EXPLOSIVE DETECTOR POLYMERS

By – Neha Singh M.Tech (CST)

TNT

Explosives and its Classification

The Usual Suspects

EXPLOSIVE DETECTOR POLYMERS

Based on synthesized polymers which bind to

explosive molecules and give an amplified

signal upon detection.

A new technology based on this principle is

Amplifying florescent polymers (AFPs).

http://onlinelibrary.wiley.com/doi/10.1002/pat.3209/abstract

AMPLIFIED FLORESCENT POLYMERS (AFPS)

These are conjugated polymers.

They are used for nitro aromatics explosive detection.

The main AFPs are :

Poly (3-hexylthiophene) P3HT Poly(p-phenylenevinylenes) Polyacetylenes Poly [2-(3-thienyl) ethanol n-butoxy carbonylmethyl-

urethane] (PURET)

POLY (3-HEXYLTHIOPHENE) P3HT

It is a Polythiophene derivative. The thiophene molecules contain n-hexyl group

at 3- position . Mainly used for the detection of TNT.

POLY [2-(3-THIENYL) ETHANOL N-BUTOXY CARBONYLMETHYL-

URETHANE] (PURET)

PURET is also a substituted Polythiophene. It is generally used for the detection of DNT and

TNT. Its conductivity is approximately 1 S/cm.

POLY(P-PHENYLENEVINYLENES) PPVS

Poly (p-phenylenevinylenes) are diamagnetic

materials. Very low intrinsic electrical conductivity, of the

order of 10-13 S/cm. Alkoxy-substituted PPVs have much higher

conductivities.

PPV

POLYACETYLENES

They are used to detect the vapors of DNT. The most effective Polyacetylene derivative is

poly([1-phenyl-2-(4-trimethylsilylphenyl)]

acetylene)(PTMSDPA).

EXPLOSIVE DETECTION USING AMPLIFIED FLORESCENT POLYMERS

(AFPS) Nitro aromatic Explosives are electron deficient

compounds (electron acceptor). Conjugated polymers are electron donor. When a Nitro aromatic Explosives molecule

come in contact with conjugated polymer, it

binds to it and electron transfer occur.

electronsEXPLOSIVE POLYMER

Florescence can be observed when AFPs are irradiated with suitable wavelength of light.

Generally used wave length is 370 nm.

When a analyte bind to florescent molecule, it absorbs the excitation and quenching of florescence takes place.

Conventional fluorescence detection measures :

An increase or decrease in fluorescence

intensity.

Change in emission wavelength when a single

molecule of analyte interacts with a single

fluorophore.

Hence, florescence quenching of only a single

molecule takes place.

The FIDO Technology

Q. Zhou and T. M. Swager, J. Am. Chem. Soc., 1995, 117, 12593.

Q. Zhou and T. M. Swager, J. Am. Chem. Soc., 1995, 117, 12593.

FIDO Systems

Applications

People and vehicle screening

Environmental Screening

Underwater Screening

CONCLUSION

The amplifying fluorescent polymer-based sensor offers the potential of revolutionizing technology solution for landmine detection .

The AFP based sensor offer extraordinary sensitivity and good selectivity to target analytes specific to landmines.

They are small , low power consuming and easy to operate.