) ranging from 14 to 100W.
was adjusted by the modulation of the “off-time” (0-3.6 ms) while the plasma “on-time” and the peak power were kept constant at 0.5 ms and 100W, respectively. It should be noted that at this power value, the discharge is inductively coupled.1,27 XPS. XPS measurements on the as-deposited and derivatized Pr-PPF/MPTS-SAM were performed using a PHI 5000 VersaProbe apparatus with an Al Kα monochromatized radiation source (1486 eV). The XPS instrument is directly connected to the plasma deposition chamber. Hence, in the case of the as-deposited Pr-PPF, the samples were analysed without exposure to the air. The pressure in the analysis chamber was typically 3.10-7 Pa. Photoelectrons were collected at a take-off angle of 45° from the surface normal. All spectra were charge corrected with respect to the hydrocarbon component of the C 1s peak at 285 eV. The XPS survey were acquired using a pass energy of 117.4eV. Concerning the high resolution peaks of each element, a pass energy of 23.5 eV was employed. For spectral curve fitting of the carbon photoelectron peak using PHI Multipak Software, a full width at halfmaximum of 1-1.3 eV and a Gauss-Lorentz function (70-85% Gauss) were applied. The high resolution C1s photoelectrons peaks were acquired with energy step of 0.2 eV and 0.05 eV for
6 ACS Paragon Plus Environment
Page 7 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
the Pr-PPF and the MPTS-SAM, respectively. The XPS resolution of our apparatus is estimated to be 0.5 eV.28 ToF-SIMS. Static ToF-SIMS measurements were acquired using a ToF-SIMS IV instrument from ION TOF GmbH. A 25 keV Ga+ ion beam at a current of 0.8 pA rasterred over a scan area of 200*200 µm2 during 150 sec. Owing to the tendency for sulfur, oxygen and nitrogen to form negative ions under primary ions bombardment during ToF-SIMS experiments, the measurements were acquired in negative mode.29 In the spectra, the peak intensity of the secondary ions was normalized with respect to the total ion count. Ellipsometry. Spectroscopic ellipsometry data in the visible range was obtained using a UVISEL by Jobin Yvon Horiba Spectroscopic Ellipsometer equipped with a DeltaPsi 2 data analysis software. The system acquired a spectrum ranging from 2 to 4.5 eV (corresponding to 300-750 nm) with 0.05 eV (or 7.5 nm) intervals. To assess the thickness of the as-deposited and the derivatized MPTS-SAM, a 3-layer model was used: Si/SiO2 (Native oxide) /SAM. The optical properties of Si and SiO2 are found in the software library and integrated to the model. The SiO2 thickness was measured independently and estimated to 12 Å. Concerning the SAM, a refractive index of 1.5 was used. More details about the methodology can be found elsewhere.25 The accuracy of the SAM thickness measurements is estimated to be ±2 Å. Derivatization reaction. The derivatization reactions were carried out in a phosphate buffer (KH2PO4/Na2HPO4, Chem Lab) at pH = 7 for kinetic considerations and stability of Nethylmaleimide (99%, Sigma Aldrich) in aqueous solution.20,22 The N-ethylmaleimide concentration was fixed at10-1 M. The reaction duration varied from 3h to 200h for Pr-PPF and was fixed to 18h in the case of MPTS-SAM. After immersion, the Pr-PFF/MPTS-SAM were rinsed in the buffer solution (without N-ethylmaleimide) for 5 min to eliminate the unreacted molecules and dried under nitrogen flow before analysis.
