Highly sensitive surface plasmon resonance immunosensor for parts-per-trillion level detection of 2,4,6-trinitrophenol

Abstract

A new surface plasmon resonance (SPR) immunosensor has been demonstrated for the determination of 2,4,6-trinitrophenol (TNP) based on the principle of indirect competitive immunoreaction using trinitrophenol–bovine serum albumin (TNP–BSA) conjugate and anti-TNP antibody. TNP–BSA conjugate was immobilized on a SPR chip by physical adsorption. TNP in solution competes with the immobilized TNP–BSA conjugate for binding with anti-TNP antibody, which inhibit the immunoreaction between TNP–BSA conjugate and anti-TNP antibody. The dependence of the inhibition to the concentration of TNP was utilized for quantification of TNP. Regeneration of the sensing surface for multiple analyses can be effected using pepsin solution. The sensor exhibited excellent sensitivity for the detection of TNP in a wide concentration range from 10 ppt to 100 ppb and has promising analytical characteristics, which can be extended to the determination of nitroaromatic explosive compounds for application to on-site detection of landmines.