Sensitive TNT Detection Using QCM Via Competition Assay

There have been many systems which have been designed for the detection of the explosive 2, 4, 6-trinitrotoluene (TNT). The current state of the art sensing schemes achieves high sensitivity, but low selectivity, which makes detection of TNT in a dirty environment difficult. Here we show how to combine a protein competition assay with quartz crystal microbalance (QCM) by using an anti-TNT antibody to detect TNT in small quantities and distinguish it from similar molecules. QCM is chosen due to its high sensitivity as a mass measurement sensor. ELISA (Enzyme-linked immunosorbent assay) is used to evaluate the competition assay for TNT detection and offer a comparison to the QCM results. Due to its label-free, real-time measurements, a TNT sensor based on a competition assay on QCM results in detection with high sensitivity and selectivity. Furthermore, this method could be also applied to detect other chemicals, such as environmental pollutants.