Aptasensor Based on Hierarchical Core–Shell Nanocomposites of Zirconium Hexacyanoferrate Nanoparticles and Mesoporous mFe(3)O(4)@mC: Electrochemical Quantitation of Epithelial Tumor Marker Mucin-1

[Image: see text] A novel nanostructured hierarchical core–shell nanocomposite of zirconium hexacyanoferrate (ZrHCF) and a mesoporous nanomaterial composed of Fe(3)O(4) and carbon nanospheres (denoted as ZrHCF@mFe(3)O(4)@mC) was prepared and used as a novel platform for an aptasensor to detect the epithelial tumor marker mucin-1 (MUC1) sensitively and selectively. The prepared ZrHCF@mFe(3)O(4)@mC nanocomposite exhibited good chemical functionality, water stability, and high specific surface area. Therefore, large amounts of aptamer molecules resulted in high sensitivity of the developed electrochemical aptasensor toward traces of MUC1. The constructed sensor also showed a good linear relationship with the logarithm of MUC1 concentration in the broad range of 0.01 ng·mL(–1) to 1.0 μg·mL(–1), with a low detection limit of 0.90 pg·mL(–1). The fabricated ZrHCF@mFe(3)O(4)@mC-based aptasensor exhibited not only high selectivity because of the formation of aptamer–MUC1 complex but also good stability, acceptable reproducibility, and applicability. The proposed novel strategy based on a newly prepared hierarchical core–shell nanocomposite demonstrated outstanding biosensing performance and presents potential applications in biomedical fields.