Oligopeptides functionalized surface plasmon resonance biosensors for detecting thiacloprid and imidacloprid

By using phage display library, we identified two highly specific oligopeptide sequences RKRIRRMMPRPS and RNRHTHLRTRPR for binding neonicotinoids such as thiacloprid and imidacloprid. The former shows high affinity for thiacloprid whereas the latter shows high affinity for imidacloprid. Surprisingly, cross binding is minimal despite the similarity of the two molecules. To develop a neonicotinoid biosensor, these two oligopeptides are synthesized and immobilized on the surface of a surface plasmon resonance (SPR) chip with a bare-gold surface. This oligopeptide functionalized SPR biosensor can rapidly detect thiacloprid and imidacloprid in buffer solutions in a real-time manner. The limit of detection (LOD) for thiacloprid and imidacloprid is 1.2 μM and 0.9 μM, respectively.

► We identified an oligopeptide RKRIRRMMPRPS for binding thiacloprid with high specificity.
► We also identified another oligopeptide RNRHTHLRTRPR for binding imidacloprid with high specificity.
► No cross-binding was observed for these two oligopeptides with their targets.
► A SPR biosensor for detecting thiacloprid and imidacloprid was developed.