Flexible platinum electrodes as electrochemical sensor and immunosensor for Parkinson's disease biomarkers

In this study, platinum electrodes were fabricated on the bio-based poly(ethylene terephthalate) (Bio-PET) substrates for the development of flexible electrochemical sensors for the detection of Parkinson's disease biomarkers. Dopamine was detected by voltammetric measurements, displaying a 3.5 × 10^-5 mol L^-1 to 8.0 × 10^-4 mol L^-1 linear range with a limit of detection of 5.1 × 10^-6 mol L^-1. Parkinson's disease protein 7 (PARK7/DJ-1) was successfully detected by electrochemical impedance spectroscopy after electrode functionalization with specific anti-PARK7/DJ-1 antibodies. In this case, analytical curves presented a linear behavior from 40 ng mL^-1 to 150 ng mL^-1 of PARK7/DJ-1 with a limit of detection of 7.5 ng mL^-1. Besides, the electrodes did not suffer any change in the electrochemical response after manual tests of mechanical tension. The proposed sensor and immunosensor were applied for the determination of Parkinson's disease biomarkers concentrations found in the human body, being adequate as an alternative method to diagnose this disease.