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.

抗体-金纳米颗粒（Ab-AuNP）生物共轭物在生物传感领域得到了广泛的应用。这促使研究人员建立各种策略，将抗体与金纳米颗粒偶联。最佳的缀合至关重要，因为Ab-AuNP生物缀合物应稳定，同时保持抗体识别和结合其相应抗原的能力。尽管如此，抗体在AuNPs上的高覆盖度是构建灵敏生物传感器的关键步骤，但是理想的覆盖度需要与结合抗体的方向和可及性完美平衡。在这篇综述中，我们打算为读者提供一些关键要素，使他们能够掌握Ab与AuNP的结合并在分子水平上合理化，涉及的机制以及预期的抗体覆盖范围和方向。我们将重点研究与球形AuNPs偶联的IgG型抗体，因为这些生物偶联物是生物传感器最常用的抗体。首先，我们报告了共轭方法的详尽调查，通过物理吸附和化学吸附策略。然后，我们提供了对相关策略的关键性恢复，从而可以通过生物缀合物的直接分析或上清液的间接分析来量化金纳米颗粒上抗体的覆盖范围。在最后一部分中，我们回顾并讨论了这些Ab-AuNP生物共轭物在光学生物传感中的选定应用。