RT Journal Article
T1 Dextran-coated nanoparticles as immunosensing platforms: Consideration of polyaldehyde density, nanoparticle size and functionality
A1 Gao, Shipeng
A1 Torrente Rodríguez, Rebeca M.
A1 Pedrero Muñoz, María
A1 Pingarrón Carrazón, José Manuel
A1 Campuzano Ruiz, Susana
A1 Rocha Martin, Javier
A1 Guisán, José M.
AB Magnetic nanoparticles (MNPs) can be used as antibody carriers in a wide range of immunosensing applications. The conjugation chemistry for preparing antibody-MNP bionanohybrids should assure the nanoparticle’s colloidal dispersity, directional conformation and high biofunctionality retention of attached antibodies. In this work, peroxidase (HRP) was selected as model target analyte, and stable antibody-MNP conjugates were prepared using polyaldehyde-dextrans as multivalent linkers, also to prevent nanoparticles agglomeration and steric shielding of non-specific proteins. Under the manipulation of the oxidation variables, MNP-conjugated antibody showed the highest Fab accessibility, of 1.32 μmol analyte per μmol antibody, corresponding to 139 μmol aldehyde per gram of nanocarrier (5 mM NaIO4, 4 h). Demonstrating anti-interference advantage up to 10% serum, colorimetric immunoassay gave a detection limit (LOD) of 300 ng mL− 1 , while electrochemical transduction led to a considerable (680 times) improvement, with a LOD of 0.44 ng mL− 1 . In addition, polyaldehydedextran showed priority over polycarboxylated-dextran as the multivalent antibody crosslinker for MNPs in terms of sensitivity and LOD value, while immunosensors constructed with carboxylated magnetic microbeads (HOOC-MBs) outperformed MNPs-based immunoplatforms. This work sheds light on the importance of surface chemistry (type and density of functional groups) and the dimension (nanosize vs micrometer) of magnetic carriers to conjugate antibodies with better directional orientation and improve the analytical performance of the resulting immunosensors.
PB Elsevier
SN 0039-9140
YR 2022
FD 2022-05-21
LK https://hdl.handle.net/20.500.14352/71496
UL https://hdl.handle.net/20.500.14352/71496
LA eng
NO CRUE-CSIC (Acuerdos Transformativos 2022)
NO Ministerio de Ciencia e Innovación (MICINN)
NO Comunidad de Madrid
NO China Scholarship Council
DS Docta Complutense
RD 20 jul 2024