A colorimetric sensor based on aptamer-functionalized nanozyme probes was successfully developed for the sensitive and specific detection of influenza A (H1N1) virus. In this study, trimetallic nickel-palladium-gold hollow nanozymes (NPA) with excellent peroxidase (POD)-like activity were used as catalytic probes. Compared to the horseradish peroxidase (HRP), the NPA nanozyme exhibits superior peroxidase-like activity, demonstrating a lower Michaelis constant (Km) and a higher maximum reaction rate (Vmax) for the substrates TMB and H2O2, indicating enhanced substrate affinity. Via the gold-sulfur bond interaction, thiol-modified aptamers that could specifically recognize H1N1 hemagglutinin (HA) were immobilized on the nanozyme surface, enabling accurate HA recognition under two detection methods: (1) For the colorimetric biosensor, the binding of HA to the aptamer formed an interfacial steric hindrance layer on the nanozyme surface, which inhibited the catalytic reaction, leading to a significant decrease in absorbance; (2) In the modified ELISA, the "antibody-HA-aptamer" sandwich structure enriched nanozymes at the detection interface, and a color signal enhancement correlated with HA concentration was observed after adding the chromogenic substrate. Experimental results showed that the dual-mode method achieved linear detection ranges of 2–250 ng·mL-1 and 2–62.5 ng·mL-1 for HA protein, with limits of detection (LODs) as low as 1.5 ng·mL-1 and 1.2 ng·mL-1, respectively. This method also exhibited good specificity against other influenza virus subtypes (e.g., H5N1) and was successfully applied to the detection of inactivated H1N1 virus in serum samples. Furthermore, by integrating a smartphone-based colorimetric analysis system, demonstrating its potential for rapid and on-site detection of the H1N1 virus. This work provides a new insight for the development of target-specific nanozyme sensors.