Kinetic Analysis Using SPR. Kinetic analysis was initiated by injection of the running buffer PBST (blank) onto the Hf-BTB-NH2 immobilised sensor surface for 2 minutes, followed by PBST for 5 minutes. The binding kinetics of an individual Hf-BTB-NH2 nanosheet to the selected target was determined from serial dilutions (five concentrations, 4-64 nM) of the selected target under study. Each dilution was injected for 2 minutes (association) followed by PBST for 5 minutes (dissociation). After dissociation, the target was removed from the immobilized surface by injecting regeneration buffer (10 mM Glycine-HCl, pH 2) for 1 minutes followed by PBST for 1 minutes. The same procedures were repeated for the remaining four dilutions of the target. After the analyses were completed, signals from the left channel were subtracted from signals from their respective reference channel (the right channel).