Preparation And Application Of Reconfigurable Surface Based On Disulfur-diselenium Dynamic Photochemistry

The precise regulation of surface groups and functional molecules plays an important role in various fields such as electronic devices,optical devices,biomaterials,and biosensing materials.Over the past few decades,researchers have developed many surface modification strategies based on different chemical reactions.However,most of surfaces can only achieve one single performance or dynamic conversion of two properties,which limits the practical application of the material.Reconfigurable surfaces can realize multi-state switching of multifunctional surfaces,endowing material surfaces with the ability to adapt to rapidly changing environments or different applications,which has potential application value for building highly flexible smart surfaces,such as sensing surfaces and biomimetic surfaces.However,there are still many challenges and few studies on the preparation of controlled and multifunctional surfaces.In this paper,we introduce the disulfide-diselenide dynamic photochemistry into the material surface,and take advantage of the reversible properties of this photochemical reactions(bonding and bond-breaking reactions can occur repeatedly).Thus,the surface molecules can be easily replaced,showing excellent photodynamic reconstruction performance.On this basis,we investigated the feasibility of this reconfigurable surface for cell culture,tested the effect of different hydrophilic and hydrophobic molecules and functional biomoleculars surfaces on cells,and constructed cell array chips and multifunctional chips.The detailed works are listed as follows:(1)Preparation of UV photocontrolled reconfigurable surfaces based on disulfide bonds: we proposed a strategy for preparing intelligent surfaces based on disulfide-disulfide exchange reaction.Based on the unique photochemical reversible reactivity of disulfide bond,the disulfide bond is introduced into surface of the material,thus the surface shows reconfigurable properties,and can be quickly modified by ultraviolet light at any time as required.Due to the highly spatio-temporal controllability of light,single-component,multi-component and grayscale patterns can be created on the surface through the photomask.These patterns can be partially or completely erased or rewritten through the disulfide exchange reaction,and the modified surface exhibits excellent stability.In addition to dynamic surfaces,we also use the irreversible disulfide-ethylene reaction to endow surface with static properties,which makes it possible to create surfaces with "static and dynamic" properties,further selectively control the reversibility and irreversibility of surface properties by controlling the structure of modified molecules,and meet the demand for multifunctional properties of material surfaces in practical applications.(2)Preparation of visible light-controlled reconfigurable surfaces based on disulfide and sulfur-selenium bonds: we proposed a surface modification strategy based on disulfur-diselenium dynamic photochemistry.Visible light was used to construct patterned surfaces and the performance of the surface can be dynamically controlled by different wavelengths of light.The sulfur-selenium bond was introduced on the disulfide surface by the exchange reaction of disulfide-diselenium.Due to the difference in bond energy between disulfide bond and sulfurselenium bond,they can be excited by different wavelengths of light,so that different wavelengths of light can be used to control the chemical properties of the surface.At the same time,we have successfully extended the excitation wavelength to the visible region(405 nm),which is more suitable for the fabrication of biological interfaces.By combining with digital light processing(DLP)technology,the high-precision complex patterns of single component,multi-component and gray level on the surface are prepared,and the modified surface shows excellent stability.Compared with photomask,the patterning based on DLP technology only needs to design specific projection patterns,which greatly simplifies the modification process.In addition,the reversibility and wavelength controllability of the method significantly improve the functionality and flexibility of the surface,enabling it to achieve unique functions unavailable on conventional surfaces.(3)Application of reconfigurable surface in cell culture: the photodynamic reconfigurable performance of the surfaces can well simulate the heterogeneity and dynamicity of extracellular matrix,and has great potential in the preparation of cell scaffolds with adjustable physical and chemical properties.This paper preliminarily explored the potential application of the prepared reconfigurable surface as smart cell scaffolds in vitro.The biocompatibility of disulfide surface was evaluated.The results showed that disulfide surface showed good biocompatibility and could be used as cell scaffold materials.We further modified different hydrophilic and hydrophobic molecules and functional biomolecules on disulfide surfaces to test the effect of modified surface on cell behavior.The results showed that the disulfide surface modified by arginine-glycine-aspartic acid(RGD)sequence and polyethylene glycol(PEG)could control the pro-cell adhesion and anti-cell adhesion properties,and the hydrophilic and hydrophobic array could be constructed by surface patterning modified by hydrophilic amine groups and hydrophobic fluorine groups,which can confine the cells in the hydrophilic region.This proves that the corresponding modification of the surface through disulfide exchange reaction can well control the behavior of the cells on it,making it possible to regulate the biological activity of the cell scaffold on demand.In addition,by using this surface modification method,we modified disulfide bonds on materials such as glass slides and paper,and found that the obtained materials also showed similar reconfigurable characteristics,indicating that this method has good universality.Theoretically,it can be applied to the surfaces of various cell scaffold materials with reconfigurable properties.This provides a technical solution for preparing new,flexible and intelligent cell scaffolds in the future.