| Abstract
| - We demonstrate a self-assembled reagentless biosensorbased on a modular design strategy that functions in thedetection of TNT and related explosive compounds. Thesensor consists of a dye-labeled anti-TNT antibody fragment that interacts with a cofunctional surface-tetheredDNA arm. The arm consists of a flexible biotinylated DNAoligonucleotide base specifically modified with a dye andterminating in a TNB recognition element, which is ananalogue of TNT. Both of these elements are tethered toa Neutravidin surface with the TNB recognition elementbound in the antibody fragment binding site, bringing thetwo dyes into proximity and establishing a baseline levelof fluorescence resonance energy transfer (FRET). Addition of TNT, or related explosive compounds, to the sensorenvironment alters FRET in a concentration-dependentmanner. The sensor can be regenerated repeatedly throughwashing away of analyte and specific reformation of thesensor assembly, allowing for subsequent detection events.Sensor dynamic range can be usefully altered through theaddition of a DNA oligonucleotide that hybridizes to aportion of the cofunctional arm. The modular design ofthe sensor demonstrates that it can be easily adapted todetect a variety of different analytes.
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