GC-MS enabled biomarker identification and electrodeposition empowered metal oxide-based e-nose at close to body temperature for colorectal cancer early diagnosis by profiling isopropanol from stool sample

Colonoscopy is considered as a gold standard for a long term but its bowel preparation and painful process as well as recovery process leads to researchers to find alternative method to manage such a disease. Current methods are limited due to false positive such as genetic-based gene screening from collected feces sample. This research has used feces sample and to collect its headspace profile and revealed that isopropanol and para-cresol are two of biomarkers extracted from stool sample that can be used to differentiate the healthy donor and diseased ones in a sample size of totaling 135 volunteers, including 55 non-neoplasia, 44 adenoma, and 36 colorectal cancer (CRC) patients from the First Affiliated Hospital of Soochow University. The further constructed electrodeposited zinc oxide-based chemiresistive on gold substrate has provided tuned Schottky barrier, enabling easier electron transfer, resulting in a selective, sensitive and reproducible sensing results among n-propanol, 1-butanol, ethanoic acid and propanoic acid. It revealed that three major miller indices including (-1, 0, 0), (0, 0, 2) and (-1, 0, −1) contributes synergistically for enabling low temperature (40 ℃) detection with a limit of detection (LOD) at 6.50 ppm and limit of quantification (LOQ) at 21.46 ppm in the detection range of 1.17–117 ppm.