Concentration and Detection of Hydrophobic Analytes using Modified Paper-SERS

Abstract

Surface Enhanced Raman Spectroscopy (SERS) has been used to measure trace quantities of analytes and cost-effective paper-based SERS substrates have been used in the field to detect heroin and fentanyl in low-resource settings. However, due to the inherent properties of paper and the manufacturing process, these SERS substrates have limited capabilities in detection of lipophilic and hydrophobic analytes. This is of critical importance in markets such as the detection of delta9-THC, which is found in trace amounts (parts per billion) in saliva of intoxicated drivers. In this defense, I will show the how the paper-based SERS substrate manufacturing process can be modified to allow for the detection of hydrophobic analytes. Then, I will show how an alternative detection protocol can be applied to concentrate and measure larger volumes of hydrophobic analytes in an aqueous solution.