Nitric oxide (NO) and hydrogen peroxide (H₂O₂) play pivotal roles in cellular signaling, immune defense, and redox homeostasis. Their dysregulation is implicated in inflammation, neurodegenerative diseases, cancer progression, and cardiovascular dysfunction. The ability to monitor these molecules in real time, especially in complex biological environments, is essential for both fundamental research and clinical diagnostics. However, conventional detection methods face challenges such as low sensitivity, poor temporal resolution, and interference from endogenous species. Electrochemical sensing has emerged as a powerful tool due to its rapid response, high sensitivity, and potential for miniaturization. Yet, reliance on enzymes limits practical application due to instability and cost.
To address these issues, this study introduces a nano-metalloporphyrinic metal-organic framework (NporMOF(Fe)) as a multifunctional electrocatalytic platform capable of detecting NO and H₂O₂ without enzymatic mediation. The framework is synthesized from zirconium ions and iron(III)-meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP(Fe)), resulting in a nanoscale structure with uniform dimensions (~110 nm). This architecture provides a high surface area, abundant exposed Fe active sites, and excellent chemical stability—key attributes for biomimetic catalysis. The NporMOF(Fe) mimics the activity of multiple enzymes: it exhibits peroxidase-like behavior toward H₂O₂ reduction and nitric oxide reductase-like activity toward NO conversion.
Electrochemical characterization reveals that the NporMOF(Fe)/GCE electrode generates a well-defined cathodic peak at -0.55 V in acidic phosphate buffer (pH 2.5), corresponding to the electrocatalytic reduction of NO produced from NaNO₂ via disproportionation. The sensor displays a broad linear range of 5–200 µM and a detection limit of just 1.UHRF1 Antibody MedChemExpress 3 µM, surpassing many existing MOF-based sensors.729-46-4 Biological Activity The kinetics follow first-order dependence on NO₂⁻ concentration, indicating efficient catalytic turnover.PMID:35263637 Notably, the electrode maintains high selectivity even when challenged with physiologically relevant interferents—including ascorbic acid, dopamine, uric acid, glutathione, and various metal ions—demonstrating minimal cross-reactivity.
For H₂O₂ detection, the same electrode shows a distinct reduction peak at -0.3 V in neutral buffer (pH 7.4). The current response increases linearly with H₂O₂ concentration over the range of 3–100 µM, with a detection limit of 1.1 µM. The performance is further validated by real-time monitoring of H₂O₂ released from stimulated HeLa cells upon fMLP addition. The signal correlates directly with cell density, enabling detection down to 500 cells/mL—a level competitive with state-of-the-art biosensors. The sensor also demonstrates excellent reproducibility (RSD < 4.3%) and long-term stability (>91% signal retention after 10 days), attributable to the robustness of the NporMOF(Fe) structure.
This work establishes NporMOF(Fe) as a highly effective, stable, and selective nonenzymatic platform for real-time electrochemical detection of key bioactive molecules. Its multienzyme functionality, nanoscale design, and mediator-free operation make it ideal for next-generation biosensors. Future efforts will focus on integrating this material into wearable or implantable devices for continuous in vivo monitoring, paving the way for early disease diagnosis and personalized medicine.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com