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 (CoIII-PPIX@Py2CD) was achieved via covalent linkage between CoIII of CoIII-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 CoIII-PPIX. X-ray photoelectron spectroscopy (XPS) was employed to affirm the binding of the as-obtained CoIII-PPIX@Py2CD, whose electrochemical kinetics were extensively studied to validate the feasibility in the catalytic reduction of hydrogen peroxide (H 2 O 2). The developed sensor displayed the wide linear range for H 2 O 2 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. Image 1 • Py2CD was obtained by the covalent linkage of two β-CDs monomers with 3,5-bis (bromomethyl) pyridine. • The CoIII-PPIX@Py2CD were prepared by acyl chlorination reaction between the CoIII of CoIII-PPIX and pyridine N of Py2CD. • The catalyst dramatically improved the electronic conductivity and amplified the catalytic signals towards H 2 O 2 reduction. • An ultrasensitive chronoamperometric sensor was developed for H 2 O 2 detection. [ABSTRACT FROM AUTHOR]