7 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 8 of 24
Results and discussion In order to evaluate the efficiency of the grafting of MPTS-SAM on silicon substrate, thickness measurements using ellipsometry are performed. Table 1 summarizes the thicknesses of the SAMs and provides a comparison with the expected value for a “nearperfect” densely packed SAM. The expected thickness corresponds to the length of the molecules, as given by PM3 conformation optimization with the CS-MOPAC software30 assuming that the main axis of the molecule is perpendicular to the surface substrate. A good agreement between the measured and the expected values is observed suggesting that alkyl chains are densely packed and that end groups are directed away from the silicon surface. After the chemical derivatization (CD) reaction, an increase in the thickness is observed (from 6.7Å to 12Å, See table1). The obtained thickness is consistent with the expected theoretical value considering the grafting of N-ethylmaleimide molecule at the –SH terminal group through the reaction described in the Equation 1 (see Figure S1 for a schematic description). Table 1. Thickness of the as-deposited MPTS-SAM and after the derivatization reaction. Thickness ( Å ) Theoretical Measured MPTS-SAM 7.2 6.7 ± 2 MPTS-SAM after CD 11.8 12 ± 2 Monolayer
To assess the variation of the chemical composition of the surface after CD, the XPS survey measured before and after CD are compared (Figure 1). Concerning the as-deposited MPTS-SAM, the data reveal the presence of sulfur and carbon illustrating again the grafting efficiency (Figure 1a). After the CD procedure, nitrogen, present in the labeling molecule, is clearly identified in the survey (Figure 1b). Following the reaction described in Equation 1, new carbon-based functionalities are introduced. Therefore, the high resolution C1s peaks were compared before and after the mentioned reaction in order to get information on the chemical reactions occurring during immersion (Figure 2). All components used in this work
8 ACS Paragon Plus Environment
Page 9 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
for the spectral curve fitting are summarized in Table 2. According to the chemical composition of the as-deposited MPTS-SAM, three components are used for the fitting procedure: C1, C2 and C3 associated to C-Si, C-S, C-C/C-H, respectively (Figure 2a). After CD , two additional components, namely C4 (C-N) and C5 (O=C-N) are identified (Figure 2b). Both these functionalities are present in the N-ethylmaleimide structure and therefore likely result from the incorporation of the labeling molecule through the derivatization reaction described in the Equation 1. In addition, it should be mentioned that the position of the N1s signal (not shown) at 400.5 eV is consistent with the expected value of a nitrogen atom involved in a maleimide structure.31
Figure 1: XPS survey of the (a) as-deposited MPTS-SAM and (b) after the derivatization reaction.
9 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 10 of 24
Figure 2: C1s photoelectron peak fitting corresponding to (a) a as-deposited MPTS-SAM and (b) after the derivatization reaction. Table 2. Labeling of all components used in this work for the spectral curve fitting of the C1s photoelectron peak shown in Figures 2 and 5.
Components
C1 C2 C3
Attribution MPTS-SAM MPTS-SAM Pr-PPF (After CD) C-Si C-Si (284.6 eV) (284.4eV) / C-C/C-H (285 eV) C-S (285.6 eV)
C4
/
C5
/
C-C/C-H (284.9 eV) C-S (285.6 eV) C-N (286.5 eV) O=C-N (288. 6 eV)
C-C/C-H (284.8 eV) C-S (285.6 eV)
/ /
Pr-PPF (After CD)
References
/
32
C-C/C-H (284.8 eV) C-S (285.6 eV) C-O/C-N (286.4 eV) O=C-N (288. 5 eV)
31
31
33,34
31,34
10 ACS Paragon Plus Environment
Page 11 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
As a complement to the XPS data, ToF-SIMS analysis have been performed on the same samples (Figure 3). After CD, a new peak at m/z = 158 is clearly observed in the mass spectra (Figure 3b). Based on the CD mechanism (Equation 1), this negative ion could be assigned to the [C6H8NO2S]- fragment (exact m/z = 158.028, observed m/z = 158.021). The assumed fragmentation pathway leading to the emission of this fragment is schematically represented in Figure 4a. The detection of this anion, characteristic of the probe molecule, constitutes an additional evidence of a reaction between the –SH groups of the MPTS-SAM and N-ethylmaleimide. In order to get more quantitative information, the yield of the derivatization reaction on MPTS-SAM is calculated considering the nitrogen to sulfur ratio (N/S) measured by XPS. Although the CD reaction is considered as nearly quantitative in the literature, a value of 0.48 was found meaning that only ~50% of –SH functionalities have reacted with the labeling molecule. This result can be explained taking into account some steric effects considering the space between two neighboring chains in MPTS-SAM and the size of the labeling molecule. Indeed, the area per molecule in a MPTS-SAM is estimated to 23 Å2 giving a space between chains of 5.4 Å.24 On the other hand, based on MOPAC calculation data (See Figure S1), the diameter of the labeling molecule can be estimated to 6.3 Å. If we assimilate the molecules to cylinder, the space between two chains in MPTS-SAM is too low to allow a reaction with two neighboring –SH functions (See a schematic diagram in Figure S2). Considering this steric effect, only one –SH group over two can react with the labeling molecule which is consistent with our experimental data. Therefore, the derivatization reaction can be considered as nearly quantitative. The MPTS-SAM situation is obviously quite different than the one encountered in PPF for which the density of –SH groups is likely dramatically lower. Based on our theoretical estimation,
a minimal distance of ~ 6Å is required for the reaction occurring at two
11 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 12 of 24
neighboring –SH groups. Considering simple carbon-carbon bond (~1.54Å), this minimal space corresponds to a density of –SH group of around 40%. The latter value corresponds therefore to the maximum –SH density which can be reached using our method. Nevertheless, it is accepted that for plasma polymers the density of a particular chemical group is most of the time much lower than 40% due to the high number of fragmentations/rearrangements reactions occurring in the plasma and at the growing film interface.8,16,35 Therefore, for this class of materials, the steric effect induced by the derivatization molecule would not represent a limiting factor for a quantitative determination of the –SH density.
