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In this study, formaldehyde (HCHO)-imprinted hemispherical pore-patterned thin films, consisting of poly(2-(trifluoromethyl)acrylic acid–co–ethylene glycol dimethacrylate–co–styrene) (poly(TFMAA–co–EGDMA–co–ST)), were fabricated using the design of molecularly imprinted polymers (MIPs) and a subsequent lithographic micro/nanoimprinting method to amplify HCHO sensing signals in quartz crystal microbalance (QCM) sensors. Its molecular imprinting condition was optimized by controlling the added amount of a ST monomer in a MIP precursor solution. From the resonant frequency change with respect to HCHO adsorption, the imprinting factor of the porous MIP film was calculated to have a value of 2.38 and the sensitivity (0.132 mg g−1 ppm−1) of the porous MIP film exhibited markedly improved characteristics with respect to the porous non-imprinted polymer (NIP) film (0.05 mg g−1 ppm−1). The selectivity of the MIP-QCM sensors for the detection of HCHO was examined in the presence of other analogous toxic gases such as hydrogen chloride and hydrogen fluoride. The HCHO-absorbed porous MIP film had higher selective features with selectivity coefficients (k* ≈ 3.83 (HCl) and 4.46 (HF)) than porous NIP films (k* ≈ 1.53 (HCl) and 2.20 (HF)). Moreover, the relative selectivity of the porous MIP film appeared to be 2.03–2.5, which was higher than those of the planar MIP film (1.70–1.73).

Owing to the surface interactions at the biomaterial-cell interface inevitable for improved cellular functions, a variety of efforts has been made for the development of the physical and chemical strategies to synchronize and adjust cellular behaviors by utilizing the micro/nanopatterned structures. As one of the most recent emerging nanomaterials, graphene oxide (GO) or reduced GO has increasingly utilized as biocompatible scaffolds, antibacterial films, and biosensor platforms. Here, we report a simple fabrication method for the alternately patterned arrays of the arginine-glycine-aspartic acid (RGD) peptide and GO (RGD/GO) on a single substrate of glass via a sequential process of self-assembly. The responses of fibroblasts to the nanoscopic topographical cues and their preference were explored on the well-separated GO microstructures with or without micropatterned RGD stripes. When separately cultured on those two different arrays of GO and RGD/GO micropatterns, the cells expressed noticeable discrimination in cellular behaviors such as the adhesion, localized population and alignment, and proliferation, according to the presence and absence of alternate RGD patterns. It was also revealed that the GO surface exhibits preferable interactions with cells through the developed focal adhesion sites to the RGD surface. Conclusively, our findings suggest that alternate micropatterns of RGD peptide and graphene family nanomaterials (i.e., GO) may not only be employed for an analyzing device to precisely control the cell migration/motility but also applied in a biosensor interface for electrochemical detection and analysis of cellular responsiveness under a specific external stimulus.

The stainless steel (SS)-based bipolar plate with high conductivity and corrosion resistance is one of the key components in recent polymer electrolyte membrane fuel cells. Therefore, an excellent corrosion protection and good electrical conductivity in SS316L-based bipolar plates can be achieved through plasma-enhanced atomic layer deposition (PEALD) of ultrathin (25–67 nm) TiN thin films. To this end, two types of TiN protective coatings deposited by PEALD using tetrakis(dimethylamino)titanium (TDMAT) and titanium tetrachloride (TiCl4) precursors were evaluated; the evaluations were conducted under conditions simulating the operating conditions of PEMFCs. Regardless of the precursor type, PEALD-TiN onto SS316L resulted in great improvements in electrical conductivity and corrosion resistance. Notably, the TiN thin films prepared using TDMAT exhibited excellent corrosion resistance (