Sliver-Nanoparticle Enhanced Pva Thin-Film Colorimetric Humidity Sensor

In this paper, a fast-response colorimetric humidity sensor based on silver-nanoparticle (AgNP) enhanced polyvinyl alcohol (PVA) thin-film interferometer is reported. The AgNPs are directly printed on a titanium dioxide (TiO
₂
) capped quartz substrate via precision photoreduction technology. Compared with a single layer of PVA film, this PVA-AgNP-TiO
₂
structure displays more brilliant and abundant colors. The colorimetric sensor can rapidly respond to humidity change in air, and the measured rise time of response is 87 ms. Such fast-response colorimetric sensors have great potential for many applications, such as breath analysis and smartphone camera-based biochips.