Detection of p53 Protein Based on Mesoporous Pt–Pd Nanoparticles with Enhanced Peroxidase-like Catalysis

We reported a sensitive immunochromatographic test strip based on mesoporous Pt–Pd bimetal nanoparticles (NPs) with greatly enhanced peroxidase-like catalysis for detection of p53 visually and quantitatively. The principle of this assay is relied on the measurements of visual color intensity produced by peroxidase reaction with 3,3′,5,5′-tetramethylbenzidine (TMB) solution. Owing to the strong peroxidase-like activity of Pt–Pd NPs, it exhibited strong visual color in less than 30 s in low concentration range of target analytes. Quantitative measurement of p53 was performed with a hand-held test strip reader, which yields a detection limit of 0.05 ng mL–1 with the linear range of 0.1–10 ng mL–1. Although the feasibility was demonstrated using p53 as a model analyte, this approach could be easily extended for detection of other protein biomarkers.