The analysis of specific VOC in exhaled breath (identified as biomarkers of specific disease like cancer)give an idea of metabolic and physiological activities of an individual and can provide non-invasive andpotentially inexpensive anticipated diagnosis of several diseases including cancer. The invention of afast, reliable, economic and portable technique is highly required before breath testing become a clinicalreality. Nanomaterial based sensor arrays can fulfill all these requirements and can form a solidfoundation for identification of disease related VOC patterns in exhaled breath. The objective of thisthesis was to fabricate different chemo-resistive sensors based on conductive nanocomposites withability to differentiate and discriminate a set of disease (such as lung cancer) biomarker VOC. Thereforein order to fabricate high performance sensors with high sensitivity and required selectivity towardstargeted VOC, adoption of different methodologies for the synthesis of conductive nanocomposite, wasstrongly emphasized.Covalent and noncovalent functionalizations of these carbon nanomaterials with various oligomeric,polymeric or inorganic molecules were done in order to tune the sensor’s selectivity and sensitivity.Nanoswitching at the junctions of percolated network formed by the carbon nanomaterials could becontrolled by varying the organic functionality on the surface.Finally a set of high performance chemoresistive vapour sensors, with different selectivity towardstargeted lung cancer VOC could be fabricated and successfully integrated in an e-nose with highefficiency towards detection and discrimination of a set of disease specific VOC biomarkers.