Colloidal crystal-PDMS composite VOCs sensor with modified initial interparticle distance

It is necessary to develop low-end sensors to detect volatile organic compounds (VOCs), which are harmful to human body in real life as well as industrial environment. However, conventional colorimetric-based sensors have shown shortcomings in terms of response time, sensitivity and selectivity. To overcome the difficulties, this study proposes a novel method for highly sensitive photonic crystal (PC) based VOC sensor by increasing the intimal distance between nanoparticles. Silicon liquid is used to change the initial interdistance by chemical swelling, and it is fixed by replacing the swollen space with premixed PDMS. As a result, more color change (handgap shift) occurs as the initial interparticle distance increases, and the performance improved up to 24.0 %.