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In this study, flexible calorimetric gas sensors are developed for specific detection of gaseous hydrogen peroxide (H 2 O 2 ) over a wide concentration range, which is used in sterilization processes for aseptic packaging industry. The flexibility of these sensors is an advantage for identifying the chemical components of the sterilant on the corners of the food boxes, so-called "cold spots", as critical locations in aseptic packaging, which are of great importance. These sensors are fabricated on flexible polyimide films by means of thin-film technique. Thin layers of titanium and platinum have been deposited on polyimide to define the conductive structures of the sensors. To detect the high-temperature evaporated H 2 O 2 , a differential temperature setup is proposed. The sensors are evaluated in a laboratory-scaled sterilization system to simulate the sterilization process. The concentration range of the evaporated H 2 O 2 from 0 to 7.7% v/v was defined and the sensors have successfully detected high as well as low H 2 O 2 concentrations with a sensitivity of 5.04 C/% v/v. The characterizations of the sensors confirm their precise fabrication, high sensitivity and the novelty of low H 2 O 2 concentration detections for future inline monitoring of food-package sterilization.

The aim of this study was to assess the impact of nanocrystalline diamond (NCD) thin coatings on neural cell adhesion and proliferation. NCD was fabricated on fused silica substrates by microwave plasma chemical vapor deposition (MPCVD) method. Different surface terminations were performed through exposure to reactive hydrogen and by UV induced oxidation during ozone treatment. Boron doped NCD coatings were also prepared and investigated. NCD surface wettability was determined by contact angle measurement. To assess biocompatibility of the NCD coatings, the neuroblastoma SH-SY5Y cell line was used. Cells were plated directly onto diamond surfaces and cultured in medium with or without fetal bovine serum (FBS), in order to evaluate the ability of cells to adhere and to proliferate. The obtained results showed that these cells adhered and proliferated better on NCD surfaces than on the bare fused silica. The cell proliferation on NCD in medium with and without FBS after 48h from plating was on average, respectively, 20 and 58% higher than that on fused silica, irrespective of NCD surface modification. Our results showed that the hydrogenated, oxygenated and boron-doped NCD coatings can be used for biomedical purposes, especially where good optical transparency is required.

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