Extrusion, electrospinning, and microdrawing are widely used to create fibrous polymer mats, but these approaches offer limited access to oriented arrays of nanometer-scale fibers with controlled size, shape, and lateral organization. We show that chemical vapor polymerization can be performed on surfaces coated with thin films of liquid crystals to synthesize organized assemblies of end-attached polymer nanofibers. The process uses low concentrations of radical monomers formed initially in the vapor phase and then diffused into the liquid-crystal template. This minimizes monomer-induced changes to the liquid-crystal phase and enables access to nanofiber arrays with complex yet precisely defined structures and compositions. The nanofiber arrays permit tailoring of a wide range of functional properties, including adhesion that depends on nanofiber chirality.

Whispering-gallery mode (WGM) microdisk lasers show great potential for highly sensitive label-free detection in large-scale sensor arrays. However, when used in practical applications under normal ambient conditions, these devices suffer from temperature fluctuations and photobleaching. Here we demonstrate that these challenges can be overcome by a novel referencing scheme that allows for simultaneous compensation of temperature drift and photobleaching. The technique relies on reference structures protected by locally dispensed passivation materials, and can be scaled to extended arrays of hundreds of devices. We prove the viability of the concept in a series of experiments, demonstrating robust and sensitive label-free detection over a wide range of constant or continuously varying temperatures. To the best of our knowledge, these measurements represent the first demonstration of biosensing in active WGM devices with simultaneous compensation of both photobleaching and temperature drift.

We report a metal-free radical perfluoroalkylation method which uses inexpensive and commercially available perfluorocarboxylic anhydrides as an easy to use source of perfluoroalkyl radicals.

Antimicrobial peptides (AMPs), due to their unique structure/function relationship, have great opportunities to be developed into novel diagnostic and therapeutic agents for a variety of pathogens and illnesses. Often such peptides are administered using powder or suspension, limiting their reusability or recyclability. Immobilization of these antimicrobial peptides on biotic/abiotic surfaces may circumvent such disadvantages, but such immobilization is likely to not only change the peptide secondary structures and their orientations but also ultimately affect functionality. In order to better understand surface-bound structures of AMPs on abiotic surfaces, cecropin A (1−8)−melittin (1−18) hybrid peptides were chemically immobilized on polymer surfaces prepared by chemical vapor deposition (CVD) polymerization. Measurements by sum frequency generation (SFG) vibrational spectroscopy and circular dichroism were used to characterize the peptides immobilized on the CVD-based polymer in situ. In addition, coarse-grained molecular dynamics (MD) simulations were used to understand the orientation of these peptides on the molecular level. Simulation results were highly consistent with experimental data. Results indicated that, unlike other linear peptides immobilized on similar abiotic surfaces, this hybrid peptide immobilized on CVD-based polymer surfaces exhibited two bending points. Such conclusions help further understand the role surface immobilization for such unique molecules.

The preparation of stimuli‐responsive aminomethyl functionalized poly(p‐xylylene) coatings by chemical vapor deposition polymerization is reported. Modification of the paracyclophane precursor with ionizable aminomethyl groups leads to polymer coatings with pH‐responsive swelling properties. The swelling behavior is monitored in situ using spectroscopic ellipsometry and additional streaming potential measurements are performed. With decreasing pH‐value, the coating becomes increasingly charged and reversibly swells to several times its dry thickness. The swelling ratio is sensitive to the ionic strength of the solution. By using a mixture of unfunctionalized and functionalized precursors in the chemical vapor deposition process, the number of charges in the polymer layer can be tuned and with it the swelling ratio of the coating. As a proof‐of‐concept for possible applications, a commercial paper filter is coated. This results in a pH‐dependent wetting behavior and pH‐dependent transport through the capillaries of the paper.