FOLIC ACID GRAFTING TO Ag NANOCLUSTERS-SILICA THIN FILMS

FOLIC ACID GRAFTING TO Ag FOLIC ACID GRAFTING TO Ag NANOCLUSTERS-SILICA THIN NANOCLUSTERS-SILICA THIN

FILMSFILMSS. FerrarisS. Ferraris, S. Perero, E. Vernè, L. Rimondini, E. , S. Perero, E. Vernè, L. Rimondini, E.

Battistella and M. FerrarisBattistella and M. Ferraris

THE PROBLEMTHE PROBLEM

Cancer cells detection at the Cancer cells detection at the early developement stage.early developement stage.

Cancer cells differ from heathy one Cancer cells differ from heathy one forfor

growth control, growth control,

morphology, morphology,

cell-to-cell interactions,cell-to-cell interactions,

membrane properties, membrane properties,

cytoskeletal structure, cytoskeletal structure,

protein secretion, protein secretion,

vascularizationvascularization

gene expressiongene expression

… …

CANCER CELLS CANCER CELLS RAPID DIVISION RAPID DIVISION FOLIC ACID NEED FOLIC ACID NEED FOR DNA SYNTHESISFOR DNA SYNTHESIS

AIM of THE AIM of THE WORKWORK

Ag

Ag

Ag

Ag

Ag

Silver nanoclusters-Silver nanoclusters-silica composites thin silica composites thin

filmsfilms

FA FA FA

Ab

sorb

an

ce [

a.u

]Wavelength [nm]

Characteristic SPR absorption

New 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

SILICASILICA AgAg

ArAr ArAr

SUBSTRATESUBSTRATE

SUBSTRATESUBSTRATE

SILVER NANOCLUSTERS-SILICA LAYERSILVER NANOCLUSTERS-SILICA LAYER

THE SILVER NANOCLUSTERS-SILICA FILMTHE SILVER NANOCLUSTERS-SILICA FILM


SPR absorptionSPR absorption

SPR absorptionSPR absorption

THE SILVER NANOCLUSTERS-SILICA FILMTHE SILVER NANOCLUSTERS-SILICA FILM

AS DEPOSITEDAS DEPOSITED TT 450°CTT 450°C

100 nm 100 nm


Acetone and water washings

Surface pre-treatment cleaning and hydroxyls exposition

OHOH OH

Ag Ag Ag

THE GRAFTING PROCEDURETHE GRAFTING PROCEDURE

Silanization

3-aminopropyltriethoxysilane (APTES)

Functional group

=

Amino-groupAg

Ag

Ag

NH2

Si

NH2

Si

Folic Acid (FA) Grafting

DCC

FA

Ag

Ag

Ag

AP

TE

SFA

AP

TE

SFA

AP

TE

SFA


SILANIZATIONSILANIZATION

0

10

20

30

40

50

60

70

80

90

AsDep TT450

Co

nta

ct

an

gle

[°]

Washed

Silanized


Atomic %

2,40N

4,46,3Ag

17,417,8Si

35,528,2C

40,347,6O

SilanizedWashedElement

XPS survey analysisXPS survey analysis XPS survey analysisXPS survey analysis

Atomic %

4,50N

2,43Ag

18,422,3Si

28,117,3C

46,657,5O

SilanizedWashedElement

Cou

nts

Binding Energy [eV]

a

NH2

Cou

nts

Binding Energy [eV]

bNH2


FOLIC ACID GRAFTINGFOLIC ACID GRAFTING


Atomic %

7,92,40N

3,84,46,3Ag

14,817,417,8Si

38,935,528,2C

34,640,347,6O

FA+DCCSilanizedWashedElement

XPS survey analysisXPS survey analysis

Atomic %

5,84,50N

0,82,43Ag

14,718,422,3Si

41,428,117,3C

37,446,657,5O

FA+DCCSilanizedWashedElement

XPS survey analysisXPS survey analysis

NH

Si

NH2

Si

NH2

Si

Ag AgAg

Ag Ag

G006C9_1.SPE: Politecnico

2010 Feb 3 Al mono 25.6 W 100.0 µ 45.0° 23.50 eV 1.2802e+003 max 3.03 min

C1s/Area1/1 (BKG_S)

