Literature review in Biosensors & Bioelectronics on AuNP-Ab BioconjugatesAntibody-Gold Nanoparticle Bioconjugates for Biosensors: Synthesis, Characterization and Selected Applications

How to attach an antibody to AuNP? What strategies and what efficiency? How many Ab can one AuNP accomodate?
Find some answers to these questions in our literature Review just accepted in Biosensors & Biolectronics tackling Antibody-Gold nanoparticle Bioconjugates for Biosensors applications

DOI : 10.1016/j.bios.2020.112370

Abstract

Antibody-Gold  nanoparticle  (Ab-AuNP)  bioconjugates are  widely  used  in  the  field  of biosensing.  This  prompted  researchers  to  set  up  various  strategies  to  conjugate antibodies to gold nanoparticles. Optimal conjugation is of critical importance, as the Ab-AuNP bioconjugates should be stable while maintaining the ability of the antibody to recognize and bind its corresponding antigen. All the same, a high coverage of antibodies on AuNPs is a key-step to build up a sensitive biosensor, but an ideal coverage requires to  be  perfectly  balanced  with  the  orientation  and  accessibility  of  the  conjugated antibodies.  In  this  review,  we  intend  to  provide  the  reader  with  the  key  elements allowing for mastering the conjugation of Ab to AuNP and rationalizing, at the molecular level,  the  mechanisms  involved  together  with  the  expected  antibody  coverages  and orientations.  We  will  focus  on  IgG-type  antibodies conjugated  to  spherical  AuNPs  as these bioconjugates are the most commonly used ones for biosensors. First, we report an exhaustive survey of the methods of conjugation, via strategies of physisorption and chemisorption. Then we provide a critical restitution of the relevant strategies allowing the quantification of antibodies coverage on gold nanoparticles either through direct analysis of the bioconjugates or indirect analysis of the supernatant. In the last part, we review  and  discuss  selected  applications  of  these  Ab-AuNP  bioconjugates  in  optical biosensing.