UV irradiation is demonstrated to initiate dopamine polymerization and deposition on different surfaces under both acidic and basic pH. The observed acceleration of the dopamine polymerization is explained by the UV‐induced formation of reactive oxygen species that trigger dopamine polymerization. The UV‐induced dopamine polymerization leads to a better control over polydopamine deposition and formation of functional polydopamine micropatterns.

Discontinuous dewetting is a powerful method enabling the generation of thousands of microdroplets with a specific geometry, volume and at predefined locations on a patterned substrate. [1][2][3][4] During the discontinuous dewetting process, liquid is moved along a surface possessing strong dewettability with a pattern of highly wettable spots to create an array of pinned droplets from picoliter up to microliter volumes. [5] The advantages of this procedure are that it is a single-step method, permits massive parallelization, is compatible with highthroughput screening (HTS) experiments [6,7] but does not depend on expensive robotics and automation, thereby minimizing experimental costs. These advantages make this method attractive for HTS of cells including single cell screenings, diagnostic or personalized medicine applications. 2Recently several biological applications requiring both miniaturization and multiplexing have been realized via discontinuous dewetting. Driven by surface tension, cell-laden hydrogels were assembled on a glass surface patterned with hydrophobic and hydrophilic regions. [8] Superhydrophobic-superhydrophilic microarrays were used to create dropletmicroarrays for high-throughput screening of living cells [7,[9][10][11] , to create arrays of hydrogel micropads [2] and for single cell screening. [12] However, most of the patterns developed thus far only apply to fabricating microdroplet arrays of high surface tension liquids such as water (surface tension γ lv =72.2 mN m -1 ), while the method often fails when most of the organic solvents with lower surface tensions (e.g., ethanol, γ lv =22.1 mN m -1 or n-hexane, γ lv =18.4 mN m -1 ) are involved.There are very few methods compatible with low surface tension liquids. Thus, Whitesides and co-workers utilized a two-phase system consisting of water and an immiscible hydrocarbon fluid to generate microdroplet arrays of hydrocarbons on patterned SAMs. [13] However, their approach is incompatible with water-miscible organic solvents. Dropletmicroarrays were also generated using discontinuous dewetting on arrays of microwells produced in poly(dimethylsiloxane) (PDMS These superomniphobic surfaces have been applied to form microdroplets of organic liquids by discontinuous dewetting. To fabricate superoleophobic surfaces, however, special designs of surface topography such as overhang [15,16] or pinecone-like structures [14] are needed, and in many cases the surfaces obtain this complex topography at the expense of their laborious preparation, sacrificing mechanical strength and transparency. [17,18] 3Here we describe a straightforward two-step approach for surface patterning that enables the fabrication of high-density arrays of microdroplets by discontinuous dewetting compatible with organic liquids with surface tension as low as γ lv =18.4 mN m -1 . The method is based on the chemical modification of a chloro(dimethyl)vinylsilane-coated flat glass surface with 1H,1H,2H,2H-perfluorodecanethiol (PFDT) via the UV-induced thiol-ene click reac...

Reactive superhydrophobic surfaces are highly promising for biotechnological, analytical, sensor, or diagnostic applications but are difficult to realize due to their chemical inertness. In this communication, we report on a photoactive, inscribable, nonwettable, and transparent surface (PAINTS), prepared by polycondensation of trichlorovinylsilane to form thin transparent reactive porous nanofilament on a solid substrate. The PAINTS shows superhydrophobicity and can be conveniently functionalized with the photoclick thiol-ene reaction. In addition, we show for the first time that the PAINTS bearing vinyl groups can be easily modified with disulfides under UV irradiation. The effect of superhydrophobicity of PAINTS on the formation of high-resolution surface patterns has been investigated. The developed reactive superhydrophobic coating can find applications for surface biofunctionalization using abundant thiol or disulfide bearing biomolecules, such as peptides, proteins, or antibodies.