Dr. Chiranjit Ghosh, Ph.D. 

I am an analytical chemist and my research area is the sample preparation, mass spectrometry, material chemistry and clinical chemistry. During my first postdoctoral position at professor Janusz Pawliszyn’s research group, I worked on developing two microsorbent chemical devices, called thin film membrane device and needle trap device, using solid-phase microextraction techniques for capturing more than a hundred reported metabolic marker compounds associated with various diseases from the human breath tests. Later, these devices were coupled to portable GC-MS and this configuration enabled us to integrate sampling, sample preparation and finally analysis of breath biomarkers in a single platform. Our designed breath-based analytical devices were utilized for on-site point-of-care detection of lungs cancer marker compounds at the Toronto General Hospital, Canada (S. Zeinali, C. Ghosh and J. Pawliszyn, Analytica Chimica Acta, 1203:339671, 2022). To make our technique more versatile and sensitive, we incorporated polyvinylidene difluoride, a thermally stable polymeric material in our material-based coating recipe during the development of the mentioned devices. This revised configuration of the devices made us possible for both gas chromatography and liquid chromatography mass spectrometry applications through a single channel (USA Patent, 16/704426, C. Ghosh, V. Singh, J. Grandy and J. Pawliszyn). For further application in environmental field, we have utilized one of the devices to develop a purge-and-trap analytical technique for the on-site monitoring of the level of butylated hydroxy toluene (BHT) compound from the skin lubricants. To further validate this technique, we randomly checked the toxicity level (as per guidelines by the Cosmetics Ingredient Review Board) of the following compound from the random cosmetics samples from the Canadian market (C. Ghosh, V. Singh, J. Grandy and J. Pawliszyn, RSC Advances, 6671, 10, 2020).

After spending almost 2yrs at the University of Waterloo, I joined at Dr. Koo’s research group in the Harvard Medical School & Mass General Brigham, USA. Here, I am working on developing the passive and active sampling tools by utilizing polymeric sorbent materials to capture the microbial emitted volatile metabolites, especially sesquiterpene levels in breath for screening of the fungal and bacterial infection in the immunocompromised cancer patients. This study is based on the fact that the certain microbial and host volatile metabolites are present in the breath of patients with pneumonia caused by bacterial and fungal pathogens, providing a diagnostic target for these pneumonias. Furthermore, the components of the metabolites profile that is microbial in origin will respond to effective antibiotic or antifungal therapy and disappear from the breath; conversely, the components will not disappear, and instead potentially increase, in patients receiving ineffective antimicrobial therapy - this will effectively provide a rapid, in vivo assessment of resistance or ineffective antimicrobial therapy in real time, allowing clinicians to switch antimicrobial therapy in a rational manner. In Harvard, we have developed a bedside portable thermal desorption-gas chromatography-differential mass spectrometer for on-site detection of pneumonia in the cancer patients from the exhaled breath metabolites pattern analysis.