Aptamer-enhanced organic electrochemical transistors for ultra-sensitive dopamine detection

In this study, we present the development of an ultrasensitive dopamine (DA) aptasensor based on organic electrochemical transistors (OECTs). The aptasensor utilizes a highly efficient DA aptamer immobilized on the surface of a gold gate electrode in the OECT. The functionalization of the aptamer was confirmed through fluorescence intensity measurements and transfer characteristics of the OECT device. Real-time detection of DA was achieved, and the sensor exhibited a linear response in the concentration range of 10 fM to 10 nM, with a detection limit of 10 fM. The aptasensor's working mechanism was elucidated, involving mutual binding between DA and the aptamer that leads to a shift in the transfer characteristics. Our aptasensor shows great promise for sensitive and rapid detection of DA, which is crucial in diagnosing neurological disorders such as Parkinson's and Alzheimer's diseases. The combination of OECTs and aptamer-based recognition elements offers a cost-effective and efficient platform for detecting biomolecules like DA in various clinical applications.