Dynamic Interaction between Host and Guest for Enantioselective
Recognition: Application of β‑Cyclodextrin-Based Charged
Catenane As Electrochemical Probe
posted on 2019-04-09, 00:00authored byDatong Wu, Yong Kong
Charged
catenane has attracted ever increasing attention as prototypical
molecular switches in their synthesis and function. In this study,
β-cyclodextrin and ionic liquid mechanical interlocking with
each other are carried out to form charged catenane through ionic
hydrogen bonding. When the charged catenane is treated with Cu(II)
ion, it will generate blue precipitate quickly with a rigid and robust
structure. Given that the synthesized molecule bears good electroactivity
and stability, it is used as a modifier on the surface of the bare
glassy carbon electrode and further performs as an electrochemical
probe. The probe shows a clear chiral discrepancy in the response
of oxidation peak current (IP) toward
four isomers, including tryptophan, tyrosine, cysteine, and malic
acid. That is, l form has a much higher IP and, currently, it is hard to observe the electrochemical
signal for d form. More interestingly, the recognition ability
between l and d forms of tryptophan can be reversed
in the buffer solution with different pH values. These results show
that the dynamic switch process of steric hindrance based on the catenane
can enlarge the chiral discrepancy. In a word, we believe that this
study would enrich the synthetic pathways of electroactive molecules
and lead to a deeper fundamental understanding of their function.