FOLIC ACID GRAFTING TO Ag
NANOCLUSTERS-SILICA THIN FILMS
S. Ferrarisa, S. Pereroa, E. Vernèa, L. Rimondinib, E.
Battistellab and M. Ferrarisa
a
Politecnico di Torino, Materials Science and Chemical
Engineering Department, Torino, Italy
b
Universita’ degli Studi del Piemonte Orientale "Amedeo
Avogadro“, Department of Medical Sciences, Novara, Italy
THE PROBLEM
Cancer cells differ from heathy one for
growth control,
morphology,
cell-to-cell interactions,
membrane properties,
cytoskeletal structure,
Cancer cells detection
at the early
developement stage.
protein secretion,
vascularization
gene expression
…
CANCER CELLS → RAPID DIVISION → FOLIC
ACID NEED FOR DNA SYNTHESIS
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
CO-SPUTTERING
SUBSTRATE
Ar
Ar
Ag
SILICA
SUBSTRATE
SILVER
NANOCLUSTERSNANOCLUSTERSSILICA LAYER
THE SILVER NANOCLUSTERS-SILICA FILM
AS DEPOSITED
TT 450°C
SPR absorption
SPR absorption
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
AS DEPOSITED
100 nm
TT 450°C
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
OH
Surface pre-treatment ⇒ cleaning and hydroxyls exposition
Acetone and water washings
Ag
Ag
Silanization
NH2
NH2
Functional group
=
Amino-group
Ag
FA
Folic Acid (FA) Grafting
Si
FA
Ag
3-aminopropyltriethoxysilane (APTES)
Ag
FA
Si
Ag
Ag
APTES
APTES
APTES
FA
DCC
OH
OH
Ag
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization of Agnanoclusters-silica composite films for biosensing accepted to Materials Chemistry and Physics
Ag
SILANIZATION
90
Contact angle [°]
80
70
60
50
Washed
40
Silanized
30
20
10
0
AsDep
TT450
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization of Agnanoclusters-silica composite films for biosensing accepted to Materials Chemistry and Physics
SILANIZATION
AS DEPOSITED
TT 450°C
XPS survey analysis
XPS survey analysis
Atomic %
Atomic %
Element
Washed
Silanized
Element
Washed
Silanized
O
47,6
40,3
O
57,5
46,6
C
28,2
35,5
C
17,3
28,1
Si
17,8
17,4
Si
22,3
18,4
Ag
6,3
4,4
Ag
3
2,4
N
0
2,4
N
0
4,5
SILANIZATION
AS DEPOSITED
TT 450°C
SILANIZATION
AS DEPOSITED
TT 450°C
a
b
NH2
Counts
Counts
NH2
Binding Energy [eV]
Binding Energy [eV]
SILANIZATION
AS DEPOSITED
TT 450°C
FOLIC ACID GRAFTING
AS DEPOSITED
TT 450°C
XPS survey analysis
XPS survey analysis
Atomic %
Atomic %
Element
Washed
Silanized
FA+DCC
Element
Washed
Silanized
FA+DCC
O
47,6
40,3
34,6
O
57,5
46,6
37,4
C
28,2
35,5
38,9
C
17,3
28,1
41,4
Si
17,8
17,4
14,8
Si
22,3
18,4
14,7
Ag
6,3
4,4
3,8
Ag
3
2,4
0,8
N
0
2,4
7,9
N
0
4,5
5,8
S. Ferraris, S. Perero, E. Vernè, E. Battistella, L. Rimondini; M. Ferraris “Surface functionalization of Agnanoclusters-silica composite films for biosensing accepted to Materials Chemistry and Physics
FOLIC ACID GRAFTING
AS DEPOSITED
TT 450°C
Pos. Sep.
283.64 0.00
284.73 1.09
286.41 2.77
1400
%Area
58.42
31.26
10.32
1400
1200
1200
C-C
1000
%Area
49.85
44.69
5.45
C-C
1000
Counts
NHCO
800
Counts
Pos. Sep.
283.64 0.00
284.26 0.62
286.69 3.05
600
NHCO
800
600
400
400
COOH
COOH
200
200
NH
NH2
0
NH2
0
-200
-200
298
296
294
292
290
288
286
284
282
280
298
278
Si
Binding Energy [eV]
Si
Ag
Ag
Ag
296
292
290
288
286
Binding Energy (eV)
284
282
Binding Energy [eV]
Si
Ag
294
Ag
Detailed analysis of carbon region
280
278
FOLIC ACID GRAFTING
AS DEPOSITED
TT 450°C
300
NH2
350
Pos. Sep. %Area
398.39 0.00 80.65
400.01 1.62 19.35
Pos. Sep. %Area
398.32 0.00 78.10
399.93 1.62 21.90
400
250
NH2
300
200
Counts
Counts
250
200
NHCO
150
150
NHCO
100
100
50
50
NH
0
NH2
0
NH2
-50
412
412
410
408
406
404
402
400
398
396
394
392
410
390
Si
Binding Energy [eV]
Si
Ag
Ag
Ag
408
406
404
402
400
398
Binding Energy (eV)
396
Binding Energy [eV]
Si
Ag
Ag
Detailed analysis of nitrogen region
394
392
390
FOLIC ACID GRAFTING
AS DEPOSITED
TT 450°C
ELISA TEST (*)
SECONDARY ANTIBODY (Rabbit
polyclonal to Mouse IgG (HRP) )
PRIMARY ANTIBODY
(FOLATE 8/33)
FA
Ag
Ag
FA
Ag
Ag
FA
Ag
REACTION WITH CROMOGENEOUS
COMPOUND AND UV-MEASUREMENT
OF ABSORBANCE
(*) Eastern Piedmont University A. Avogadro
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