Selectivity of organic nanocomposite sensor for detection of aldehydes

Organic molecule based sensor for detection of aldehydes is fabricated and tested. Organic molecules chemiresistor sensors are low cost sensors and operate at low temperature. The sensing element of the chemiresistor fabricated is a blend of o-phenylene diamine (OPD)-carbon black (CB) nanocomposite. The selectivity of the sensor to volatile organic compounds - aldehyde, ketone and alcohol is studied. The sensor response was recorded at a concentration of 8000 ppm. The sensor shows good response to aldehydes. The higher response for aldehyde is attributed to the interaction of the carbonyl oxygen of aldehydes with amine group of OPD. The surface morphology of the sensing element is studied by scanning electron microscopy. The interaction of the VOCs with the OPD-CB nanocomposite is also studied by molecular dynamics studies. The interaction energies of the analyte with OPD-CB nanocomposite were calculated. It is observed that the interaction energies for aldehydes are higher than for other anlaytes. Thus the OPD-CB sensor shows selectivity to aldehydes. The selectivity of the sensor to aldehydes shows that it can be used as an aldehyde sensor.