Interfacing DNA and Polydopamine Nanoparticles and Its Applications

Polydopamine (PDA) is polymerized from dopamine under oxidative and basic conditions. PDA is a biocompatible material with great versatility for coating various surfaces and it can also form nanoparticles. DNA oligonucleotides are highly stable, and they can recognize a diverse range of molecules from complementary nucleic acids, proteins to small molecules and metal ions. To enhance the molecular recognition function of PDA, it is interfaced with DNA and the conjugates have achieved a wide range of applications in biomedical and analytical science. In this review, the chemistry of some catecholamines, including dopamine and PDA, is first briefly introduced and variables in the PDA synthesis are highlighted. Strategies to promote DNA adsorption on PDA are then discussed including the use of low pH and polyvalent metal ions. In addition, covalent attachment of DNA to PDA can be achieved by using amino or thiol-modified DNA, forming highly stable conjugates. The specific applications of PDA-DNA conjugate are also delineated, including DNA extraction, biosensing, intracellular delivery, and DNA origami. Finally, some problems in the field are discussed, along with a few future research opportunities.