Molecular Simulations and Theory for the Prediction of Analyte Specificity in Polymer-wrapped Carbon Nanotube Sensors

Zachary Ulissi, Massachusetts Institute of Technology

The fluorescence of single-walled carbon nanotubes (SWCNTs) can be used as molecular chemical sensors, but only when wrapped with a polymer that allows only specific molecules of interest to interact with the nanotube surface. Our lab has developed a range of polymer wrappings that allow for the specific detection of a range of biologically important molecules, including nitric oxide, hydrogen peroxide and glucose. The mechanism for molecular specificity of these sensors is still an open question and new wrappings are developed primarily through a physical understanding of analyte-polymer interactions and high-throughput testing. Here we present a simple thermodynamic model for predicting the surface coverage of polymers and analytes on a nanotube surface, as well as a molecular dynamics-based method for automatically determining the necessary model parameters of arbitrary analytes of interest given the molecular structure. We compare results using this method to an extensive experimental library of over 400 sensor-analyte interactions. Future applications of these methods include the computational screening of analytes that can work with our existing polymer-SWCNT sensors.

Abstract Author(s): Zachary Ulissi, Jingqing Zhang, Shangchao Lin, Daniel Blankschtein, Michael Strano