Synthesis of a Co₃O₄@gold/MWCNT/polypyrrole hybrid composite for DMMP detection in chemical sensors

Chemical sensors based on a nanocrystalline Co₃O₄/gold@MWCNT/polypyrrole decorated hybrid composite were fabricated, and their sensitivity properties to stimulant dimethylmethylphosphonate (DMMP) were characterized. The hybrid composite was decorated by a hydrothermal process in the presence of cobalt/gold precursors, and the characteristics were determined by Raman, XRD, XPS, SEM-EDX, and FE-TEM analysis. The cyclability and linearity of the detection response for chemical sensors in the presence of DMMP vapor were determined by using a crystal microbalance. The hybrid composite material should possess excellent selectivity, stability, and reasonable sensitivity in the presence of N₂ gas at room temperature for DMMP detection. The response of the composite showed retainability when exposed to the DMMP component, due to the high resistance response, fast response time, rapid recovery, and good reproducibility.