A Robust Tripeptide for In-Field Selective Naked Eye Ultratrace Detection of 2,4,6-Trinitrophenol

A simple and cost-effective peptide-based in-field detection of the nitro explosive 2,4,6-trinitrophenol (TNP) in the solution, solid, and vapor state at very low concentration has been developed. In solution, the peptide experiences huge fluorescence quenching even at the ppb level concentration of TNP. The fluorescence turn-off process is governed by the charge transfer complex formation with TNP, almost immediately. Moreover, the probe exhibits very high selectivity and low interference of other analogues nitro explosives toward the detection of TNP. The detection can be done in-field at any condition such as in the solution state, solid state, as well as vapor state with a paper strip device and can be observed by the naked eye, which is necessary for a real-time explosive detector without any sophisticated and expensive instruments with a quicker response time.