AVS 59th Annual International Symposium and Exhibition | |
Biomaterial Interfaces | Wednesday Sessions |
Session BI+SS+NS-WeM |
Session: | Bio/Nano Interfaces with Applications in Biomedicine and Energy |
Presenter: | F. Zang, University of Maryland |
Authors: | F. Zang, University of Maryland H. Ben-Yoav, University of Maryland X. Fan, University of Maryland A. Brown, University of Maryland J. Culver, University of Maryland R. Ghodssi, University of Maryland |
Correspondent: | Click to Email |
Detection of chemical hazards and explosive compounds has received growing attention for applications in environmental monitoring, food science, and national security. Explosives, such as TNT, show low vapor pressure, molecular mass, and volume, which makes the detection of these molecules challenging for most mass and refractive index based sensors. Thanks to the redox reaction of nitro groups in TNT molecules, electrochemical methods may be used for detection of low concentrations of TNT in aqueous environments. Electrochemical sensors are suited for on-site explosive detection due to high sensitivity, low volume and convenient integration with miniaturized devices. However, to distinguish TNT from other electrochemically active compounds in complex environments, high selectivity is a more critical factor for development of TNT sensors.
In preliminary studies, background signals generated from electrolytes were characterized and the signal-to-noise ratio was optimized by long term scans of square wave voltammetry. Three concentration dependent current peaks from the reduction of nitro groups in TNT were observed at the potentials of -0.53V, -0.72V and -0.86V vs. Ag/AgCl reference electrode, respectively, which agreed with the results in literatures. The initial results showed a stable and reliable electrochemical response by the TMV-p sensing system. By comparing the reduction currents in the mixtures of TMV-p and unmodified TMV with TNT solutions, we will demonstrate that TMV-p preserves the peptide binding affinity to TNT molecules while increasing the binding site density.