Iron tetraphenyl porphyrin functionalized single wall carbon nanotubes for the detection of benzene

Non-covalently functionalized SWNTs with iron tetraphenyl porphyrin (FeTPP) were employed for detection of benzene in a sensing window of 125 ppm at room temperature. Formation of the SWNTFeTPP complex was confirmed by morphological, electrical and field effect studies that revealed an electron donating nature of porphyrin. The SWNTFeTPP sensor showed an average sensitivity of 62% and excellent linearity for validated window of concentration. The typical response and recovery time of the sensor were recorded to be in the order of seconds. In comparison to the sensing behavior of SWNTTPP (tetraphenyl porphyrin) sensor, the SWNTFeTPP sensor exhibited a superior sensing. The central metal ion in case of FeTPP functionalized sensor is found to be instrumental in deciding the sensing behavior.

► SWNTs have been aligned between 3 μm apart Au micropatterns.
► Aligned SWNTs have been non-covalently functionalized by FeTPP and TPP.
► Morphological, electrical and FET studies confirm efficient functionalization.
► Sensing of benzene with FeTPP and TPP functionalized SWNTs were studied.
► SWNTFeTPP shows better sensing revealing active role of central metal ion.