Silica microspheres functionalized with the iminodiacetic acid/copper(II) complex as a peroxidase mimic for use in metal affinity chromatography-based colorimetric determination of histidine-tagged proteins

• Published in: Mikrochimica acta (1966) 2020-02, Vol.187 (2), p.121-121, Article 121
• Main Authors: Gökçal, Burcu, Kip, Çiğdem, Şahinbaş, Dilek, Çelik, Eda, Tuncel, Ali
• Format: Article
• Language: English
• Subjects: Affinity; Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography; Colorimetry; Coordination compounds; Copper; Copper compounds; E coli; Escherichia coli; Evaluation; Fluorescence; Histidine; Microengineering; Microspheres; Nanochemistry; Nanotechnology; Original Paper; Peroxidase; Phenylenediamine; Proteins; Silica; Silicon dioxide; Sorbents; Substrates
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-019-4087-0

Monodisperse porous silica microspheres were functionalized with the iminodiacetic acid/copper(II) complex and then evaluated as a group-specific peroxidase-mimicking nanozyme for colorimetric determination of histidine-tagged (His-tagged) proteins. The green fluorescent protein (GFP) was selected as a typical His-tagged protein. The specificity for GFP and the peroxidase-like activity for the selected substrate were obtained by immobilizing the complex on the porous microspheres. The modified microspheres were also evaluated as a group specific immobilized metal affinity chromatography (IMAC) sorbent for the purification of GFP from Escherichia coli extract. The peroxidase-like activity of the microspheres was inhibited by the GFP adsorbed onto the microspheres due to the interaction of His-tagged protein with the immobilized Cu(II) complex. Ortho-phenylenediamine is used as a substrate for the enzyme mimic. The photometric response (measured at 416 nm) is linear in the 9.0–92 μg·mL −1 GFP concentration range in E. coli lysate. The limit of detection is 6.9 μg·mL −1 . Graphical abstract Schematic representation of metal affinity chromatography-based colorimetric determination of histidine-tagged proteins using silica microspheres functionalized with iminodiacteic acid/copper (II) complex as a peroxidase mimic.