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Applications of Nanotechnology in Forensic Science Dr. Ian Turner


Introduction University of Derby, UK Head of Discipline, Dept.

of Forensic Science UG and PG provision,

nationally recognised Background in

Nanotechnology (PhD) in AFM of bacterial replisome at the University of Nottingham) and Forensic Science (MSc) at Kings College London


Introduction Science related to courts

Multi-disciplinary applied science

A wide range of roles in the criminal justice system

Governed by the Locard exchange principle

Biology

Chemistry

PhysicsLaw

Maths


DNA Profilin

g

Criminology

Environmental Science

Law

Stat

istics

Maths

Ballistics

Fingerpr

ints

AnthropologyEntomology

ToxicologyAnal

ytic

alCh

emis

try

Biology

Physics

FIRE

HAIRS & FIBRES

GLASS

PAINT

Palyno

logy

Microbiology

Document Analysis

FORENSIC SCIENCE?Drug

s

Expert Witness

Bloo

d

ExplosivesGENETICS

Criminal Mind


What is Forensic Science?“ When he wants it, wherever he touches, whatever he leaves, even

without consciousness, will serve as a silent witness against him his fingerprints or his footprints, but his hair, the fibres from his clothes, the glass he breaks, the tool mark he leaves, the paint he scratches, the blood or semen he deposits or collects. All of these and more, bear mute witness against him. This is evidence that does not forget. It is not confused by the excitement of the moment. It is not absent because human witnesses are. It is factual evidence. Physical evidence cannot be wrong, it cannot perjure itself, it cannot be wholly absent. Only human failure to find it, study and understand it, can diminish its value." Dr. Edmond Locard 1942. Crime investigation: physical evidence and the police laboratory. Interscience Publishers, Inc.: New York


Nanotechnology in Forensic Science


Forensic Nanotechnology


Fingerprints


Nanoparticles (Fingerprints) Nanoparticles made of gold

that measured only 16nm in diameter tagged with surface antibodies used to recognise and detect small proteins found in the immune system.

When attached to the nanoparticles the antibodies recognise the breakdown products (metabolities) of common drugs and cause a colour change.

The technique initially designed to detect cotinine a compound found in cigarettes allows forensic investigators to generate ‘life style intelligence’ about the fingerprints of the perpetrators of crime such if they are a smoker or drug user


Nanoparticles (Fingerprints) The Atomic Force

Microscope (AFM) is capable of imaging fingerprint ridges on polished brass substrates at an unprecedented level of detail. Localized elemental analysis (using

EDAX, coupled with SEM imaging) shows the presence of the constituents of salt in the initial deposits. Together with water and atmospheric oxygen these are capable of driving a surface corrosion process.

This process is sufficiently localized that it has the potential to generate a durable negative topographical image of the fingerprint.


Fingerprints on Tapes Nanoparticle suspension

designed for developing latent finger marks on the traditionally difficult adhesive surfaces.

Samples of adhesive surfaces are immersed into fluorescent nanoparticles of cadmium selenium (CdSe).

The resulting developed marks were fully visible in 15 minutes and resolved prints more effectively than more traditional chemical techniques such as gentian violet


Blood


Blood Aging Blood aging hard to compare

new and old stains Wanted to measure elasticity


Document Analysis AFM Tapping Mode In Air Done ‘blind’ Confirmed with Traditional Techniques

Line Crossing Events involving Ink ribbon and Ball point pen


Hair Analysis Hair Analysis – Cuticle Step Height

Height of cuticle at distal end is an important measurable quality of hair

AFM reveals more information than SEM/TEM

Need to consider how representative sample is


Toxicology It is often of interest

to discover if a perpetrator or victim of crime was under the influence of drugs or alcohol. One was of doing this is looking for the metabolites of drugs in the urine.

This study used a combination of microextraction by packed sorbent (MEPS) and direct analysis at real time (DART) Tof-MS. Which improved the speed of extracting the drug from the urine and rate of drug detection

It has a higher limit of detection (4ng/ml cocaine). This leads to the possibility to detect very low levels of drugs, days after consumption in a person’s urine.


Challenges

Aging Biological Fluids

Rapid Fibre Screening


References

Contact CardDr. Ian [email protected]@DocWithTheSocs+441332 59208

Strasser, S. et al. (2007) Age determination of blood spots in forensic medicine by force spectroscopy. Forensic Sci. Int. 170, 8-14

Legget, R. et al. (2007) “Intelligent” fingerprinting: simultaneous identification of drug metabolities and individuals by using antibody-functionalized nanoparticles. Angew. Chem. Int. Ed 46, 4100-4103

Wang, Y. F et al. (2009) Application of CdSe nanoparticle suspension for developing latent fingermarks on the sticky side of adhesives. Forensic Sci. Int. 185, 96-99

Kasas, S. et al. (2001) Examinations of line crossing by atomic force microscopy. Forensic Sci. Int. 119, 290-298

Jagerdeo, E. et al ( 2009) Screening of Cocaine and Its Metabolites in Human Urine Samples by Direct Analysis in Real-Time Source Coupled to Time-of-Flight Mass Spectrometry After Online Preconcentration Utilizing Microextraction by Packed Sorbent. Journal of the American Society for Mass Spectromet. 20, 891-899

Goodard, AJ et al (2010) High resolution imaging of latent fingerprints by localized corrosion on brass surfaces.. J Forensic Sci. 2010 Jan;55(1):58-65.

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