Biotin-avidin binding was detected using Xe NMR.

Inhibitory effect of xenon biosensor binding to avidin.

Comparison of the exchange of xenon gas with the biosensor cage when the biosensor molecule is in the free state (b) and when bound to avidin (9).

(A) Structures of ABAO derivatives that contain propargyloxy group and biotin. (B) Quantification of the reaction of BABAO with the M13 phage displaying a library of peptides with N-terminal glyoxal and wt phage displaying no aldehyde (1011 PFU/mL each). (C) Phage mixture was exposed to BABAO for the specified time. (D) To measure the reaction rate, we exposed the mixture of phage to 1 mM BABAO and measured biotinylation as a function of time by avidin capture. Error bars represent standard deviations from four independent kinetics experiments.