The mimetic assembly of cobalt prot-porphyrin with cyclodextrin dimer and its application for H₂O₂ detection

A biomimetic assembly of per-O-methylated-cyclodextrin dimer with cobalt proto-porphyrin (Co^III-PPIX@Py2CD) was achieved via covalent linkage between Co^III of Co^III-PPIX and pyridine N of Py2CD (primarily synthesized by the acyl chlorination reaction of two β-CDs monomers with 3,5-bis (bromomethyl) pyridine). Ultraviolet-visible (UV-vis) and circular dichroism (CD) absorption spectroscopy, and NMR hydrogen spectroscopy (H¹-NMR) were adopted to carefully characterize the structure of Py2CD and its functional assembly with Co^III-PPIX. X-ray photoelectron spectroscopy (XPS) was employed to affirm the binding of the as-obtained Co^III-PPIX@Py2CD, whose electrochemical kinetics were extensively studied to validate the feasibility in the catalytic reduction of hydrogen peroxide (H₂O₂). The developed sensor displayed the wide linear range for H₂O₂ detection and the low detection limit of 2.47 × 10^-7 M. This work sheds some constructive lights on rational design and synthesis of preeminently biomimic carrier and high cost-effectiveness catalyst for (bio)analytical applications.