Toward Handheld Diagnostics of Cancer Biomarkers in Breath: Micro Preconcentration of Trace Levels of Volatiles in Human Breath

This paper introduces, for the first time, Maltese-cross pillar design implemented in a 7 mm × 7 mm × 0.35 mm cavity for high-performance microfabricated preconcentrators (μPCs). This high-aspect ratio design provides more surface area over the previously reported basic geometric shapes. Results showed that Maltese-cross provided a 27% increase in performance. Moreover, reducing the pillar spacing from 100 μm to 10 μm and arranging the pillars in staggered fashion have resulted in 145% and 85% increase in performance, respectively. Therefore, it was concluded that both surface area and flow pattern contribute significantly to the device performance. These μPCs achieved high adsorption capacity making them suitable for handheld breath analyzers to concentrate and identify trace-level (low ppb) volatile compounds (cancer biomarkers) found in human breath.