Flexible porous aerogel decorated with Ag nanoparticles as an effective SERS substrate for label-free trace explosives detection
Sensitive and reliable method for explosives detection is regarded as significance in homeland security, due to the serious threats of explosives in terrorist attack events. However, such suitable sensor is still rare. Herein, porous silica aerogel decorated with silver nanoparticles (SiO2-Ag hybrids) was prepared and applicated as flexible SERS substrates for ultrasensitive explosives detection. It is worth noted that the silica aerogel we prepared had good flexibility compared with traditional silica aerogel, which effectively avoided structural damage during collecting samples. Also, because of excellent adsorption performance provided by silica aerogel, trace explosives 3-nitro-1,2,4-triazol-5-one (NTO) could be enriched, and realized the label-free detection. Combined with the plasma enhancement provided by Ag NPs decorated around these porous, the limit of detection for explosives NTO was as low as 7.94×10-10 M. As far as we know, this aerogel SiO2-Ag hybrids SERS substrate was firstly used in the detection of explosives. It presented good sensitivity and reproducibility for the analytes sensing. Most importantly, it is a label-free method for trace explosives detection, and has a good application prospect in homeland security.