Screening for cystic fibrosis via a magnetic and microfluidic immunoassay format with electrochemical detection using a copper nanoparticle-modified gold electrode

SCALA BENUZZI MARÍA LUZ; PEREIRA SIRLEY; RABA JULIO; MESSINA GERMÁN

MIKROCHIMICA ACTA

SPRINGER WIEN

Lugar: Viena; Año: 2015

0026-3672

This article describes a microfluidic electrochemical immunoassay that features two strategies, viz. (a), the incorporation of magnetic nanoparticles (MNPs) into the central microfluidic channel and acting as a bioaffinity support for the immobilization of the antibody against the immunoreactive trypsin (anti-IRT), and (b), the electrodeposition of copper nanoparticles (CuNPs) on a gold electrode. IRT, a marker for cystic fibrosis, is extracted from blood samples onto a disk using ultrasonication, eluted, and then injected into the detection system where it is captured by anti-IRT-loaded nanoparticles (anti-IRT-Ab-MNPs). Bound IRT is electrochemically quantified after addition of HRP-labeled anti-IRT-Ab which, in the presence of H2O2, catalyzes the oxidation of catechol to form o-benzoquinone which is detected at a working potential of −150 mV (vs. Ag/AgCl). The electrochemical response to benzoquinone is proportional to the concentration of IRT in the range from 0 to 580 ng⋅mL−1. The coefficients of variation are