Rationally designed nucleobase and nucleotide coordinated nanoparticles for selective DNA adsorption and detection.

Nanomaterials for DNA adsorption are useful for sequence-specific DNA detection. Current materials for DNA adsorption employ electrostatic attraction, hydrophobic interaction, or π-π stacking, none of which can achieve sequence specificity. Specificity might be improved by involving hydrogen bonding and metal coordination. In this work, a diverse range of nucleobase/nucleotide (adenine, adenosine, adenosine 5'-triphosphate (ATP), adenosine 5'-monophosphate (AMP), and guanosine 5'-triphosphate (GTP)) coordinated materials containing various metal ions (Au(III), Ag(I), Ce(III), Gd(III), and Tb(III)) are prepared. In most cases, nanoparticles are formed. These materials have different surface charges, and positively charged particles only show nonspecific DNA adsorption. Negatively charged materials give different adsorption kinetics for different DNA sequences, where complementary DNA homopolymers are adsorbed faster than other sequences. Therefore, the bases in the coordinated materials can still form base pairs with the DNA. The adsorption strength is mainly controlled by the metal ions, where Au shows the strongest adsorption while lanthanides are weaker. These materials can be used as sensors for DNA detection and can also deliver DNA into cells with no detectable toxicity. By tuning the nanoparticle formulation, enhanced detection can be achieved. This study is an important step toward rational design of materials to achieve specific interactions between biomolecules and synthetic nanoparticle surfaces.