Nanostructured and functionalized cantilever for sensing organophosphorous compounds

Vertically aligned TiO
₂
nanorods have been successfully synthesized on the micrometric surface of a cantilever by a two-step procedure involving solvothermal method. Adjusting TiO
₂
synthesis conditions, first optimized on centimetric silicon substrate, allowed to well-control the morphology of the nanorods, aimed to increase the collection surface of this micromechanical sensor. By using the nanostructured microcantilever for the detection of organophosphorous agent (OPs), a frequency shift of 833 Hz corresponding to a remarkable enhancement of the sensor sensitivity by a factor of 75 compared to a pristine cantilever is achieved. Moreover, functionalization of this nanostructured cantilever with a tailored functional oxime molecule having strong affinity with OPs compounds significantly improved the performance of the sensor in vapor phase. A frequency shift of 1319 Hz is obtained at 500 ppm of DMMP with the functionalized sensor.