Flexible chemiresistive sensor of polyaniline coated filter paper prepared by spraying for fast and non-contact detection of nitroaromatic explosives

摘要

Both bending stability and high sensitivity are two important problems to be solved in developing flexible sensors. The flexible sensor based on flower-like polyaniline coated filter paper (PCFP) was developed by spraying for the first time, achieving the non-contact and fast detection of nitroaromatic explosives. Hierarchical structure, high permeability of filter paper and the interaction between amino groups of PANI and nitro groups of nitroaromatic explosives contributed to the sensitive and fast response to 2, 4, 6-trinitrotoluene (TNT), picric acid (PA) and 2, 4-dinitrotoluene (DNT) at room temperature. The responses of PCFP to TNT, PA and DNT run up to about 237.7, 100.6 and 80.1%, respectively. The average response time and recovery time to TNT, PA and DNT are no more than 8.1 and 1.9 s, respectively. The theoretical limit of detection for TNT and PA is 0.094 and 0.029 ppb, respectively. More importantly, the special interlaced flower-like structures of polyaniline contributed to the good flexural stability. The response fluctuation to TNT, PA and DNT do not exceed 7% in the bending process and the decreases of responses are less than 7.9% after 2000 bends of 40 degrees. In addition, the spraying method is suitable for economical, efficient and large-scale preparation of paper-based flexible sensors.