Multifunctional nanozymes: for cancer diagnosis, treatment and monitoring

Natural enzymes are often constrained by high production costs, susceptibility to denaturation and inactivation, and low yields, all of which limit their widespread application. As an emerging class of artificial enzymes, nanozymes, which integrate the properties of nanomaterials and enzymes, have attracted increasing attention as promising alternatives. Multifunctional nanozymes, defined as nanomaterials possessing enzyme like catalytic activities, exhibit considerable potential in tumor theranostics due to their high stability, tunable catalytic performance, and favorable biocompatibility. This review systematically summarizes the classification of nanozymes and their applications in tumor diagnosis, therapy, and monitoring. In diagnostics, nanozymes enable highly sensitive in vitro detection of biomarkers such as circulating tumor cells (CTCs), ctDNA, and miRNAs, and facilitate precise tumor localization and real-time monitoring in vivo through multimodal imaging modalities including fluorescence, magnetic resonance, and photoacoustic imaging. In therapeutics, by mimicking the activities of peroxidase (POD), oxidase (OXD), catalase (CAT), and superoxide dismutase (SOD), nanozymes participate in diverse treatment strategies such as cascade catalytic reactions, immunomodulation, photodynamic therapy (PDT) and sonodynamic therapy (SDT), photothermal therapy (PTT), and starvation therapy, as shown in Scheme 1. These approaches effectively modulate the tumor microenvironment (TME), enhance treatment specificity, and reduce side effects. Although significant progress in nanozyme based tumor theranostics, challenges remain, including insufficient catalytic specificity, limited in vivo targeting efficiency, unclear long-term biosafety, and the lack of mature large-scale manufacturing processes. Future efforts should prioritize biomimetic design, material optimization, multimodal synergy, and clinical translation to further advance nanozymes toward a precise, efficient, and safe platform for tumor diagnosis and therapy.