Frontiers in laccase nanozymes-enabled colorimetric sensing: A review

In recent years, nanozyme-based analytics have become popular. Among these, laccase nanozyme-based colorimetric sensors have emerged as simple and rapid colorimetric detection methods for various analytes, effectively addressing natural enzymes' stability and high-cost limitations. Laccase nanozymes are nanomaterials that exhibit inherent laccase enzyme-like activity. They can oxidize phenolic compounds to generate a coloured product, independently or with a chromogenic agent. This chromogenic reaction provides the basis for developing simple and robust colorimetric assays for various analytes, enabling rapid and point-of-need analytical decision-making in food safety, clinical diagnostics, and environmental monitoring. This review article provides a concise overview of laccase nanozymes, including their classification and catalytic mechanisms. The article mainly discusses colorimetric and dual-mode detection methods and outlines various strategies to enhance the colorimetric sensing performance of laccase nanozymes. Additionally, the article highlights future research directions that could further improve laccase nanozyme-enabled colorimetric sensing. We hope this work will enhance the field's understanding and help future researchers identify gaps in developing simple, low-cost colorimetric sensors.