An ecofriendly AuNPs/semi-amorphous MOF-based sensor for in-situ testosterone monitoring for clinical diagnosis and doping control

A novel ecofriendly electrochemical sensor for in-situ detection of testosterone based on gold nanoparticles (AuNPs) and a semi-amorphous metal organic framework (MOF) has been developed for clinical diagnosis and doping control. For this purpose, MIL-100(Fe) has been synthetized according to a green path with crystallization times tuned in the range 2–24 h. The sensor platform was constructed via drop-casting MOF and AuNPs onto a graphene (GPH) screen-printed electrode (SPE) surface. The surface structure and morphology and the electrochemical properties of unmodified and modified electrodes were investigated by (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), demonstrating the enhanced electrochemical response of the platform modified with MOF obtained with the shorter crystallization time of 2 h (MOF2h) and AuNPs, compared to unmodified electrode. The AuNPs/MOF2h/GPH/SPE based sensor was responsive to nanomolar concentrations of testosterone, showing a wide linear range from 1 to 50 nM and a detection limit (LOD) of 0.5 nM, which correlates to the serum concentration values of healthy males. The combination of these results with the excellent performance maintained by the proposed sensor when interfaced with a miniaturized potentiostat (Sensit-Smart) directly connected to a smartphone, highlights the potential of this device towards in-situ electrochemical testosterone sensing, in particular for medical diagnosis and for doping control.