vi
Preface
Spin-coated thin films of PNHSMA were investigated in Chap. 4 as reactive
layers for obtaining platforms for biomolecule immobilization with high molecular
loading. The surface reactivity of PNHSMA films in coupling reactions with aminofunctionalized poly(ethylene glycol) (M n : 500 g/mol) (PEG 500 -NH 2 ) was determined by FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), fluorescence
microscopy, and ellipsometry measurements. The PEG 500 -NH 2 loading observed was
about three times higher for the polymer thin films compared to SAMs of 11,11
-
dithiobis(N-hydroxysuccinimidyl undecanoate) (NHS-C10) on Au. These data indicate that the coupling reactions are not limited to the outermost surface layer of the
polymer films, but proceed into the surface-near regions of the films. An increased
loading was also observed by surface plasmon resonance (SPR) measurements for the
covalent immobilization of amino-functionalized probe DNA. Hybridization of fluorescently labeled target DNA was successfully detected by fluorescence microscopy
and surface plasmon resonance-enhanced fluorescence spectroscopy (SPFS), thereby
demonstrating that thin films of PNHSMA show robustness and comprise an attractive and simple platform for the immobilization of biomolecules with high molecular densities. Finally, successful application of PNHSMA films as platform for
biosensors for pathogen detection was demonstrated using a protein G-mediated
antibody-based detection of listeria.
The investigation of PS 690 -b-PtBA 1210 films and their derivatization to obtain
tailored biointerfaces was presented in Chap. 5. Derivatized PS 690 -b-PtBA 1210 films
showed good stability under a broad range of conditions. Hydrolysis of the reactive tbutyl ester groups was performed in trifluoroacetic acid, 3M aqueous HCl, and in the
gas phase (HCl). After the subsequent activation with NHS ester groups a variety of
amino-functionalized (bio)molecules were covalently immobilized on the previously
hydrolyzed surfaces. The reactivity of the PS 690 -b-PtBA 1210 films and in particular the
controllable loading with amino functionalized PEG 500 -NH 2 were studied by FTIR
and XPS. Subsequently, the immobilization of biologically relevant molecules, such
as bovine serum albumin (BSA) and poly(L)lysine (PLL), on PS 690 -b-PtBA 1210 films
were studied by fluorescence microscopy. To demonstrate possible applications of
the PS 690 -b-PtBA 1210 -based platform as viable biointerfaces, hybridization of target
DNA with previously covalently immobilized probe DNA, as well as the interaction
of two different types of cells, i.e., K562 and pancreatic cancer cells, on functionalized
PS 690 -b-PtBA 1210 films were investigated.
In Chap. 6, the fabrication of robust biomolecule microarrays on spin-coated thin
films of PNHSMA on oxidized silicon and glass by reactive µCP was described.
The approach combines the advantages of activated polymer thin films as coupling
layers, characterized by high reactivity and high molecular loading (Chaps. 3 and 4),
with the versatility and flexibility of soft lithography. The transfer of amino end functionalized PEG 500 -NH 2 from oxidized poly(dimethyl siloxane) (PDMS) elastomer
stamps to PNHSMA films was shown by FTIR spectroscopy, XPS, fluorescence
microscopy, and ellipsometry measurements which result in covalent coupling and
identical grafting densities as reported in Chap. 4 for coupling from solution. The
PEG-protected areas effectively inhibited the adsorption of fluoresceinamine, BSA,
as well as 25-mer DNA, while the unreacted NHS ester groups retained their reactivity
Preface
Spin-coated thin films of PNHSMA were investigated in Chap. 4 as reactive
layers for obtaining platforms for biomolecule immobilization with high molecular
loading. The surface reactivity of PNHSMA films in coupling reactions with aminofunctionalized poly(ethylene glycol) (M n : 500 g/mol) (PEG 500 -NH 2 ) was determined by FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), fluorescence
microscopy, and ellipsometry measurements. The PEG 500 -NH 2 loading observed was
about three times higher for the polymer thin films compared to SAMs of 11,11
-
dithiobis(N-hydroxysuccinimidyl undecanoate) (NHS-C10) on Au. These data indicate that the coupling reactions are not limited to the outermost surface layer of the
polymer films, but proceed into the surface-near regions of the films. An increased
loading was also observed by surface plasmon resonance (SPR) measurements for the
covalent immobilization of amino-functionalized probe DNA. Hybridization of fluorescently labeled target DNA was successfully detected by fluorescence microscopy
and surface plasmon resonance-enhanced fluorescence spectroscopy (SPFS), thereby
demonstrating that thin films of PNHSMA show robustness and comprise an attractive and simple platform for the immobilization of biomolecules with high molecular densities. Finally, successful application of PNHSMA films as platform for
biosensors for pathogen detection was demonstrated using a protein G-mediated
antibody-based detection of listeria.
The investigation of PS 690 -b-PtBA 1210 films and their derivatization to obtain
tailored biointerfaces was presented in Chap. 5. Derivatized PS 690 -b-PtBA 1210 films
showed good stability under a broad range of conditions. Hydrolysis of the reactive tbutyl ester groups was performed in trifluoroacetic acid, 3M aqueous HCl, and in the
gas phase (HCl). After the subsequent activation with NHS ester groups a variety of
amino-functionalized (bio)molecules were covalently immobilized on the previously
hydrolyzed surfaces. The reactivity of the PS 690 -b-PtBA 1210 films and in particular the
controllable loading with amino functionalized PEG 500 -NH 2 were studied by FTIR
and XPS. Subsequently, the immobilization of biologically relevant molecules, such
as bovine serum albumin (BSA) and poly(L)lysine (PLL), on PS 690 -b-PtBA 1210 films
were studied by fluorescence microscopy. To demonstrate possible applications of
the PS 690 -b-PtBA 1210 -based platform as viable biointerfaces, hybridization of target
DNA with previously covalently immobilized probe DNA, as well as the interaction
of two different types of cells, i.e., K562 and pancreatic cancer cells, on functionalized
PS 690 -b-PtBA 1210 films were investigated.
In Chap. 6, the fabrication of robust biomolecule microarrays on spin-coated thin
films of PNHSMA on oxidized silicon and glass by reactive µCP was described.
The approach combines the advantages of activated polymer thin films as coupling
layers, characterized by high reactivity and high molecular loading (Chaps. 3 and 4),
with the versatility and flexibility of soft lithography. The transfer of amino end functionalized PEG 500 -NH 2 from oxidized poly(dimethyl siloxane) (PDMS) elastomer
stamps to PNHSMA films was shown by FTIR spectroscopy, XPS, fluorescence
microscopy, and ellipsometry measurements which result in covalent coupling and
identical grafting densities as reported in Chap. 4 for coupling from solution. The
PEG-protected areas effectively inhibited the adsorption of fluoresceinamine, BSA,
as well as 25-mer DNA, while the unreacted NHS ester groups retained their reactivity