Gold nanoparticles (AuNPs) are a type of widely used nanomaterials with unique chemical and physical properties. AuNPs can be readily synthesized, and modified with various chemical or biological molecules, making them promising candidates for catalysis, drug delivery and biological imaging applications. In this review, we mainly focus on recent advances in the design and synthesis of conjugates of AuNPs by exploiting biomolecule-AuNP interactions. We will also discuss a variety of bioapplications of AuNP-based conjugates.