrolytes (calcium chloride and potassium permanganate) applied to stainless steel and aluminium [ 431 ]; deposition of potassium birnessite (oxide mineral of manganese) on unfired cartridges and flat metal surfaces, the secretion residue acting as a mask [ 432 ]; electrostatic adsorption using a modified portable high-low voltage self-discharge device, applied to unfired brass cartridges [ 433 ]; nanoconjugate composed of carbon nanotubes, Candida rugosa lipase and safranin, applied in suspension on immersed stainless steel knives [ 410 ]; SKP and SEM/EPMA imaging of latent and VMD-processed fingermarks on metallic surfaces [ 434 ]; ToF-SIMS applied to flat metallic surfaces [ 435 ]; modified VMD process involving the deposition of gold followed by zinc, ZnS, or ZnO on aluminium [ 436 ]; and in situ reduction of aryldiazonium gold (III) salts induced by human sweat, applied to flat metallic surfaces [ 437 ]. Metal corrosion : Cooper-Dunn et al.…”

“… Preliminary/Pilot studies : Functionalized carbon nanotubes applied to immersed stainless steel [ 410 ]. Practice-oriented or case-related studies : Using aluminium soda cans bearing fresh sebum-rich fingermarks and three different scenarios (i.e., sheltered and unsheltered winter environments, and forced insertion into snow), McCook et al.…”

Fluorescent variant of silica nanoparticle powder synthesised from rice husk for latent fingerprint development

“…The numbers of donors were in accordance with guidelines as recommended for a phase 1 project (three to five different donors for proof-of-concept investigation of novel fingerprint detection methods) by the International Fingerprint Research Group (IFRG) (2014). The guidelines however are not meant to be prescriptive as single donor is acceptable in this type of study (Azman et al 2018). The protocol of this study was approved by The Human Research Ethics Committee of USM and informed consent from the donors was obtained.…”

Relevant visualization technologies for latent fingerprints on wet objects and its challenges: a review

“…However, its efficacy for visualizing latent fingerprints on wet objects is yet to be explored. Currently, review of literature reveals only one study that explored the use of green biotechnological route for visualizing latent fingerprints (Azman et al 2018) on wet non-porous objects. Despite their successful attempt at visualizing latent fingerprints on immersed objects, the method appears tedious and laborious, requiring the use of three different solutions over the span of nine minutes of fingerprint visualization.…”