Zirconium-Based Porphyrinic Metal-Organic Framework (PCN-222): Enhanced Photoelectrochemical Response and Its Application for Label-Free Phosphoprotein Detection.

A simple and rapid photoelectrochemical (PEC) sensor was developed for the label-free detection of a phosphoprotein (α-casein) based on a zirconium based porphyrinic metal-organic framework (MOF), PCN-222, which exhibited an enhanced photocurrent response toward dopamine under the O2-saturated aqueous media. In this work, in terms of PEC measurements and cyclic voltammetry, the PEC behaviors of PCN-222 in aqueous media were thoroughly investigated for the first time. Additionally, in the virtue of the steric hindrance effect from the coordination of the phosphate groups and inorganic Zr-O clusters as binding sites in PCN-222, this biosensor showed high sensitivity for detecting α-casein and the limit of detection (LOD) was estimated to be 0.13 μg mL-1. Moreover, the proposed method provides a promising platform for clinic diagnostic and therapeutics.