Enhancing breath analysis with a novel AuNP-coated cotton sensor

Human health has always been a major concern for science. Over the years, health research has included different areas, ranging from specific therapies to patients' lifestyle and social information: 'patient-oriented' approaches have increasingly emerged as a crucial tool for health care systems, as clearly shown during the recent SARS-CoV-2 pandemic. In this context, the synergy between different scientific and technological fields, such as biology, chemistry, physics, and engineering, is increasingly considered an essential requirement. This work presents a low cost and easy-to-use sensor of volatile organic compounds (VOCs) in exhaled breath, with the purpose of serving as a rapid, non-invasive and versatile diagnostic tool in smart medicine applications. A 'lock-and-key' system relying on gold nanoparticles deposited on cotton fabric enables the detection of target molecules, whose adsorption produces variations in terms of electrical impedance. The system has been exposed to ethanol-based solutions in an experimental campaign to investigate the sensing capabilities at 1 Hz - 1 MHz frequency range. The results achieved demonstrate the feasibility in obtaining health-relevant VOCs detection based on impedance analysis.