Deepshikha - CEMI Presentation pps

 Optimization of process parameters to find out the best nanostructured conducting polyaniline in terms of conductivity and size..  Application of nanostructured conducting polyaniline

Presented By: Deepshikha Amity University

Noida

 Optimization of process parameters to find out the best nanostructured conducting polyaniline in terms of conductivity and size.

 Application of nanostructured conducting polyaniline to biosensors.

Conducting Polymer

A conductive polymer is an organic polymer semiconductor They provide pathways for electronic conduction by doping Common classes of organic conductive polymers include

(thiophene)s, Poly(aniline)s etc

Characteristics of Nanostructured

materials

dimension down to the nanometer range i.e within 1-100

nm

ratio of surface area to volume

mechanical, electronic, optical) in nano scale dimension from their bulk material

 Bio sensor is an analytical device which converts a biological response into readable signal

 Bio sensor comprises of three components: bioreceptor, transducer and detector

Advg of Nanostructured Conducting Polymers (NSCP) for Biosensor appl

 High Surface Area

 Unique optical, electronic and magnectic properties

 Bio-compatibility

 Dimensional compatibility with biomolecules.

 Film forming ability.

 Flexibility and processibility.

 Size, stability, morphology , conductivity and porosity of nanostructured conducting polymers(NSCP) can be

modified by changing reaction conditions.

 Unique π electron uni-dimensional conductivity- enhancing the electron transfer rate(ETR) , lowering the detection

potential and enhancing the stability of the enzyme

 Electrochemical switching depending upon pH and state of oxidation.

Polymerisation procedure

added

1-3 days for complete polymerization.

Effect of concentration of oxidizing agent on the properties of NSPANI

 Smallest size, uniform

size distribution and the

highest conductivity are

obtained when molar

PANI1 PANI2 PANI3 PANI4 0.2

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

803nm 806nm

789nm 778nm

PANI1

PANI3

PANI2 PANI4

Effect of concentration of monomer on

the properties of NSPANI

Smallest size, uniform

size distribution and

PANI2 PANI8 0.42

0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60 0.62

120 140 160 180 200 220 240

0.5 1.0 1.5 2.0 2.5 3.0

806nm

790nm PANI8

Effect of concentration of structure

directing agent on the properties of

NSPANI

Smallest size, uniform

size distribution and

PANI5 PANI2 PANI6 PANI7 0.40

0.45 0.50 0.55 0.60 0.65

0.5 1.0 1.5 2.0 2.5 3.0 3.5

795nm

801nm 806nm

PANI5 PANI7

PANI2 PANI6

Effect of size of soft microreactor on size

120 140 160 180 200 220 240

Optimum process conditions for

nanostructured conducting polyaniline

Cyclic Voltammetric studies of best

nanostructured conducting polyaniline

Cyclic voltammetry was the method

used for electrodeposition of the

NSPANI emeraldine salt (ES) onto ITO

from the aqueous dispersion of

nanoparticles

Main peaks A and B corresponding to

the

transformation of leucoemeraldine base

(LB) to ES and ES to pernigraniline salt

(PS), respectively

On the reverse scan, peaks B’ and A’

correspond to the conversion of PS to

ES

and ES to LB, respectively.

Small redox peak around +350 mV

(C and C’) is associated with the

formation of p-benzoquinone and

hydroquinone as a side product

-0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 -0.00010

-0.00005 0.00000 0.00005 0.00010

B' C' A'

Application of nanostructured conducting polyaniline to biosensors

Characterization of bioelectrode

 Marked decrease in the anodic and cathodic

peak current upon immobilization of

enzyme on NSPANI film which indicates

that enzyme has immobilised on NSPANI film

 Difference between the anodic and

cathodic peak potential is reduced on

deposition of NSPANI onto ITO

 This indicates the reversibility and

electrocatalytic activity of the electrode

which may facilitate the electron

conduction pathway between the

enzyme and electrode

-0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 -0.00015

-0.00010 -0.00005 0.00000 0.00005 0.00010 0.00015 0.00020

c

b a

Pictorial representation of synthesis of NSPANI,

Immobilization of enzyme and biochemical reaction at Enzyme/NSPANI/ITO bioelectrode

0 10 20 30 40 50 0.20

0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60

Photometric response study for the detection of analyte Sodium dodecyl sulphate

Aniline Enzyme

CONH CONH CONH

Film formation of NSPANI on ITO

Polymerization of aniline in the presence of soft microreactor OHC-(CH 2 )

3 -CHO

Glucose+O 2 Gluconic acid+H 2 O 2

H 2 O 2 +O-anisidine O-anisidine (Reduced) (Oxidised)

GoX/NSPANI

Photometric response studies of

glucose biosensor

The value of absorbance resulting from the

oxidized form of dye was found to be increasing

linearly in the range of 5 mM/l to 40 mM/l for

GoX/NSPANI where as bulk PANI exhibits

linearity between 5-20mM

GOx/NSPANI

Glucose + O 2 Gluconic acid + H 2 O 2

H 2 O 2 + O-anisidine (red) 2 H 2 O + O-anisidine

(oxidized)

0 10 20 30 40 50 0.20

0.25 0.30 0.35 0.40 0.45 0.50 0.55

Optical characteristics of various

Lower detection limit(mM/l)

GoX/bulk

PANI

natural structures and do not get

denatured

5.8 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.0 0.66

0.68 0.70 0.72 0.74 0.76 0.78

Effect of interference on GoX/NSPANI/ITO bioelectrode

The effect of interferents such as

uric acid(UA), sodium ascorbate(SA)

on the glucose measurement has

been studied.

The results indicate the negligible

effect of these interferants on the

Storage Stability

 GoX /NSPANI/ITO based optical biosensor

retains its 90% activity after 15 days

 The loss in the activity of biosensor is not

due to the denaturation of enzyme but it is

due to the poor adhesion of cast NSPANI film

on the ITO electrode.

Electrochemical response studies

-0.00005 0.00000 0.00005 0.00010

Photometric response studies of H 2 O 2 biosensor

The value of absorbance resulting from

the oxidized form of dye has been found

to be increasing linearly in the range of

Optical characteristics of various

Regression Coeficient

HRP/bulk

PANI

Storage stability

The stability of HRP/ NSPANI films along with bulk PANI have been found to be poor which can be explained by the degradation of PANI film by the oxidation reaction of H2O2

monomer, oxidant,SDA as well as dopant in order to achieve the best NSPANI with respect to size , conductivity as well as

electrocatalytic properties

polymerization causes a drastic change in the electrochemical properties.

range(1mM-50mM), fast response time (30 s)(photometric), negligible

interferent effect(0.1%) and low Km value(0.28)

stability of the sensor is needed to be carried out.

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

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