title: Revisiting catechol derivatives as robust chromogenic hydrogen donors working in alkaline media for peroxidase mimetics.
abstract: Colloidal noble metal-based nanoparticles are able to catalyze oxidation of chromogenic substrates by H2O2,similarly to peroxidases, even in basic media. However, lack of robust chromogens, which work in high pH impedes their real applications. Herein we demonstrate the applicability of selected catechol derivatives: bromopyrogallol red (BPR) and pyrogallol (PG) as chromogenic substrates for peroxidase-like activity assays, which are capable of working over wide range of pH, covering also basic values. Hyperbranched polyglycidol-stabilized gold nanoparticles (HBPG@AuNPs) were used as model enzyme mimetics. Efficiency of several methods of improving stability of substrates in alkaline media by means of selective suppression of their autoxidation by molecular oxygen was evaluated. In a framework of presented studies the impact of borate anion, applied as complexing agent for PG and BPR, on their stability and reactivity towards oxidation mediated by catalytic AuNPs was investigated. The key role of high concentration of hydrogen peroxide in elimination of non-catalytic oxidation of PG and improvement of optical properties of BPR in alkaline media containing borate was underlined. Described methods of peroxidase-like activity characterization with the use of BPR and PG can become universal tools for characterization of nanozymes, which gain various applications, among others, they are used as catalytic labels in bioassays and biosensors.
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Drozd
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland. Electronic address: mariusz@ch.pw.edu.pl.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Pietrzak
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Pytlos
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland; Biotechnology Platform, CEZAMAT, Polna 50, 00-644, Warsaw, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Malinowska
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D018716:Molecular Mimicry; D010544:Peroxidases / Q000737:chemistry*
chemical_list: D000468:Alkalies; D002396:Catechols; D006046:Gold; D006859:Hydrogen; D006861:Hydrogen Peroxide; D010544:Peroxidases
keywords: Borate complexes; Bromopyrogallol red; Catalytic activity; Gold nanoparticles; Peroxidase; Pyrogallol