Engineering a Single Amino Acid Bionanozyme for Ultrasensitive Detection of Biomarkers: A WHO-REASSURE- Aligned Approach

Abstract

The development of advanced biosensing materials that adhere to the WHO-REASSURE standards is crucial in resource-constrained environments. Conventional peroxidase (POD) enzymes, essential for sensitive and selective colorimetric assays, encounter challenges such as high production costs, operational instability, complex fabrication processes, and non-reusability. In response to these challenges, an affordable, easily synthesized, and environmentally friendly single amino acid bionanozyme (F-Cu) have been engineered. This bionanozyme harnesses phenylalanine (F) and redox-active Cu2⁺ ions to create 2D hierarchical van der Waals crystals. The F-Cu nanosheets exhibit rapid and real-time POD-mimicking catalytic activity, efficiently reducing hydrogen peroxide (H₂O₂), and demonstrating robustness under extreme pH, long-term storage, and elevated temperatures. Additionally, the F-Cu bionanozyme facilitates user-friendly, sensitive, and specific equipment-free visual detection of biomarkers, including Hydrogen peroxide (H₂O₂), dopamine (DA), and nitrite ions (NO2−), with detection limits as low as 5, 1.5, and 4 µm, respectively. These results underscore the alignment of the F-Cu bionanozyme with the WHO-REASSURE standards and its potential to address the future requirements of point-of-care diagnostics, biotechnology, food safety, and analytical chemistry applications. © 2025 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH.