Synthesis of Fe-Doped Peroxidase Mimetic Nanozymes from Natural Hemoglobin for Colorimetric Biosensing and In Vitro Anticancer Effects

Abstract

: Despite their efficiency and specificity, the instability of natural enzymes in harsh conditions has inspired researchers to replace them with nanomaterials. In the present study, extracted hemoglobin from blood biowastes was hydrothermally converted to catalytically active carbon nanoparticles (BDNPs). Their application as nanozymes for the colorimetric biosensing of H2O2 and glucose and selective cancer cell-killing ability was demonstrated. Particles that were prepared at 100 °C (BDNP-100) showed the highest peroxidase mimetic activity, with Michaelis–Menten constants (Km) of 11.8 mM and 0.121 mM and maximum reaction rates (Vmax) of 8.56 × 10−8 mol L−1 s−1 and 0.538 × 10−8 mol L−1 s−1, for H2O2 and TMB, respectively. The cascade catalytic reactions, catalyzed by glucose oxidase and BDNP-100, served as the basis for the sensitive and selective colorimetric glucose determination. A linear range of 50–700 µM, a response time of 4 min, a limit of detection (3σ/N) of 40 µM, and a limit of quantification (10σ/N) of 134 µM was achieved. In addition, the reactive oxygen species (ROS)-generating ability of BDNP-100 was employed for evaluating its potential in cancer therapy. Human breast cancer cells (MCF-7), in the forms of monolayer cell cultures and 3D spheroids, were studied by MTT, apoptosis, and ROS assays. The in vitro cellular experiments showed dose-dependent cytotoxicity of BDNP-100 toward MCF-7 cells in the presence of 50 µM of exogenous H2O2. However, no obvious damage was induced to normal cells in the same experimental conditions, verifying the selective cancer cell-killing ability of BDNP-100.

Quantification of Neuronal Cell-Released Hydrogen Peroxide Using 3D Mesoporous Copper-Enriched Prussian Blue Microcubes Nanozymes: A Colorimetric Approach in Real Time and Anticancer Effect

“…Despite their effectiveness and specificity, horseradish peroxidase (HRP) has conventionally been used in H 2 O 2 colorimetric sensors. However, this enzyme’s susceptibility to harsh physicochemical conditions and its substantial cost have posed limitations . To overcome these issues, artificial enzymes, called nanozymes, have emerged.…”

“…Nanozymes offer remarkable advantages in medicinal applications, particularly in the context of therapeutic strategies for cancer cells . Chemodynamic treatment (CDT) is a potential approach for treating cancer that utilizes Fenton-type reactions catalyzed by intercellular H 2 O 2 in nanomaterials with a redox pair (M n + /M n +1 ) to produce • OH that can cause cancer cell apoptosis. , Unlike traditional ROS-mediated therapies, CDT does not require an external energy input or oxygen, which overcomes some of the challenges associated with conventional treatments.…”