Nowadays, many detection methods have been explored to detect explosives with high sensitivity and high selectivity. However, it is still a challenge for the researchers to explore a sensor which can ultrasensitively detect the vapor phase explosives and put into practical use with low cost.   

Gas sensors based on nanostructures is a common method to detect vapor phase hazardous chemicals. There are already some attempts on the detection of vapor phase explosives by gas sensing method at present. Optoelectronic sensing of gas phase hazardous chemicals is a newly explored field, which shows great advantages towards low concentration sensing when compared to the normal gas sensing in dark. 

Prof. DOU Xincun's group  from Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences (XTIPC), proposed some new insights to enhance optoelectronic sensing of vapor phase explosives, by employing photocatalysis principles to enhance the sensitivity and employing a molecular imprinting technique (MIT) to enhance the selectivity, which based on their knowledge on optoelectronics, explosives detection, photocatalysis and MIT.  

Researchers found that there are at least two ways can influence charge transfer, and thus cause the change of the measured electric signal. The first one is the charge transfer between the target explosive molecules and photocatalyst. The other one is the charge transfer between the photocatalysis decomposition products and the photocatalyst. They also discussed that MIT might be the first choice to realize selectively photocatalyze the target molecules on the basis of optoelectronic-photocatalysis sensing. MIT will directly improve the accuracy of the detection since molecularly imprinted polymers have a high affinity and selectivity for the adsorption of a special target substance (template molecule). These results would shine light on vapor phase explosives detection. 

The study, funded by the National Natural Science Foundation of China, the “Hundred Talent Program” of CAS, the International Scientific Cooperation Program of Xinjiang etc., is published online in the journal Nanoscale（2013, 5, 10693-10701）as an opinion paper.