Quantum dots (QDs) coupled with biomolecules play an important role as optically and chemically stable bioimaging agents for various applications. These inorganic-biological hybrid conjugates have been demonstrated as powerful fluorescence tools for sensing, diagnostics, and labeling. This review focuses on protein-QD nanohybrids for different types of bioanalytical applications. There are various strategies to modify the surface properties of QDs to produce protein-QD nanohybrids that are stable in biological fluids. We expect that multifunctional protein-QD nanohybrids can be used as a powerful optical probe for various biological applications. WIREs Nanomed Nanobiotechnol 2016, 8:178-190. doi: 10.1002/wnan.1345 For further resources related to this article, please visit the.