Coupling Spectroscopic Ellipsometry and Quartz Crystal Microbalance to Study Organic Films at the Solid–Liquid Interface

Richter, Ralf P.; Rodenhausen, Keith B.; Eisele, Nico B.; Schubert, Mathias

doi:10.1007/978-3-319-75895-4_17

Cited by 9 publications

(8 citation statements)

References 37 publications

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“…SE measures the change of the ellipsometric angles Ψ and Δ of polarized light upon changes in the refractive index and thicknesses of optical layers . We measured the SiO 2 layer in buffer and fitted its thickness and the angle of incidence offset based on the known optical properties of thermal SiO 2 with the J.A.…”

Section: Methodsmentioning

confidence: 99%

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Sefkow-Werner

Pennec

Machillot

et al. 2022

ACS Appl. Mater. Interfaces

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The automation of liquid-handling routines offers great potential for fast, reproducible, and labor-reduced biomaterial fabrication but also requires the development of special protocols. Competitive systems demand for a high degree in miniaturization and parallelization while maintaining flexibility regarding the experimental design. Today, there are only a few possibilities for automated fabrication of biomaterials inside multiwell plates. We have previously demonstrated that streptavidin-based biomimetic platforms can be employed to study cellular behaviors on biomimetic surfaces. So far, these self-assembled materials were made by stepwise assembly of the components using manual pipetting. In this work, we introduce for the first time a fully automated and adaptable workflow to functionalize glass-bottom multiwell plates with customized biomimetic platforms deposited in single wells using a liquid-handling robot. We then characterize the cell response using automated image acquisition and subsequent analysis. Furthermore, the molecular surface density of the biomimetic platforms was characterized in situ using fluorescence-based image correlation spectroscopy. These measurements were in agreement with standard ex situ spectroscopic ellipsometry measurements. Due to automation, we could do a proof of concept to study the effect of heparan sulfate on the bioactivity of bone morphogenetic proteins on myoblast cells, using four different bone morphogenetic proteins (BMPs) (2, 4, 6, and 7) in parallel, at five increasing concentrations. Using such an automated self-assembly of biomimetic materials, it may be envisioned to further investigate the role of a large variety of extracellular matrix (ECM) components and growth factors on cell signaling.

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Section: Methodsmentioning

confidence: 99%

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Sefkow-Werner

Pennec

Machillot

et al. 2022

ACS Appl. Mater. Interfaces

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“…The thickness changes observed in Figure with half-cycle resolution may be understood as convoluted effects on the geometrical thickness or refractive index of the SiO 2 film or its surface . Alkyl groups are highly polarizable as known by their high Raman cross sections. , Consequently, ellipsometry can sensitively detect their adsorption or removal.…”

Section: Resultsmentioning

confidence: 99%

Selectivity between SiO₂ and SiN_x during Thermal Atomic Layer Etching Using Al(CH₃)₃/HF and Spontaneous Etching Using HF and Effect of HF + NH₃ Codosing

Junige,

George

2024

Chem. Mater.

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Selectivity was examined between SiO 2 and SiN x during thermal atomic layer etching (ALE) and spontaneous etching. Thermal ALE of SiO 2 and SiN x was explored using sequential trimethylaluminum (TMA) and hydrogen fluoride (HF) with reactant exposures of 3 Torr for 45 s at 275 °C. SiO 2 thermal ALE achieved an etch per cycle (EPC) of 0.20 Å/cycle and near-ideal synergy up to 95%. SiN x thermal ALE exhibited a higher EPC of 1.06 Å/cycle. The selectivity factor was ∼5:1 for SiN x etching compared to SiO 2 etching (preferential SiN x removal) during thermal ALE using TMA and HF. Spontaneous etching was then quantified using repeated exposures of HF vapor alone at 3 Torr and 275 °C. SiO 2 spontaneous etching was minor at an etch rate of 0.03 Å/min, enabling near-ideal synergy for SiO 2 thermal ALE. In contrast, major SiN x spontaneous etching displayed an etch rate of 1.72 Å/min and predominated over SiN x thermal ALE. The selectivity factor was ∼50:1 for SiN x spontaneous etching compared to SiO 2 spontaneous etching using an HF pressure of 3 Torr. This selective SiN x spontaneous etching was attributed to F − surface species during HF exposures. NH 3 codosing with HF was then examined during thermal ALE and spontaneous etching. Thermal ALE of SiO 2 and SiN x was examined using sequential TMA and HF + NH 3 codosing with reactant exposures of 3 Torr for 45 s at 275 °C. SiO 2 thermal ALE with HF + NH 3 codosing had a high EPC of 8.83 Å/cycle. In contrast, SiN x thermal ALE with HF + NH 3 codosing was negligible. The selectivity factor was reversed and much higher at >1000:1 for SiO 2 etching compared to SiN x etching (preferential SiO 2 removal) during thermal ALE with HF + NH 3 codosing. Rapid SiO 2 spontaneous etching with HF + NH 3 codosing at 3 Torr had an etch rate of 27.50 Å/min. In contrast, SiN x spontaneous etching with HF + NH 3 codosing produced a very low etch rate of 0.02 Å/min. The selectivity factor was >1000:1 for SiO 2 spontaneous etching compared to SiN x spontaneous etching with HF + NH 3 codosing. This selective SiO 2 spontaneous etching was attributed to HF 2 − surface species during HF + NH 3 exposures. These studies revealed that the NH 3 coadsorbate during HF exposures modified the active etch species and dramatically influenced the etch selectivity between SiO 2 and SiN x . Reciprocal etch selectivity should be important for the selective removal of SiO 2 or SiN x in composite structures.

