Detection of mixed volatile organic compounds and lung cancer breaths using chemiresistor arrays with crosslinked nanoparticle thin films

The ability to create sensing thin films for chemiresistors using crosslinked nanoparticle thin films with subtle structural differences in terms of interparticle linker molecular structure, nanoparticle composition and size is important not only for tuning sensitivity and selectivity in constructing a sensor array but also for enhancing stability of the sensors under ambient sensing conditions. In this report, we show that arrays of chemiresistors with such subtle structural differences are viable for detecting mixed volatile organic compounds (VOCs) and breath biomarkers under ambient conditions. The sensor arrays exhibit nanostructure-tunable sensitivity to VOCs and mixtures, with a limit of detection as low as 20 ppb easily achievable for acetone. Preliminary testing of the sensor array in detecting breath samples from limited lung cancer patients, which consists of certain mixed VOCs as biomarkers, has also demonstrated the capability of breath recognition of lung cancer patients from healthy individuals under ambient sensing conditions. The recognition statistics were analyzed, showing the potential viability of achieving the desired sensitivity, selectivity, and accuracy in the breath sensing, the implication of which is discussed in terms of optimization of the sensor arrays for potential lung cancer screening.