Au Nanostars Coated with a Thin Film of MIL-100 (Fe) for SERS-Based Sensing of Volatile Organic Compound Indicators in Saliva

Mortality of gastric cancer is the second in cancer-associated deaths due to the lack of specific symptoms at an early stage, and thus, early detection of gastric cancer is receiving more attention. Nowadays, volatile organic compound (VOC) indicators have been found to be helpful for screening a variety of cancers. Meanwhile, hybrid VOC indicators, namely, VOCs derived from both human breath and body fluids, provide more information about health status. Nevertheless, details of VOCs in body fluid (e.g. saliva) are still unclear and tracking of these VOCs remains a challenge. In this research, 10 kinds of VOCs released from the saliva were reported to be potential indicators for gastric cancer prewarning. To track these potential indicators with high specificity, a surface-enhanced Raman scattering (SERS) sensor based on a thin layer of MIL-100 (Fe) shell-wrapped Au nanostars (Au-star) was developed, and part of the aforementioned VOC indicators (e.g., 2-butanone, eucalyptol, and isopropanol) were found to be selectively detected by the sensor. These pilot results indicate a bright future for the proposed strategy for disease screening and the design of future high-performance SERS sensors.