An effective approach to fabricate high strength polyurethane hydrogels with reversible photochromic performance as a photoswitch

Photochromic hydrogels have attracted widespread attention because of their potential applications in optical devices. Spiropyran (SP) is one of the most investigated organic photochromic compounds, which have high sensitivity to...

Colorimetric Detection of Nitroaromatics Using Organic Photochromic Compounds

An organic photochromic compound is explored as a new portable colorimetric sensor for nitroaromatics. This photochromic compound switches from colourless to pink upon exposure to ultraviolet light. In the presence of nitroaromatic explosive derivatives the photoswitching behaviour of the dithienylethene is suppressed, while a potential false positive (toluene) has little effect. The degree of photoswitching inhibition was determined by comparing the integrated visible absorption with the concentration of the analyte to give the pseudo Stern–Volmer constant (KPSV). The KPSVs measured varied from 12900 (p-nitrotoluene) to 236 M–1 (toluene), which were directly related to the analyte absorption at the excitation wavelength.