Figure 3: Partial normalized negative ToF-SIMS spectra of a (a) as-deposited MPTS-SAM and (b) after the derivatization reaction.
Figure 4: Possible fragmentation pathways providing secondary ions at (a) m/z = 158 ([C6H8NO2S]-) and (b) at m/z = 142 ([C6H8NO3]- ) observed in the ToF-SIMS spectra.
12 ACS Paragon Plus Environment
Page 13 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
Concerning the Pr-PPF, for all deposition conditions, the XPS survey spectra (not shown) reveal the presence of nitrogen after the chemical derivatization (CD) procedure whatever the reaction duration while, obviously, it is absent from the as-deposited Pr-PPF XPS spectrum. The elemental composition of the Pr-PPF synthesized at different
at each fabrication step is summarized in the Table S1 (Supporting Information). In order to get more information about the reactions occurring during CD, the high resolution C1s envelope was examined before and after derivatization (Figure 5). Figure 5a, corresponding to the asdeposited Pr-PPF, is composed of two components (C2 and C3) referring to aliphatic bonds and carbon/sulfur bond (C-SR, C-SH,C=S), respectively (See Table 2 for component labeling).31 Figure 5b shows that after CD similarly to the derivatized MPTS-SAM, new chemical functionalities are introduced in the Pr-PFF as revealed by the appearance of two additional components: C4 and C5 associated to C-NR/C-OR and O=C-N bonds, respectively (see Table 2). The presence of the O=C-N and C-N bonds is attributed to the incorporation of Nethylmaleimide at the Pr-PPF surface most likely by following the reaction depicted in Equation 1. Concerning the C4 component, it should be noted that in addition to C-N bonds, a contribution of C-OR has also to be taken into account. Indeed, the presence of C-OR bonds after CD results from the reaction between the trapped Pr-PFF radicals and the ambient oxygen or water present in the CD solution as frequently encountered in plasma polymerization.36
13 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 14 of 24
Figure 5: C1s photoelectron peak fitting corresponding to the analysis of a Pr-PPF synthesized at
= 100W (a) as-deposited and (b) after the derivatization reaction during 86h.
