From the article: "A facile approach for the fabrication of large-scale interdigitated nanogap electrodes (nanogap IDEs) with a controllable gap was demonstrated with conventional micro-fabrication technology to develop chemocapacitors for gas sensing applications. In this work, interdigitated nanogap electrodes (nanogap IDEs) with gaps from 50–250 nm have been designed and processed at full wafer-scale. These nanogap IDEs were then coated with poly(4-vinyl phenol) as a sensitive layer to form gas sensors for acetone detection at low concentrations. These acetone sensors showed excellent sensing performance with a dynamic range from 1000 ppm to 10 ppm of acetone at room temperature and the observed results are compared with conventional interdigitated microelectrodes according to our previous work. Sensitivity and reproducibility of devices are discussed in detail. Our approach of fabrication of nanogap IDEs together with a simple coating method to apply the sensing layer opens up possibilities to create various nanogap devices in a cost-effective manner for gas sensing applications"
MULTIFILE
Sensor platforms can benefit from the incorporation of polymerbrushes since brushes can concentrate the analyte near the sensor surface. Brushesthat absorb acetone vapor are of particular interest since acetone is an importantmarker for biological processes. We present a simple procedure to synthesize acetoneresponsivepoly(methyl acrylate) brushes. Using spectroscopic ellipsometry, we showthat these brushes respond within seconds and swell by more than 30% when exposedto acetone vapor. Moreover, quartz crystal microbalance measurements demonstrate that the brushes can be exploited to increasethe acetone detection sensitivity of sensors by more than a factor 6. Surprisingly, we find that the swelling ratio of the brushes inacetone vapor is independent of the grafting density and the degree of polymerization of the polymers in the brush. This isqualitatively different from swelling of the same brushes in liquid environments, where the swelling ratio decreases for increasinggrafting densities. Yet, it indicates that the brushes are robust and reproducible candidates for implementation in vapor sensorsystems.
MULTIFILE
In a long-term project, together with Courage, we are investigating whether it is possible to determine volatile fatty acids, methane or acetone in the air blown from dairy cows. These substances are associated with health and digestion of the cow. We are working on a sensor together with tech partners and we compare measured values in breathing air with both activity measurements with the Nedap sensors and with manual health scores. In een langlopend project bekijken we samen met Courage of het mogelijk is om in uitgeblazen lucht van melkkoeien vluchtige vetzuren, methaan of aceton te bepalen. Deze stoffen zijn geassocieerd met gezondheid en vertering van de koe. Samen met tech-partners werken we aan een sensor en we vergelijken gemeten waardes in ademlucht met zowel activiteitsmetingen met de Nedap sensoren als met handmatige gezondheidsscores.
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