DNA Stickers Promote Polymer Adsorption onto Cellulose

Adsorption of oligonucleotides onto model cellulose surfaces was investigated by comparing the Boese and Breaker's cellulose binding oligonucleotide (CBO) with a nonspecific oligonucleotide control (NSO). Measurements using the quartz crystal microbalance with dissipation technique confirmed that CBO adsorbed onto cellulose more than NSO, particularly at high ionic strengths (100 mM CaCl(2)). CBO showed a higher maximum adsorption on nanofibrillated and nanocrystalline cellulose than on regenerated cellulose, indicating a preference for the native cellulose I crystal structure under conditions that favored specific adsorption over calcium-mediated electrostatically driven adsorption. In addition, an anionic polyacrylamide (A-PAM) with grafted CBO also adsorbed onto the surface of cellulose in CaCl(2), whereas the unmodified A-PAM did not. This work shows that CBO performs as a "sticker", facilitating the adsorption of polyacrylamide onto cellulose, even under high ionic strength conditions where the adsorption of conventional polyelectrolytes is inhibited.