Manganese Porphyrin-dsDNA Complex: A Mimicking Enzyme for Highly Efficient Bioanalysis

Abstract

Manganese porphyrin (MnTMPyP)-dsDNA complex was reported as an excellent mimicking enzyme of peroxidase. It possessed high catalytic activity and much quicker catalytic kinetics and better stability with exposure to light irradiation and high temperature than both horseradish peroxidase and hemin/G-quadruplex DNAzyme. The groove binding of MnTMPyP to the dsDNA scaffold efficiently maintained the catalytic activity of the MnTMPyP center and improved its stability. By combining with an isothermal hybridization chain reaction (HCR) and in situ formation of MnTMPyP-dsDNA, a highly efficient chemiluminescent (CL) immunosensing method was proposed. After a sandwich immunoreaction, a biotinylated DNA strand, which was bound to biotinylated signal antibody by streptavidin, triggered the HCR and growth of MnTMPyP-dsDNA on the immunocomplex. The in situ, HCR-assisted enzyme formation brought numerous enzymatic catalytic centers, MnTMPyP, on the immunocomplex, resulting in significant CL signal amplification and highly sensitive CL detection. Using carcinoembryonic antigen as the model target, the proposed CL immunoassay method showed a wide linear range from 10 pg/mL to 100 ng/mL with a detection limit of 6.8 pg/mL. The new MnTMPyP-dsDNA complex could be conveniently synthesized, functionalized, and combined with DNA amplification strategies, showing a promising potential in bioanalysis and other relative fields.

Improved method for chemiluminescent determination of peroxidase-mimicking DNAzyme activity

“…But the high cost of the native enzyme has stimulated a search for its alternatives. Some peroxidase mimetics such as hemin, porphyrins, phthalocyanines, and metal nanoparticles have shown a peroxidase-like activity [1][2][3][4][5][6][7][8][9].…”

Signal Amplification for Highly Sensitive Immunosensing

“…Xu et al [47] designed a mimicking enzyme with peroxidase-like activity by loading MnTMPyP in the dsDNA scaffold. This complex possessed high catalytic activity and much quicker catalytic kinetics and better stability with exposure to light irradiation and high temperature than both horseradish peroxidase and hemin/G-quadruplex DNAzyme.…”

β-Cyclodextrin as a Metal-anionic Porphyrin Complexation Accelerator in Aqueous Media

“…[1][2][3][4][5][6][7][8][9] In addition, metal-porphyrin complexes have various functions that are useful in analytical chemistry, and are also of interest to many other researchers, which has led to the use of metal-porphyrin complexes in applications such as optics, 10 chemical stacking, 11 catalysis, 12 electron transport, 13 oxidation-reduction reactions, 14 and biological mimicking substances. 15,16 Thus, numerous reports regarding the chemical function and applications of porphyrin derivatives have been published.…”