title: Alzheimer's disease biomarkers detection in human samples by efficient capturing through porous magnetic microspheres and labelling with electrocatalytic gold nanoparticles.
abstract: A nanobiosensor based on the use of porous magnetic microspheres (PMM) as efficient capturing/pre-concentrating platform is presented for detection of Alzheimer's disease (AD) biomarkers. These PMMs prepared by a multistep swelling polymerization combined with iron oxide precipitation afford carboxyl functional groups suitable for immobilization of antibodies on the particle surface allowing an enhanced efficiency in the capturing of AD biomarkers from human serum samples. The AD biomarkers signaling is produced by gold nanoparticle (AuNP) tags monitored through their electrocatalytic effect towards hydrogen evolution reaction (HER). Novel properties of PMMs in terms of high functionality and high active area available for enhanced catalytic activity of the captured AuNPs electrocatalytic tags are exploited for the first time. A thorough characterization by scanning transmission electron microscope in high angle annular dark field mode (STEM-HAADF) demonstrates the enhanced ability of PMMs to capture a higher quantity of analyte and consequently of electrocatalytic label, when compared with commercially available microspheres. The optimized and characterized PMMs are also applied for the first time for the detection of beta amyloid and ApoE at clinical relevant levels in cerebrospinal fluid (CSF), serum and plasma samples of patients suffering from AD.
authors.affiliation: ICN2 - Nanobioelectronics & Biosensors Group, Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, Bellaterra (Barcelona) 08193, Spain.
authors.forename: Alfredo
authors.initials: A
authors.lastname: de la Escosura-Muñiz
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovského Sq. 2, Prague 6 162 06, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Plichta
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovského Sq. 2, Prague 6 162 06, Czech Republic.
authors.forename: Daniel
authors.initials: D
authors.lastname: Horák
authors.affiliation: ICN2 - Nanobioelectronics & Biosensors Group, Institut Catala de Nanociencia i Nanotecnologia, Campus UAB, Bellaterra (Barcelona) 08193, Spain; ICREA - Institucio Catalana de Recerca i Estudis Avançats, Barcelona 08010, Spain. Electronic address: arben.merkoci@icn.cat.
authors.forename: Arben
authors.initials: A
authors.lastname: Merkoçi
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000032:analysis*; D001057:Apolipoproteins E / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D002384:Catalysis; D003217:Conductometry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008863:Microspheres; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D015415:Biomarkers; D006046:Gold
keywords: Alzheimer disease biomarker; Electrochemical immunoassay; Gold nanoparticles; Hydrogen evolution reaction; Porous magnetic microspheres