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 g/mL in pH7.4 PBS for 2 h at 25 °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 °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.