FOLIC ACID GRAFTING TO Ag
NANOCLUSTERS-SILICA THIN FILMS
S. Ferraris, S. Perero, E. Vernè, L. Rimondini, E.
Battistella and M. Ferraris
Cancer cells differ from heathy one for
 growth control,
THE PROBLEM
 morphology,
 cell-to-cell interactions,
 membrane properties,
CANCER CELLS 
 cytoskeletal structure,
RAPID DIVISION 
FOLIC ACID NEED
 protein
secretion,
Cancer cells detection at the FOR DNA SYNTHESIS
early developement stage.
 vascularization
 gene expression
 …
FA
Ag
Ag
FA
Ag
Ag
FA
Ag
Silver nanoclusters-silica
composites thin films
Absorbance [a.u]
AIM of THE WORK
Characteristic SPR
absorption
New SPR
absorption
Wavelength [nm]
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
THE SILVER NANOCLUSTERS-SILICA FILM
SUBSTRATE
SUBSTRATE
Ar
Ar
SILVER NANOCLUSTERS-SILICA LAYER
SILICA
Ag
THE SILVER NANOCLUSTERS-SILICA FILM
AS DEPOSITED
TT 450°C
SPR absorption
SPR absorption
100 nm
100 nm
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
THE GRAFTING PROCEDURE
Surface pre-treatment  cleaning and hydroxyls exposition
Acetone and water washings
Ag
Silanization
Amino-group
FA
APTES
Ag
FA
Folic Acid (FA) Grafting
Si
Ag
=
APTES
Ag
3-aminopropyltriethoxysilane (APTES)
Ag
Ag
OH
Functional group
FA
Si
NH2
APTES
NH2
OH
OH
FA
DCC
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
Ag
Ag Chemistry
Ag
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials
and
Physics
SILANIZATION
AS DEPOSITED
90
O
C
Si
Ag
N
a
XPS survey analysis
NH2
70
Atomic %
60
NH2
50
Washed
Element
Washed
Washed
47,6
40,3
O
57,5
Silanized
46,6
28,2
20
35,5
C
17,3
28,1
10
17,8
17,4
Si
22,3
18,4
Ag
3
2,4
N
0
4,5
40
30
6,3
0
0
4,4
AsDep
2,4
TT450
b
Atomic %
Silanized
Counts
Counts
Element
Contact angle [°]
80
XPS survey
analysis
TT 450°C
Silanized
S. Ferraris, S. Perero,
E. Vernè, E. Battistella, L. Rimondini; M. FerrarisBinding
“Surface
functionalization
Energy
[eV]
Binding Energy [eV]
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
FOLIC ACID GRAFTING
AS DEPOSITED
G0002_1.SPE:
G006C9_1.SPE:
2010 Feb 3 Al mono 25.6 W 100.0 µ 45.0° 23.50 eV
2010 Feb 3 Al mono 25.6 W 100.0 µ 45.0° 23.50 eV
N1s/Area1/1 (BKG_L)
C1s/Area1/1 (BKG_S)
TT 450°C
H0002_1.SPE:
Polite
H0002_1.SPE:
Politecnico
2010 Feb 3 Al mono 25.6 W 100.0 µ 45.0° 23.50 eV
2.6197e+002 max
6.73 min
2010 Feb 3 Al mono 25.6 W 100.0 µ 45.0° 23.50 eV
1.3465e+003 max
6.73 min
N1s/Area1/1 (BKG_L)
C1s/Area1/1 (BKG_S)
Politecnico
Politecnico
3.37 min
3.03 min
3.5929e+002 max
1.2802e+003 max
XPS survey analysis
400
1400
NH2
350
1200
300
Element
47,6
40,3
34,6
O
C
NHCO
28,2
35,5
38,9
Si
17,8
COOH
17,4
NH2
14,8
Ag
6,3
4,4
3,8
N
0
2,4
c/s
200
150
600
400
100
200
50
0
-50
0
7,9
298
296
410
408
294
406
292 290
288
286 284
282
280
278
404
402
400
398
396
394
392
390
Binding Energy (eV)
Ag
Binding Energy (eV)
Si
Si
-200
412
NH
Ag
Ag
Washed
200
1000
C
NH2
Si
800
c/s
NHCO
800
c/s
Counts
1200
FA+DCC
250
Atomic %
250
Silanized
1000
Counts
Atomic %
C-C
Pos. Sep. %Area
Pos. Sep. 398.39
%Area 0.00 80.65
283.64 0.00 400.01
49.85 1.62 19.35
284.26 0.62 44.69
286.69 3.05 5.45
1400
286.41 2.77 10.32
Counts
O
%Area
%Area
78.10
58.42
21.90
31.26
c/s
Washed
300
Counts
Element
Pos.
Pos. Sep.
Sep.
398.32
283.64 0.00
0.00
399.93
284.73 1.62
1.09
H0002_1.SPE
H0002_1.SPE
XPS survey analysis
G0002_1.SPE
G006C9_1.SPE
600
Si
400
Ag
200
N
Silanized
C-C
FA+DCC
57,5
46,6
NHCO
37,4
17,3
28,1
NHCO
41,4
22,3
18,4
14,7
3
2,4
0,8
0
4,5
5,8
150
100
50
0
NH2
0
COOH
-200
Ag
Ag
298
412
296
410
294
408
292
406 288
404 286
402 284
400 282
398 280
396 278
394
290
Binding Energy
(eV) Energy (eV)
Binding
392
S. Ferraris, S. Perero,
E. Vernè,
E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
BindingEnergy
Energy[eV]
[eV]
Binding
Energy
Binding
Energy
[eV] [eV]
Binding
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
390
ELISA TEST (*)
SECONDARY ANTIBODY (Rabbit
polyclonal to Mouse IgG (HRP) )
PRIMARY ANTIBODY
(FOLATE 8/33)
FA
Ag
Ag
FA
Ag
Ag
FA
Ag
(*) Eastern Piedmont University A. Avogadro
REACTION WITH CROMOGENEOUS
COMPOUND AND UVMEASUREMENT OF ABSORBANCE
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
Folic acid grafted Agnanoclusters-silica thin
films are able to selectively
bind the proper antibody
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization
of Ag-nanoclusters-silica composite films for biosensing accepted to Materials Chemistry and
Physics
CONCLUSIONS …
 Silver nanoclusters-silica composite films have been
effectively silanized with 3-aminopropyltriethoxysilane
 Folic acid has been successfully grafted to silanized
films via carbodiimide activation
 The characteristic SPR absorption is maintained
after functionalization
 FA-functionalized films are
recognize the proper antibody
able
to
selectively
… AND FUTURE DEVELOPMENTS
 SPR
absorption measurement in presence of the
antibody will be performed in humid environment in
order to evaluate the shift due to selective binding
 Recognition experiment with marked healthy and
cancerous cells will be performed
Thanks!