Nanozyme-based analytical platforms in pharmaceutical and clinical sample analysis

Enzymatic diagnostics are based on naturally occurring enzymes, but they have limitations such as their inherent instability and high production costs, and they need to be stored under stringent conditions to maintain enzyme activity. Nanozymes are engineered nanomaterials with inbuilt enzyme-like catalytic activity that have become powerful and cost-effective alternatives that can withstand harsh environmental conditions. This systematic review critically reviews the recent status of nanozyme-based analytical platforms and summarizes the catalytic processes at atomic level of the most important classes of nanozymes such as metal oxides, noble metals, carbon-based materials and Metal-Organic Frameworks (MOFs). Beyond descriptive summaries, we critically evaluate how these materials have been translated to pharmaceutical quality control and clinical diagnostics, and what the actual impact and usefulness is of the quantification of the active ingredient and the identification of impurities in complex matrices. Moreover, this review highlights the development of nanozymes coupled with Point-of-Care (POC) devices such as lateral flow assays and microfluidic paper-based analytical devices (μPADs) for the instrument-free measurement of biomarker. Finally, we discuss the important translational challenges, primarily the substrate selectivity and regulatory compliance, and predict the rational development of highly efficient single-atom nanozymes.