Serafín González-Carrato, VerónicaAgüí Chicharro, María LourdesYáñez-Sedeño Orive, PalomaPingarrón Carrazón, José Manuel2024-01-252024-01-252013Serafín V, Agüí L, Yáñez-Sedeño P and Pingarrón J.M. Electrochemical immunosensor for the determination of insulin-like growth factor-1 based on carbon nanotubes – poly(pyrrole propionic acid) hybrids. Biosens. Bioelectron. 2013 Agosto 29; 52: 98-1040956-566310.1016/j.bios.2013.08.021https://hdl.handle.net/20.500.14352/95376An amperometric immunosensor for the determination of the hormone insulin-like growth factor 1 (IGF1) is reported for the first time in this work. As electrochemical transducer, a multiwalled carbon nanotubes-modified glassy carbon electrode on which poly(pyrrole propionic acid) was electropolymerized was prepared. This approach provided a high content of surface confined carboxyl groups suitable for direct covalent binding of anti-IGF1 monoclonal antibody. A sandwich-type immunoassay using a polyclonal antibody labeled with peroxidase, hydrogen peroxide as the enzyme substrate and catechol as redox mediator was employed to monitor the affinity reaction. All the variables involved in the preparation of the modified electrode were optimized and the electrodes were characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Moreover, the different experimental variables affecting the amperometric response of the immunosensor were also optimized. The calibration graph for IGF1 showed a range of linearity extending from 0.5 to 1000 pg/mL, with a detection limit, 0.25 pg/mL, more than 100 times lower than the lowest values reported for the ELISA immunoassays available for IGF1 (30 pg/mL, approximately). Excellent reproducibility for the measurements carried out with different immunosensors and selectivity against other hormones were also evidenced. A commercial human serum spiked with IGF1 at different levels between 0.01 and 10.0 ng/mL was analyzed with good results.engAttribution-NonCommercial-NoDerivatives 4.0 Internationaljournal articlehttps://doi.org/10.1016/j.bios.2013.08.021https://pubmed.ncbi.nlm.nih.gov/24035852/restricted access544.6Electrochemical immunosensorInsuline-like growth factor 1Poly(pyrrole propionic acid)Química analítica (Química)2301 Química Analítica