Self-Cascade Nanoenzyme of Cupric Oxide Nanoparticles (CuO NPs) Induced in Situ Catalysis Formation of Polyelectrolyte as Template for the Synthesis of Near-Infrared Fluorescent Silver Nanoclusters and the Application in Glutathione Detection and Bioimaging

Abstract

In this work, near-infrared fluorescent silver nanoclusters (Ag NCs) were prepared based on the in situ formed poly methacrylic acid (PMAA) as the template and stabilizer, which is synthesized by methacrylic acid (MAA) and hydroxyl radical (·OH) that is generated by the cascade nanoenzyme reaction of cupric oxide nanoparticles (CuO NPs). CuO NPs possess the intrinsic glutathione-like (GPx-like) and peroxidase-like (POD-like) activities, which can catalyze glutathione (GSH) and O2 to produce hydrogen peroxide (H2O2), and then transform into ·OH. The fluorescence intensity of Ag NCs decreases with the addition of GSH, because the −SH can easily anchor on the surface, resulting in the PMAA leaving the Ag NCs, and the coeffect of GSH and PMAA results in the aggregation to form larger Ag NPs. A good linear relationship between the fluorescence quenching rate and the GSH concentration was found in the range 0.01–40 μM with the detection limit 8.0 nM. The Ag NCs can be applied in the detection of GSH in the serum, as well as bioimaging of endogenous and exogenous GSH in cells with high sensitivity. Moreover, the normal and cancer cells can be distinguished through bioimaging because of the different GSH levels. The new method for the preparation of biocompatible nanoprobe based on the nanozyme tandem catalysis and the in situ formed template can avoid the direct usage of polymers or protein templates that hinder preparation and separation, providing a reliable approach for the synthesis, biosensing, and bioimaging of nanoclusters.

Selective and sensitive on-site colorimetric detection of 4,4′-isopropylidenediphenol using non-enzymatic molecularly imprinted graphitic carbon nitride hybrids in milk and water samples

“…Yaxin et al , developed CuO NPs possess the intrinsic glutathione-like (GPx-like) and peroxidase-like (POD-like) activities, which can catalyze glutathione (GSH) and O 2 to produce hydrogen peroxide (H 2 O 2 ), and then transform into ˙OH. 46 The POD-like activity of a CuO NP-POM (polyoxometalate) nanocomposite, a colorimetric sensing platform for ascorbic acid (AA) depending on the fact that AA can efficiently react with the oxidation product of TMB, which was catalyzed by CuO NP-POM on the basis of the POD-like activity. 47 Likewise, the CuO nanoparticle-modified Zr-MOF exhibits POD-like activity obtained due to the Zr 4+ in UiO-66 is beneficial to the aggregation of CuO NPs on its surface.…”

Near-infrared rhodol dyes bearing salicylaldehyde moieties for ratiometric pH sensing in live cells during mitophagy and under hypoxia conditions

“…A549 cells were grown in modified Eagle's (Gibco) medium accompanied with 10% fetal bovine serum (Fisher Scientific) at 37 °C under a 5% CO 2 moistened air environment and then further cultured until an 80% confluence was reached. 8,10,11,13,21–27 A cytotoxicity evaluation was conducted employing a standard MTT assay with A549 cells. The A549 cells were planted in a 96-well plate with a density of about 6000 cells in each well, cultivated for 24 hours, and then further grown for 48 hours after the addition of one of 0, 5, 10, 20, to 50 μM concentrations of probe A or B in fresh culture medium to the cells.…”

Reduced Phosphorene Quantum Dot Incorporated Flexible Bio-Electronic Device for the Detection of Uric Acid in Real Media

“…Additionally, the co-effect of GSH and PMAA causes the Ag NCs to aggregate to form bigger Ag NPs. The linear range between the fluorescent quenching and GSH concentration was 0.01–40 μM, with an LOD of 8 nM …”

“…The linear range between the fluorescent quenching and GSH concentration was 0.01−40 μM, with an LOD of 8 nM. 29 Ma et al, in another work, developed QDs of MnO 2 using a simple one-step ultrasonic method. The QDs, which were prepared with the assistance of cysteine or bovine serum albumin (BSA), were expected to display better fluorescence properties.…”