Using monoclonal antibody to determine lead ions with a localized surface plasmon resonance fiber-optic biosensor

A novel reflection-based localized surface plasmon resonance (LSPR) fiber-optic probe has been developed to determine the heavy metal lead ion concentration. Monoclonal antibody as the detecting probe containing massive amino groups to capture Pb(II)-chelate complexes was immobilized onto gold nanoparticle-modified optical fiber (NMAuOF). The optimal immobilizing conditions of monoclonal antibody on to the NMAuOF are 189 mu g/mL in pH7.4 PBS for 2 h at 25 degrees C. The absorbability of the functionalized NMAuOF sensor increases to 12.2% upon changing the Pb(II)-EDTA level from 10 to 100 ppb with a detection limit of 0.27 ppb. The sensor retains 92.7% of its original activity and gives reproducible results after storage in 5% D-(+)-Trehalose dehydrate solution at 4 degrees C for 35 days. In conclusion, the monoclonal antibody-functionalized NMAuOF sensor shows a promising result for determining the concentration of Pb(II) with high sensitivity.