Expanding the Dynamic Range of Surface-enhanced Raman Scattering (SERS) Biosensors

Abstract

Record ID: 232

Award(s): Excellence in Research Communication

Program Affiliation: Capstone

Presentation Type: Poster

Abstract: Biosensors function by using biological and chemical components to detect a broad range of analytes, such as nucleic acids, antibodies, and small molecules like glucose. Among biosensors, those based on surface-enhanced Raman scattering (SERS) have superior multiplexing capabilities that can detect a broad range of targets simultaneously. However, sensors (including SERS biosensors and lateral flow assays) are often used only for yes/no answers and do not provide important quantification information (e.g., viral load). This limitation is due to the small dynamic range (range of detectable target concentrations), which is of 1-2 orders of magnitude. This project focuses on expanding the dynamic range of SERS biosensors from the current 1 order of magnitude concentration range to 4-5 orders of magnitude. In this project, we altered the design features and sequences of DNA-based SERS biosensors to see how these modifications affected the sensitivity and limit-of-detection of these sensors compared to a benchmark previously developed sensor. The sensors were then tested over a wide range of concentrations to determine the dissociation constant (KD), dynamic range and limit-of-detection of each sensor. We analyzed the data to determine the optimal mixture of sensors that gives the widest and most linear dynamic range. This optimal mixture was then validated by showing that the optimal mixture of sensors has great linearity over more than 4 orders of magnitude. We demonstrated how altering different features of the DNA-based sensors affects figures-of-merit. We also demonstrated that combining multiple sensor designs can greatly increase the dynamic range and quantification capabilities.