Sensitive and selective detection of Cu2+ and Pb2+ ions using Field Effect Transistor (FET) based on L-Cysteine anchored PEDOT:PSS/rGO composite

An architecture of FET sensor for the detection of heavy metal ions. [Display omitted] •The Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/reduced graphene oxide/L-Cysteine (PEDOT:PSS/rGO/LC) synthesized successfully.•Field-Effect Transistor (FET) sensor for the sensitive and selective detection of copper and lead (Cu2+ and Pb2+) ions are discussed.•Sensor device responded within 2–3 s after incubation of the Cu2+ and Pb2+ ions solution over PEDOT:PSS/rGO/LC Channel. Herein, Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/reduced graphene oxide (rGO) (PEDOT:PSS/rGO) composite was prepared and further functionalized with L-Cysteine (LC) to manifest sensitive and selective detection of copper (Cu2+) and lead (Pb2+) ions using Field Effect Transistor (FET) in the concentration range of 1–60 µg/L. The sensor (PEDOT:PSS/rGO/L-Cysteine) exhibits low-voltage operations, highly sensitive and selective towards target metal ions (Cu2+ and Pb2+). The lower detection limits for Cu2+ and Pb2+ were found to be 0.33 µg/L and 2.36 µg/L, which is well below the World Health Organization WHO recommendations (2 mg/L (2 ppm) for Cu2+ ions and 10 µg/L (10 ppb) for Pb2+ ions.