SPR analysis was used to determine the overall equilibrium dissociation constant (KD) of Hf-BTB-NH2 nanosheets towards these peptides and the data is summarized in Table . The dried nanosheets were suspended in 1 mL of the running buffer (PBS pH 7.4 and 0.01 % Tween 20), with the addition of sodium acetate for SPR analysis. A planar polyethylene glycol/carboxyl coated Au chip was activated using NHS and EDC, followed by the addition of the nanosheet dispersion. Finally, a quenching solution of ethanolamine was used to deactivate any unreacted carboxyl groups and wash away any unbound nanosheets.