278280282284286288290292294296298-200

0

200

400

600

800

1000

1200

1400

G006C9_1.SPE

Binding Energy (eV)

c/s

Pos. Sep. %Area283.64 0.00 58.42284.73 1.09 31.26286.41 2.77 10.32

Cou

nts

Binding Energy [eV]

C-C

NHCO

COOH

H0002_1.SPE: Politecnico


C1s/Area1/1 (BKG_S)

278280282284286288290292294296298-200

0

200

400

600

800

1000

1200

1400

H0002_1.SPE

Binding Energy (eV)c/

s

Pos. Sep. %Area283.64 0.00 49.85284.26 0.62 44.69286.69 3.05 5.45

Binding Energy [eV]

Cou

nts

C-C

NHCO

COOH

G0002_1.SPE: Politecnico


N1s/Area1/1 (BKG_L)

390392394396398400402404406408410412

-50

0

50

100

150

200

250

300

350

400

G0002_1.SPE

Binding Energy (eV)

c/s

Pos. Sep. %Area398.32 0.00 78.10399.93 1.62 21.90

Cou

nts

Binding Energy [eV]

NH2

NHCO

H0002_1.SPE: Politecnico


N1s/Area1/1 (BKG_L)

390392394396398400402404406408410412

0

50

100

150

200

250

300H0002_1.SPE

Binding Energy (eV)

c/s

Pos. Sep. %Area398.39 0.00 80.65400.01 1.62 19.35

Cou

nts

Binding Energy [eV]

NH2

NHCO


Ag

Ag

Ag

Ag

Ag

FA FA FA

PRIMARY ANTIBODY PRIMARY ANTIBODY (FOLATE 8/33)(FOLATE 8/33)

SECONDARY ANTIBODY (SECONDARY ANTIBODY (Rabbit Rabbit polyclonal to Mouse IgG polyclonal to Mouse IgG (HRP) (HRP) ))

ELISA TEST (*)

(*) Eastern Piedmont University A. AvogadroREACTION WITH REACTION WITH

CROMOGENEOUS COMPOUND CROMOGENEOUS COMPOUND AND UV-MEASUREMENT OF AND UV-MEASUREMENT OF

ABSORBANCEABSORBANCE


Folic acid grafted Ag-Folic acid grafted Ag-nanoclusters-silica thin nanoclusters-silica thin

films are able to films are able to selectively bind the selectively bind the

proper antibodyproper antibody

CONCLUSIONS …CONCLUSIONS …

Silver nanoclusters-silica composite films Silver nanoclusters-silica composite films have been effectively silanized with 3-have been effectively silanized with 3-aminopropyltriethoxysilaneaminopropyltriethoxysilane

Folic acid has been successfully grafted to Folic acid has been successfully grafted to silanized films via carbodiimide activationsilanized films via carbodiimide activation

The characteristic SPR absorption is The characteristic SPR absorption is maintained after functionalizationmaintained after functionalization

FA-functionalized films are able to selectively FA-functionalized films are able to selectively recognize the proper antibodyrecognize the proper antibody

… … AND FUTURE DEVELOPMENTSAND FUTURE DEVELOPMENTS

SPR absorption measurement in presence of SPR absorption measurement in presence of the antibody will be performed in humid the antibody will be performed in humid environment in order to evaluate the shift due environment in order to evaluate the shift due to selective bindingto selective binding

Recognition experiment with marked healthy Recognition experiment with marked healthy and cancerous cells will be performed and cancerous cells will be performed

ThankThanks!s!

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FOLIC ACID GRAFTING TO Ag NANOCLUSTERS-SILICA THIN FILMS