In addition, ToF-SIMS analyses were performed on the same samples (Figure 6). After CD, a new peak at m/z = 158 as previously observed in derivatized MPTS-SAM and attributed to [C6H8NO2S]- fragment (exact m/z = 158.028, observed m/z = 158.018) is clearly observed in the mass spectra (Figure 6b). This additionally confirms the grafting of Nethylmaleimide in Pr-PPF. In a lesser extent, another signal at m/z = 142 is also identified (Figure 6b). The latter is assigned to [C6H8NO3]- (exact m/z = 142.055, observed m/z = 142.046) fragment for which a probable structure is represented in Figure 4b. This ion likely results from a reaction between –OH functionalities incorporated in the Pr-PFF by postoxidation reaction and N-ethylmaleimide. Based on organic chemistry literature, this reaction is unexpected since it should be catalyzed under basic or acidic conditions to occur efficiently.37 Nevertheless, in their work, Jin et al. compared the reactivity of -OH/-SH 14 ACS Paragon Plus Environment
Page 15 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
terminated oligonucleotides towards maleimide moieties supported on a surface and showed that a potential reaction between –OH and maleimide species is possible.38 Based on comparative fluorescence spectroscopy measurements, the reaction yield between –OH functions and the maleimide surface is estimated to be approximately 10% if we consider a complete reaction with –SH groups. In a first approach, this side reaction can therefore be neglected as proved by Shen et al. through XPS measurements.22 In our case, although only ~4 at.% of oxygen is introduced through post-oxidation of the Pr-PPF, this fragment is likely observed because of the extreme sensitivity of ToF-SIMS for the detection of oxygen-based anions.29
Figure 6: Partial normalized negative ToF-SIMS spectra of a Pr-PFF synthesized for
= 100 W (a) as-deposited and (b) after the derivatization reaction during 86h. In order to complete our understanding, the kinetics of the N-ethylmaleimide CD of the Pr-PPF has been evaluated. Figure 7 reports the –SH density as a function of the reaction 15 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 16 of 24
duration for Pr-PPF synthesized for
= 14W, 38W and 100W. Assuming a selective reaction between N-ethylmaleimide and the –SH functions, the concentration of carbon bearing the –SH groups [SH] is calculated using Equation 2.16 [SH] =
[N] . 100 [C] − 6[N]
(%)
Equation 2
Where [N] and [C] represent the atomic carbon and nitrogen concentration measured by XPS, respectively. The term 6[N] is related to the amount of carbon introduced through the CD reaction (See Equation 1). Independently of
, [SH] increases strongly with the reaction duration and then, reaches a plateau suggesting that all the –SH functions have reacted with N-ethylmaleimide within the analysis depth of the XPS, which is estimated to be 7 nm.39 This trend is explained by a fast surface reaction 2 followed by a diffusion limited reaction in the bulk of the Pr-PPF. In our range of
, it can be learned that, for all power conditions, the plateau appears for similar reaction duration (~40h). This suggests that the diffusion of the N-ethylmaleimide molecule, often linked to the plasma polymer crosslinking, is not affected by
. In addition, [SH] measured in the plateau region is similar whatever the
. This is also supported by ToF-SIMS data related to the relative intensity of the [C6H8NO2S]- fragment (See Figure S3
in Supporting Information ). These observations consistently suggest that, in our range of power, the plasma polymerization process is not significantly affected by
. Indeed, in plasma polymerization, it is generally accepted that the retention of the functionality hosted by the precursor molecule (-SH function in our case) and the crosslinking of the plasma polymer evolve with inversely proportional trends as a function of
.26 However, in a recent work of Hegemann et al, it has been showed that the retention of a particular function as well as the cross-linking degree of the layers strongly depend on the “momentum flux” per deposition rate to the growing film interface.40 This latter parameter is directly proportional to the energy and the flow of bombarding ions. In our case, it can be reasonably assumed that the
16 ACS Paragon Plus Environment
Page 17 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
growth of the layer occurs mainly during ton as our precursor does not contain any unsaturation (double, triple bond) limiting therefore its grafting at the interface during toff. Therefore, the energetic conditions trough ionic bombardment to the growing film should be equivalent for all
as ton and the peak power were fixed. Based on these considerations, we expect an equivalent momentum flux per deposition rate and consequently a nearly constant [SH] and cross-linking degree with
explaining the data recorded in Figure 7. Hence, considering the modulation of
only through the variation of toff, the peak power seems to be the major factor controlling the layer properties in case of –SH-based plasma polymer films. It should be mentioned that the [SH] density measured in this work (varying from 3.5 to 5% taking into account the error bar) are in good agreement with data reported for other types of PPF for similar conditions.6,16
17 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 18 of 24
Figure 7: Evolution of the [SH] (calculated using equation 2) as a function of the reaction duration for
= 100W (a), 38 W (b) and 14 W (c). The errors bars correspond to the standard deviations values calculated from measurements using different areas on the sample’s surface. The line is drawn as a visual guide.
