Effective Peroxidase-Like Activity of Co-Aminoclay [CoAC] and Its Application for Glucose Detection

Abstract

In this study, we describe a novel peroxidase-like activity of Co-aminoclay [CoAC] present at pH ~5.0 and its application to fluorescent biosensor for the determination of H2O2 and glucose. It is synthesized with aminoclays (ACs) entrapping cationic metals such as Fe, Cu, Al, Co., Ce, Ni, Mn, and Zn to find enzyme mimicking ACs by sol–gel ambient conditions. Through the screening of catalytic activities by the typical colorimetric reaction employing 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid)diammonium salt (ABTS) as a substrate with or without H2O2, Fe, Cu, and CoACs are found to exhibit peroxidase-like activity, as well as oxidase-like activity was observed from Ce and MnACs. Among them, CoAC shows exceptionally high peroxidase-like activity, presumably due to its ability to induce electron transfer between substrates and H2O2. CoAC is then used to catalyze the oxidation of Amplex® UltraRed (AUR) into a fluorescent end product, which enables a sensitive fluorescent detection of H2O2. Moreover, a highly sensitive and selective glucose biosensing strategy is developed, based on enzyme cascade reaction between glucose oxidase (GOx) and CoAC. Using this strategy, a highly linear fluorescence enhancement is verified when the concentration of glucose is increased in a wide range from 10 μM to 1 mM with a lower detection limit of 5 μM. The practical diagnostic capability of the assay system is also verified by its use to detect glucose in human blood serum. Based on these results, it is anticipated that CoAC can serve as potent peroxidase mimetics for the detection of clinically important target molecules.

Site-selective oral delivery of therapeutic antibodies to the inflamed colon via a folic acid-grafted organic/inorganic hybrid nanocomposite system

“…As shown in Fig. 1 C, the FT-IR spectrum of AC showed characteristic peaks of aminopropyl groups (Si–C, 1125 cm −1 ; N–H, 1607 cm −1 ) and the phyllosilicate framework (Si–O–Si, 1030 cm −1 ; Mg–O, Mg–O–Si, 565–500 cm −1 ) 46 , 47 . On the other hand, FA displayed peaks at 1605, 1690, and 1485 cm −1 , corresponding to N–H bending vibration of the CONH group, C=O stretching of carboxyl group, and the absorption band of phenyl ring, respectively 48 .…”

Perspectives for Single-Atom Nanozymes: Advanced Synthesis, Functional Mechanisms, and Biomedical Applications

“…Nanozyme-based biosensors have been successfully designed to detect metal ions (such as Cu 2+ , Ag + , Hg 2+ ), − small molecules (such as H 2 O 2 , , glucose − ), proteins, − nucleic acid, etc. In this section, we will discuss several types of redox enzymes mimicked by SANs, including peroxidase, oxidase, and antioxidase.…”

Magnesium aminoclays as plasmid delivery agents for non-competent Escherichia coli JM109 transformation

“…Sepiolite is a more robust transformation material with more reports in the literature than arginine-glucose functionalized hydroxyapatite nanoparticles and has a 5.9 times higher transformation efficiency than Mg aminoclays using the same host and plasmid (Mendes et al, 2015). However, Mg aminoclays have a higher potential than sepiolite for acquiring enhanced properties that can become a complement to transformation of microorganisms as it has been demonstrated in their use as biosensors (Mann, 2009;Mousty, 2010;Song et al, 2018) or drug delivery nanocarriers (Patil et al, 2005;Patil and Mann, 2008;Chaturbedy et al, 2010;Silva Filho, 2019), making aminoclay-based materials more promising for future implementations of DNA delivery agents since these additional properties can potentially be exploited synergistically with transformation during interaction with cells.…”