General Fluorimetric Flow-through Sensor for the Determination of Oxidase Substrates

Abstract

A new flow-through sensor for the determination of hydrogen peroxide based on the dual immobilisation of the catalyst and the reaction product (permanent immobilisation in a reactor and transient retention in the flow-cell, respectively) is proposed. The support packed in the flow-cell is an aminopropyl-bonded silica gel non-fluorescent material. The approach provides a linear range between 0.03–17 ng ml^–1 H₂O₂ (r² = 0.9954, RSD values less than 3.5%). This sensor is 80 times more sensitive than a photometric flow-through biosensor previously reported and based on similar principles.