Conclusions A chemical derivatization method has been established to quantitatively probe the –SH function in propanethiol plasma polymers using N-ethylmaleimide as a labeling molecule. The derivatization reaction was first evaluated on a “model” surface, namely 3mercaptopropyl-trimethoxysilane self-assembled monolayers exhibiting a –SH terminated function. The combination of ellipsometry, XPS and ToF-SIMS data clearly demonstrate the grafting of N-ethylmaleimide through a chemical reaction with –SH group. Considering the
18 ACS Paragon Plus Environment
Page 19 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
steric effect induced by the grafting of N-ethylmaleimide, it was shown that the derivatization reaction is quantitative. Concerning the propanethiol plasma polymers, it has been shown that the reaction between the –SH function and N-ethylmaleimide is not fully selective and that the –OH function can also react with the derivative agent but to a significantly lower extent than the – SH groups. The study of the kinetics of the reaction reveal first a fast surface reaction followed by a diffusion limited step. We believe that these results pave the way for optimizing the surface concentration of – SH groups in sulfur-based plasma polymers.
Acknowledgements
The authors thank F.R.I.A grant of the Communauté de Française de Belgique and the Belgian Government through the «Pôle d’Attraction Interuniversitaire» (PAI, P7/34, “PlasmaSurface Interaction”, Ψ) for financial support.
Supporting Information Schematic description of MPTS-SAM exhibiting a N-ethylmaleimide grafted at the sulfur extremity. Comparison of the thiol density measured by XPS and ToF-SIMS. Elemental composition measured by XPS for Pr-PPF as deposited and after the chemical derivatization reaction. This material is available free of charge via the Internet http://pubs.acs.org.
19 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 20 of 24
References (1) Thiry, D.; Britun, N.; Konstantinidis, S.; Dauchot, J.-P.; Denis, L.; Snyders, R. Altering the sulfur content in the propanethiol plasma polymers using the capacitive-to-inductive mode transition in inductively coupled plasma discharge. Appl. Phys. Lett. 2012, 100, 071604. (2) Smith, E. A.; Wanat, M. J.; Cheng, Y.; Barreira, S. V. P.; Frutos, A. G.; Corn, R. M. Formation, Spectroscopic Characterization, and Application of Sulfhydryl-Terminated Alkanethiol Monolayers for the Chemical Attachment of DNA onto Gold Surfaces. Langmuir 2001, 17, 2502-2507. (3) Schofield, W. C. E.; McGettrick, J.; Bradley, T. J.; Badyal, J. P. S.; Przyborski, S. Rewritable DNA Microarrays. J. Am. Chem. Soc. 2006, 128, 2280-2285. (4) Ali, M. B.; Bessueille, F.; Chovelon, J. M.; Abdelghani, A.; Jaffrezic-Renault, N.; Maaref, M. A.; Martelet, C. Use of ultra-thin organic silane films for the improvement of gold adhesion to the silicon dioxide wafers for (bio)sensor applications. Mater. Sci. Eng., C 2008, 28, 628-632. (5) Švorčík, V.; Chaloupka, A.; Záruba, K.; Král, V.; Bláhová, O.; Macková, A.; Hnatowicz, V. Deposition of gold nano-particles and nano-layers on polyethylene modified by plasma discharge and chemical treatment. Nucl. Instrum. Methods Phys. Res., Sect. B 2009, 267, 2484-2488. (6) Denis, L.; Cossement, D.; Godfroid, T.; Renaux, F.; Bittencourt, C.; Snyders, R.; Hecq, M. Synthesis of Allylamine Plasma Polymer Films: Correlation between Plasma Diagnostic and Film Characteristics. Plasma Process. Polym. 2009, 6, 199-208. (7) Friedrich, J. Mechanisms of Plasma Polymerization – Reviewed from a Chemical Point of View. Plasma Process. Polym. 