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“…Nonetheless, some density refinements considering separately the coating and media densities can be further explored, if needed. [ 29 ] Besides, the most relevant refined density expression is discussed in the ESI. Step 4 is designed as an iterative loop for validating and refining the models used.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, performing simultaneous QCM‐D/SE measurements can provide useful insights of the solid‐liquid interface. [ 29 ]…”

Section: Resultsmentioning

confidence: 99%

Establishing Quartz Crystal Microbalance with Dissipation (QCM‐D) Coupled with Spectroscopic Ellipsometry (SE) as an Advantageous Technique for the Characterization of Ultra‐Thin Film Hydrogels

Sans,

Azevedo Gonçalves,

Quintana

2024

Small

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Despite the considerable significance of utilizing ultra‐thin film (utf) hydrogels as multipurpose platforms for biomedical applications, there is still an important lack of adequate characterization techniques suitable for such materials. In this Perspective, the use of quartz crystal microbalance with dissipation (QCM‐D) coupled with spectral ellipsometry (SE) is presented as a potential tool for the complete characterization of utf‐hydrogels due to its nanometric sensitivity and high versatility. Herein, the fundaments for utf‐hydrogel characterization are settled down as far as the QCM‐D/SE response is explored under a wide range of different in operando wet working conditions measurements such as temperature or liquid media, among others. Therefore, the design of measuring protocols capable to perform is proposed and compiled, for the first time, complete and precise characterization of the cross‐link density, thickness variations (swelling ratio determination), stability analyses, and mechanical studies (including the simultaneous generation of stress‐strain curves and the evaluation of the viscoelastic; leading to the final determination of the Poisson's ratio) under different in operando conditions. Finally, the future challenges and implications for the general characterization of soft‐thin films are discussed.

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Coupling Spectroscopic Ellipsometry and Quartz Crystal Microbalance to Study Organic Films at the Solid–Liquid Interface

Cited by 9 publications

References 37 publications

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Selectivity between SiO₂ and SiN_x during Thermal Atomic Layer Etching Using Al(CH₃)₃/HF and Spontaneous Etching Using HF and Effect of HF + NH₃ Codosing

Establishing Quartz Crystal Microbalance with Dissipation (QCM‐D) Coupled with Spectroscopic Ellipsometry (SE) as an Advantageous Technique for the Characterization of Ultra‐Thin Film Hydrogels

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Coupling Spectroscopic Ellipsometry and Quartz Crystal Microbalance to Study Organic Films at the Solid–Liquid Interface

Cited by 9 publications

References 37 publications

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Automated Fabrication of Streptavidin-Based Self-assembled Materials for High-Content Analysis of Cellular Response to Growth Factors

Selectivity between SiO2 and SiNx during Thermal Atomic Layer Etching Using Al(CH3)3/HF and Spontaneous Etching Using HF and Effect of HF + NH3 Codosing

Establishing Quartz Crystal Microbalance with Dissipation (QCM‐D) Coupled with Spectroscopic Ellipsometry (SE) as an Advantageous Technique for the Characterization of Ultra‐Thin Film Hydrogels

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Selectivity between SiO₂ and SiN_x during Thermal Atomic Layer Etching Using Al(CH₃)₃/HF and Spontaneous Etching Using HF and Effect of HF + NH₃ Codosing