L-Cysteine peptide-functionalized PEDOT-PSS/rGO nanocomposite for selective electrochemical detection of lead Pb(II) ions

Herein, a nanocomposite of Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)/reduced graphene oxide (PEDOT:PSS/rGO) has been synthesized and modified with L-Cysteine (CySH) peptide in order to reveal the selective and sensitive determination of lead Pb(II) ions using electrochemical modality in the range of concentration 1–70 ppb. The PEDOT-PSS/rGO/CySH nanocomposite was characterized with X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), and electrochemical characterizations. Further, the electrochemical sensor was designed on glassy carbon electrode as PEDOT-PSS/rGO/CySH@GCE as an electroactive material which exhibited highly selective and sensitive sensing response for Pb(II) ions sensing. The limit of detection for Pb(II) was found to be 0.09 ppb, which is significantly better than the maximum Pb contamination limit in potable water (48 nM (10 parts per billion) advised by World Health Organization (WHO) and earlier reported studies as well.