2011, 8, 783-802. (8) Voronin, S. A.; Zelzer, M.; Fotea, C.; Alexander, M. R.; Bradley, J. W. Pulsed and Continuous Wave Acrylic Acid Radio Frequency Plasma Deposits: Plasma and Surface Chemistry. J. Phys. Chem. B 2007, 111, 3419-3429. (9) Kim, J.; Shon, H. K.; Jung, D.; Moon, D. W.; Han, S. Y.; Lee, T. G. Quantitative Chemical Derivatization Technique in Time-of-Flight Secondary Ion Mass Spectrometry for Surface Amine Groups on Plasma-Polymerized Ethylenediamine Film. Anal. Chem. 2005, 77, 4137-4141. (10) Snyders, R.; Zabeida, O.; Roberges, C.; Shingel, K. I.; Faure, M.-P.; Martinu, L.; Klemberg-Sapieha, J. E. Mechanism of adhesion between protein-based hydrogels and plasma treated polypropylene backing. Surf. Sci. 2007, 601, 112-122. 20 ACS Paragon Plus Environment
Page 21 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
(11) Chevallier, P.; Castonguay, M.; Turgeon, S.; Dubrulle, N.; Mantovani, D.; McBreen, P. H.; Wittmann, J. C.; Laroche, G. Ammonia RF−Plasma on PTFE Surfaces: Chemical Characterization of the Species Created on the Surface by Vapor−Phase Chemical Derivatization. J. Phys. Chem. B 2001, 105, 12490-12497. (12) Kim, J.; Jung, D.; Park, Y.; Kim, Y.; Moon, D. W.; Lee, T. G. Quantitative analysis of surface amine groups on plasma-polymerized ethylenediamine films using UV–visible spectroscopy compared to chemical derivatization with FT-IR spectroscopy, XPS and TOFSIMS. Appl. Surf. Sci. 2007, 253, 4112-4118. (13) Holländer, A. Labelling techniques for the chemical analysis of polymer surfaces. Surf. Interface Anal. 2004, 36, 1023-1026. (14) Holländer, A.; Kröpke, S. Polymer Surface Treatment with SO2-Containing Plasmas. Plasma Process. Polym. 2010, 7, 390-402. (15) Siow, K. S.; Britcher, L.; Kumar, S.; Griesser, H. J. Sulfonated Surfaces by Sulfur Dioxide Plasma Surface Treatment of Plasma Polymer Films. Plasma Process. Polym. 2009, 6, 583-592. (16) Choukourov, A.; Biederman, H.; Slavinska, D.; Trchova, M.; Hollander, A. The influence of pulse parameters on film composition during pulsed plasma polymerization of diaminocyclohexane. Surf. Coat. Technol. 2003, 174–175, 863-866. (17) Rinsch, C. L.; Chen, X.; Panchalingam, V.; Eberhart, R. C.; Wang, J.-H.; Timmons, R. B. Pulsed Radio Frequency Plasma Polymerization of Allyl Alcohol: Controlled Deposition of Surface Hydroxyl Groups. Langmuir 1996, 12, 2995-3002. (18) Pounder, R. J.; Stanford, M. J.; Brooks, P.; Richards, S. P.; Dove, A. P. Metal free thiolmaleimide 'Click' reaction as a mild functionalisation strategy for degradable polymers. Chem. Commun. 2008, 5158-5160. (19) Misra, A.; Dwivedi, P. Immobilization of oligonucleotides on glass surface using an efficient heterobifunctional reagent through maleimide-thiol combination chemistry. Anal Biochem 2007, 369, 248-55. (20) Partis, M. D.; Griffiths, D. G.; Roberts, G. C.; Beechey, R. B. Cross-linking of Protein by Maleimido Alkanoyl N-Hydroxysuccinimido Esters. J. Protein Chem. 1983, 2, 263-277. (21) Houseman, B. T.; Gawalt, E. S.; Mrksich, M. Maleimide-Functionalized Self-Assembled Monolayers for the Preparation of Peptide and Carbohydrate Biochips†. Langmuir 2002, 19, 1522-1531. 21 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 22 of 24
(22) Shen, G.; Anand, M. F. G.; Levicky, R. X-ray photoelectron spectroscopy and infrared spectroscopy study of maleimide-activated supports for immobilization of oligodeoxyribonucleotides. Nucleic Acids Res. 2004, 32, 5973-5980. (23) Lowe, A. B. Thiol-ene "click" reactions and recent applications in polymer and materials synthesis. Polym. Chem. 2010, 1, 17-36. (24) Celle, C.; Suspène, C.; Simonato, J.-P.; Lenfant, S.; Ternisien, M.; Vuillaume, D. Selfassembled monolayers for electrode fabrication and efficient threshold voltage control of organic transistors with amorphous semiconductor layer. Org. Electron. 