A novel and effective natural product-based immunodetection tool for TNT-like compounds

This study aimed to develop a fast and reliable protocol for Trinitrophenol-Tris(hydroxymethyl)aminomethane (TNP-Tris) detection applying a β-lactamase-fusion protein of choice, the natural product-based immunoreagent tool of competitive sensitivity developed herein for the first time. Since the fusion protein 11B3-scFv-β-lactamase is constructed from a scFv-antibody (11B3) linked to an enzyme (β-lactamase), the step related to the use of secondary antibody in the enzyme-linked immunosorbent assay (ELISA) is completely omitted. Indeed, this fusion protein itself serves both as binding mean of the antigen model and detecting agent, due to the presence of the naturally occurring enzyme. In such a way, it actually affords the one-step TNP-Tris detection reaching a promising LOD value of 45 ± 2 fmol or 157 ± 6 pg/mL. Taken all together, the current protocol does represent much cheaper and significantly less-time consuming alternative compared both to the recombinant antibodies and recombinant phages, previously designed means in our labs for the same purpose.