Biofunctional hybrid materials: bimolecular organosilane monolayers on FeCr alloys

Abstract

Hybrid organic-inorganic interfaces are the key to functionalization of stainless steel (SS). We present a solution-based deposition method for fabricating uniform bimolecular organosilane monolayers on SS and show that their properties and functionalities can be further developed through site-specific biotinylation. We correlate molecular properties of the interface with its reactivity via surface sensitive synchrotron radiation mediated high-resolution photoelectron spectroscopy (HR-PES) and chemical derivatization (CD), and we demonstrate specific bonding of streptavidin proteins to the hybrid interface. The method facilitates efficient growth of uniform bimolecular organosilane monolayers on SS under ambient conditions without the need to prime the SS surface with vacuum-deposited inorganic buffer layers. The obtained insights into molecular bonding, orientation, and behaviour of surface-confined organofunctional silanes on SS enable a new generic approach to functionalization of SS surfaces with versatile nanomolecular organosilane layers.

Non‐stick properties of thin‐film coatings on dental‐restorative instruments

“…; and (ii) it sets surface chemistry to a state known as being suitable for SAM deposition. The bonding of the self‐assembled organosilicon molecules is improved, as ALD TiO 2 has more available hydroxyl groups for the adsorption of silanes . As the self‐saturating surface reactions of ALD allow conformal and uniform deposition on three‐dimensional morphologies , the chemical bonding can be expected to be solely between ALD and SAM organosilicon.…”

“…Compared with many other structuring methods for superhydrophobicity found in the literature, wet etching is inexpensive, simple, and easily adapted to different materials. The ALD layer repassivates the stainless‐steel surface, and allows stronger and more durable bonding of SAMs; when compared with stainless steel, it has a larger number of available hydroxyl groups for the adsorption of silanes . Self‐assembled monolayers of fluorinated organosilicon allow phobicity towards non‐polar liquids without affecting the submicron scale dimensions of the etched surface.…”

Improved antifouling properties and selective biofunctionalization of stainless steel by employing heterobifunctional silane-polyethylene glycol overlayers and avidin-biotin technology

“…However, for optimal biological performance biofunctionality is also required. For instance, enzymes, such as lysozyme and alkaline phosphatase have been used to introduce antibacterial properties or other specific biological functions to surfaces 11 12 .…”

“…Silanes are well known and widely used surface-functionalization agents that are able to bind to the hydroxide groups of the SS oxide layer, and in suitable conditions strictly organized monolayers can be formed 12 13 . For example, Slaney et al .…”

“… 13 have used atomic layer deposition (ALD) to precoat SS surfaces to facilitate the subsequent addition of bimolecular silane layers. In addition, Si-O-Si siloxane bonds can be formed between adjacent silane molecules, which adds to the tenacity of the overlayer 12 14 15 . Various types of functionalized silanes, such as the heterobifunctional silane-polyethylene glycol (silane-PEG) used in this study, are also readily commercially available and in general they are relatively inexpensive and considered environmentally safe.…”