Integration of MOF/COF core-shell composite material with wrinkled supramolecular hydrogel: A portable electrochemical sensing platform for noradrenaline bitartrate detection

Abstract

Predictably integration of rigid powder nanocrystals with flexible soft materials for rapid, accurate and portable detection of biological small molecules is an ongoing goal of researchers. In this research, the MOF/COF core-shell composite material (MIL-88B(FeCu)/COF) was constructed via monomer-mediated solvothermal approach. Subsequently, the MIL-88B(FeCu)/COF was effectively combined with chitosan-acrylamide based wrinkled supramolecular hydrogel to form a unique rigid-flexible composite material (MIL(FeCu)/COF@Hy). Next, the noradrenaline bitartrate (NB) was selected as a target molecule for electrochemical behavioral assessment. Of note, the portable electrochemical sensing platform constructed in this study does not require the use of solutions (chitosan or Nafion) to seal the electrode materials, and the portable device provides sufficient convenience for NB detection. And the excellent linear window (0.06–10 and 10–1600 μmol/L), sensitivity (0.0645 and 0.0729 μA μM cm−2), detection limit (0.02 μmol/L) and anti-interference stability can be achieved. The outstanding electrochemical behaviors may be ascribed to: 1) hydrogel matrix significantly improves the dispersion of MOF/COF composite materials and avoids its agglomeration; 2) there are abundant diffusion paths in the hydrogel nanocomposite; 3) the synergistic catalytic effect of MOF/COF and hydrogel. In short, the combination of this heterostructured MOF/COF composite materials and hydrogel soft materials will provide a valuable reference for the rapid detection of biomolecules.