Micro-interfaces modulation by UV-ozone substrate treatment for MPEA vapor fluorescence detection

Drug abuse directly endangers human health and social security,hence its sensitive and rapid detection is vitally important.In recent years,organic film-based fluorescent sensing technology has attracted more and more attention in the detection of drugs and explosives due to its advantages of simple operation and rapid detection.For film-based fluorescent sensors,in addition to sensitive materials,the surface morphology of the film is also an important factor affecting the performance.In previous studies,the regulation of surface morphology mainly depends on concentration changes or complex templates.Here,a novel fluorescent polymer probe was designed and synthesized,and a simple and efficient ultraviolet(UV)-ozone substrate treatment method is used to adjust their surface morphology.The results show that film has an excellent fluorescence enhancement effect upon exposure to methylphenethylamine(MPEA,a simulant of methamphetamine)vapor.The sensing effect of the film is significantly improved after UV-ozone substrate treatment,and the limit of detection was decreased by 10.4 times from 2.59 to 0.25 ppm.Further experiments show that the sensing performance of other fluorescent probe can also be improved by the UV-ozone substrate treatment.This convenient and general method may become a very effective approach to improve the performance of film-based fluorescent sensors.

Multifunctional Semiconducting Fibers for Visual Detection of Sarin Gas

There is a growing need for protective instruments that can be used in extreme environments,including those encountered during exoplanet exploration,anti-terrorism activities,and in chemical plants.These instruments should have the ability to detect external threats visually and monitor internal physiological signals in real time for maximum safety.To address this need,multifunctional semiconducting fibers with visual detection ranging from yellow to red and near-field communication(NFC)capabilities have been developed for use in personal protective clothing.A composite conductive yarn with semiconducting fluorescent probe molecules is embroidered on the clothing,forming an NFC coil that allows for the visual monitoring of atmospheric safety through color changes.The fluorescence detection system was able to selectively detect diethyl chlorophosphate(DCP),a substitute for the toxic gas sarin,with a detection limit of 6.08 ppb,which is lower than the life-threatening concentration of sarin gas.Furthermore,an intelligent protective suit with the abovementioned dual functions was fabricated with good mechanical cycle stability and repeatability.Real-time physiological signals such as the temperature and humidity of the wearer could be read through the NFC conveniently.Such intelligent protective suits can quickly provide an early warning to the identified low-dose DCP and evaluate the health of wearer according to the changes in physiological signals.This study offers a smart,low-cost strategy for designing intelligent protective devices for extreme environments.