This study reports a new artificial nanozyme based on ultra-small Pt nanoparticles (Pt NPs) grown on nanoscale metalloporphyrin metal organic frameworks (P-MOF(Fe)) (termed as Pt@P-MOF(Fe)) as biomimetic catalysts and redox mediator to detect the telomerase activity. In this system, the P-MOF(Fe) were used as nanocarrier and signal media. The DNA functionalized Pt@P-MOF(Fe) was as signal probe and exhibited enhanced electrochemical signal in the presence of H2O2, owing to the synergistic effect between P-MOF(Fe) and Pt NPs. Upon the addition cell extract, the telomerase primer could extend and then hybridize with assistant DNA2 in the triple-helix, leading to the structure of triple-helix changes and release the hairpin DNA to hybridize with the capture DNA on the surface of Pt@P-MOF(Fe), resulting in the electrochemical signal readout of H2O2 reduction. With the aid of recycling amplification of Exonuclease III, the telomeres sensor exhibited the detection down to 20 Hela cell mL-1. This work supplies a new avenue to design artificial enzyme catalysts and serves as an ideal platform to use metalloporphyrin metal organic frameworks as signal media for detection of analytes.
Keywords: Artificial nanozymes; Electrochemical sensor; Metal-organic framework; Signal amplification; Telomeres.
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