A hand-held device for determining presence of a volatile compound (VC) in or content of at least one gaseous sample, the device comprising at least two detachable parts , wherein a first part comprises a sample collecting chamber ; and a second part comprises at least one sensor assembly ; wherein the sample collecting chamber and the at least one sensor assembly are in gaseous communication; the device further comprising a closed loop channel assembly and a pump configured to direct said sample from the sample collecting chamber to the at least one sensor assembly and to circulate said sample from the sample collecting chamber over the at least one sensor assembly over a period of time; wherein the circulation is continuous back to and from the collection chamber and over the sensor assembly to maintain a stable and continuous measurement; and an analyzer configured for real-time analysis of the VC presence in or content of the sample; and a data processing unit for data communication with the sensor assembly; a data user interface unit being in data communication with the data processing unit; wherein the data processing unit comprising data relating to a control data set and is adapted to receiving from the at least one sensor assembly information relating to presence of VCs or pattern thereof and provide an indication of presence or absence of one or more VCs, and disease state wherein the at least one sensor assembly comprises a plurality of sensing regions and wherein optionally one or more of said at least two detachable parts are disposable, wherein each of the plurality of sensing regions is provided with a plurality of nanoparticles associated to a surface of each of the plurality of sensing regions and wherein the nanoparticles are surface-associated with a plurality of VC interacting ligand molecules. the sample collecting chamber and the at least one sensor assembly are in gaseous communication; the device further comprising a closed loop channel assembly and a pump configured to direct said sample from the sample collecting chamber to the at least one sensor assembly and to circulate said sample from the sample collecting chamber over the at least one sensor assembly over a period of time; wherein the circulation is continuous back to and from the collection chamber and over the sensor assembly to maintain a stable and continuous measurement; and an analyzer configured for real-time analysis of the VC presence in or content of the sample; and a data processing unit for data communication with the sensor assembly; a data user interface unit being in data communication with the data processing unit; wherein the data processing unit comprising data relating to a control data set and is adapted to receiving from the at least one sensor assembly information relating to presence of VCs or pattern thereof and provide an indication of presence or absence of one or more VCs, and disease state wherein the at least one sensor assembly comprises a plurality of sensing regions and wherein optionally one or more of said at least two detachable parts are disposable, wherein each of the plurality of sensing regions is provided with a plurality of nanoparticles associated to a surface of each of the plurality of sensing regions and wherein the nanoparticles are surface-associated with a plurality of VC interacting ligand molecules. <EOS>