2009, 10, 119-126. (25) Guerin, D.; Merckling, C.; Lenfant, S.; Wallart, X.; Pleutin, S.; Vuillaume, D. Silicon−Molecules−Metal Junctions by Transfer Printing: Chemical Synthesis and Electrical Properties. J. Phys. Chem. C 2007, 111, 7947-7956. (26) Denis, L.; Thiry, D.; Cossement, D.; Gerbaux, P.; Brusciotti, F.; Van De Keere, I.; Goossens, V.; Terryn, H.; Hecq, M.; Snyders, R. Towards the understanding of plasma polymer film behaviour in ethanol: A multi-technique investigation. Prog. Org. Coat. 2011, 70, 134-141. (27) Thiry, D.; Britun, N.; Konstantinidis, S.; Dauchot, J.-P.; Guillaume, M.; Cornil, J.; Snyders, R. Experimental and Theoretical Study of the Effect of the Inductive-to-Capacitive Transition in Propanethiol Plasma Polymer Chemistry. J. Phys. Chem. C 2013, 117, 98439851. (28) Ligot, S.; Renaux, F.; Denis, L.; Cossement, D.; Nuns, N.; Dubois, P.; Snyders, R. Experimental Study of the Plasma Polymerization of Ethyl Lactate. Plasma Process. Polym. 2013, 10.1002/ppap.201300025. (29) Benninghoven, A.; Rudenauer, F. G.; Werner, H. W. Secondary Ion Mass Spectrometry: Basic Concepts, Instrumental Aspects, Applications and Trends; John Wiley & Sons, 1987; p 218-238. (30) ChemOffice software by CambridgeSoft Corporation, Cambridge, U.K, 2005 (31) Beamson, G.; Briggs, D. High Resolution XPS of Organic Polymers: The Scienta ESCA300 Database; John Wiley & Sons, 1992. (32) O'Hare, L.-A.; Hynes, A.; Alexander, M. R. A methodology for curve-fitting of the XPS Si 2p core level from thin siloxane coatings. Surf. Interface Anal. 2007, 39, 926-936.
22 ACS Paragon Plus Environment
Page 23 of 24
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Langmuir
(33) Xiao, S.-J.; Brunner, S.; Wieland, M. Reactions of Surface Amines with Heterobifunctional Cross-Linkers Bearing Both Succinimidyl Ester and Maleimide for Grafting Biomolecules. J. Phys. Chem. B 2004, 108, 16508-16517. (34) Sun, G.; Hovestädt, M.; Zhang, X.; Hinrichs, K.; Rosu, D. M.; Lauermann, I.; Zielke, C.; Vollmer, A.; Löchel, H.; Ay, B.; Holzhütter, H.-G.; Schade, U.; Esser, N.; Volkmer, R.; Rappich, J. Infrared spectroscopic ellipsometry (IRSE) and X-ray photoelectron spectroscopy (XPS) monitoring the preparation of maleimide-functionalized surfaces: from Au towards Si (111). Surf. Interface Anal. 2011, 43, 1203-1210. (35) Denis, L.; Marsal, P.; Olivier, Y.; Godfroid, T.; Lazzaroni, R.; Hecq, M.; Cornil, J.; Snyders, R. Deposition of Functional Organic Thin Films by Pulsed Plasma Polymerization: A Joint Theoretical and Experimental Study. Plasma Process. Polym. 2010, 7, 172-181. (36) Gengenbach, T. R.; Griesser, H. J. Aging of 1,3-diaminopropane plasma-deposited polymer films: Mechanisms and reaction pathways. J. Polym. Sci., Part A: Polym. Chem. 1999, 37, 2191-2206. (37) Clayden, J.; Greeves, N.; Warren, S.; Wothers, P.; Pousse, A. Chimie organique; De Boeck Supérieur, 2002; p 233-234. (38) Jin, L.; Horgan, A.; Levicky, R. Preparation of End-Tethered DNA Monolayers on Siliceous Surfaces Using Heterobifunctional Cross-Linkers. Langmuir 2003, 19, 6968-6975. (39) This value was calculated using QUASES-IMFP-TPP2M software taking into account the kinetic energy of the C1s photoelectron peak (1201 eV), a polymer density of 0.9 g/ml and a take-off angle of 45° from normal to the surface for electrons collection. (40) Hegemann, D.; Körner, E.; Blanchard, N.; Drabik, M.; Guimond, S. Densification of functional plasma polymers by momentum transfer during film growth. Appl. Phys. Lett. 2012, 101, 211603.
23 ACS Paragon Plus Environment
Langmuir
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Page 24 of 24
Table of Contents Graphic
24 ACS Paragon Plus Environment
