Porphyrin-Based Nanomaterials: Enhanced Electrochemiluminescence and the Application of Bioassay

Abstract

Electrochemiluminescence (ECL) has become a powerful analytical tool and has been widely applied in many fields. However, ECL still has shortcomings like poor ability to repeatedly electrochemically cycle an individual luminophore, a broad emission spectroscopy, and signal loss due to ECL reagents leaving the detection zone. Therefore, further improvement of ECL signal is still of significance. Nanomaterials can be incorporated into ECL sensor to improve efficiency, but also represent a new class of ECL emitters. Porphyrins are 18p aromatic azaannulenes consisting of regularly arranged four methine carbons. Electrochemical and photochemical properties of porphyrins have attracted much attention for decades because of their unique aromatic structure and their beneficial characteristics such as high molar absorptivity, as well as the vital roles in biological processes such as photosynthesis, oxygen transport, and biocatalysis. Porphyrins have a flexible and adjustable molecular structure in chemical modification. The introduction of molecular-recognition motifs (e.g., hydrogen bonding, metal-ligand bonds andp-pstacking) into the porphyrin building blocks will make them form new structures, such as fibers, cubes, sheets, simple micelles and wheels. In our work, we have developed several enhanced ECL sensors based on porphyrin-nanocomposite. For example, we synthesized zirconium-based porphyrinic metal−organic framework (MOF) for the detection of a phosphoprotein. The active center ZnTCPP in MOF-525-Zn as electron media reacts with O2 in the 3D nanocage to produce 1O2, resulting in enhanced ECL signal. Figure 1