Polymeric and soft materials offer excellent biocompatibility, a high capacity for loading of guest molecules, and cost-effectiveness. Additionally, recent studies on nanodiamonds as quantum materials have revealed interesting applications at ambient temperatures. The attachment of DNA oligonucleotides to these materials enables molecular recognition, directed assembly and targeting capabilities, offering unique advantages for biomedical, analytical and environmental applications. In this article, the mechanisms of DNA adsorption to various metal-free materials, including polydopamine (PDA), hydrogels, microplastics, cellulose crystals, nanodiamonds, and carbon quantum dots are reviewed. Key interactions involved in these systems include π-π stacking, hydrogen bonding, hydrophobic interactions, and metal bridging. We highlight how material properties such as surface charge, functional groups, and wettability influence DNA adsorption and release. Stimuli-responsive systems, such as pH-switchable PDA and thermoresponsive hydrogels, allow controlled DNA adsorption and release. Furthermore, sequence-specific aptamers developed for microplastics and cellulose are discussed, demonstrating the potential for selective DNA binding to nanomaterials. Finally, applications including fluorescence-based biosensors, intracellular delivery, high-density DNA storage, and surface probing are presented. Remaining challenges and future directions are also discussed to guide further advancements in this emerging field.