Abstract

Accurate and sensitive detection of testosterone is essential for monitoring hormonal imbalances and related health conditions. However, existing electrochemical sensors often face challenges in sensitivity, stability, and selectivity. To address these limitations, we developed an aptasensor integrating a Ti3C2Tx MXene-Fe2O3 hybrid nanomaterial for enhanced electrode functionalization and signal transduction. The detection strategy relies on an aptamer and two complementary DNA sequences: in the presence of testosterone, aptamer-target binding prevents hybridization with complementary DNA2, generating a distinct electrochemical response. The aptasensor exhibited a wide linear detection range (0.4-50 ng/mL) and an ultralow detection limit (1.53 pg/mL), demonstrating high selectivity against structurally similar hormones and excellent reproducibility (RSD <5%). Application in water samples yielded recovery rates between 102% and 105%, confirming its practical applicability. This study represents the first use of MXene-Fe2O3 for aptamer immobilization, showcasing its potential for highly stable and sensitive electrochemical biosensing. © 2025 American Chemical Society.