Presentation description

Background: Tuberculosis (TB) is the second deadliest infectious disease, killing 1.6 million people in 2021 alone. Early diagnosis is essential in treating TB. A potential diagnostic method is a breath sensor that aims to detect unique volatile organic compounds (VOC) in the breath of TB patients. Our current sensor uses an electroactive solution (EAS) containing 100mM NaCl and 1mM CuCl2 through which patients breath is bubbled through. Square Wave Voltammetry (SWV) is then used to provide a unique signal depending on the VOCs in the patient's breath that made it to the EAS solution. Purpose: The purpose of this study is to further develop our TB breath sensor by first examining how two known VOC's, N-(2-Aminoethyl)acetamide (AEA) and Phenyl Acetate (PA) react with copper (II) metal salt in the EAS solution. Then, to improve sensor sensitivity, looking at a potential mass transport method using adsorption onto Polyvinyl Alcohol (PVA) to move gaseous VOC's, specifically Methyl Nicotinate (MN), into an aqueous solution. Methods: SWV data of AEA and PA were collected at concentrations of 1mM and 10mM in EAS solutions. This was repeated to validate experimental consistency. PVA films were created by drying an 8 wt% PVA 1.2 wt% NaCl solution, then breath pumped through a 10 mM MN solution was flowed onto the films to adsorb for 20 minutes. The PVA films were then dissolved in an EAS solution upon which SWV and gas chromatography mass separation tests were run to quantify MN in solution. Results: AEA formed a ligand with Cu(2+), reducing the SWV signal drastically, while PA didn't react with Cu(2+). The amount of MN moved to solution through PVA adsorption was shown to be insignificant. Conclusion: We have a better understanding of what VOCs react to our sensor. VOCs with functional groups similar to AEA should be studied further and VOCs with functional groups similar to PA are less likely to react with the sensor. While PVA wasn't a suitable adsorbent, further adsorption studies with other compounds should be conducted.