An electrochemical aptasensor for hydrocortisone detection using V-PMOF-derived porous nanomaterials from V₂CT_x...

An electrochemical aptasensor for hydrocortisone (HC) detection was developed using a vanadium-based porphyrinic metal-organic framework (V-PMOF) materials synthesized from vanadium-based MXene (V₂CTₓ) and tetrakis (4-carboxyphenyl) porphyrin (TCPP), followed by thermal treatment at 800 °C to obtain V-PMOF_800°C. The resulting V-PMOF_800°C retained a nanoflower-like porous structure, enhancing electron transport, structural integrity, and electroactive site accessibility. Gold nanoparticles (Au NPs) were electrodeposited onto the V-PMOF_800°C-modified electrode to improve conductivity and enable thiolated DNA aptamer (DNA_apt) immobilization via Au-S bonding. Electrochemical measurements, particularly differential pulse voltammetry (DPV), were employed to evaluate the performance of the aptasensor, which exhibited a wide linear concentration range (0.05 nM-5 μM) and a low detection limit (LOD) of 10 pM. This work introduces a promising strategy for constructing MXene or MOF-based aptasensors with high sensitivity, selectivity, and stability for practical hormone monitoring applications.