Upcycling recycled PET into a conductive electrode for a molecularly imprinted polymer based electrochemical sensor for 17β-estradiol detection.
Tahir Muhammad Faran MF, Yimyai Tiwa T, D'Haen Jan J, Thoelen Ronald R et al.
The upcycling of plastic waste into advanced materials has emerged as a promising strategy across various technologies, including the development of next-generation sensors. This sustainable approach promotes green technological development. In this work, we transformed recycled polyethylene terephthalate (rPET) into a functional conductive electrode substrate for a molecularly imprinted polymer (MIP) based electrochemical sensor for the detection of 17β-estradiol (E2). The latter also serves as a relevant model compound as a pollutant to study the sensor's applicability in complex matrices. The MIP-based sensor was fabricated by the electropolymerization of an o-phenylenediamine (o-PD) monomer in the presence of E2 template molecules and gold(iii) chloride trihydrate onto gold-coated rPET substrates. The physical properties of MIP films were characterized by scanning electron microscopy (SEM), atomic force microscopy, contact angle measurement, cyclic voltammetry, and electrochemical impedance spectroscopy. The binding of E2 molecules to the MIP surface hindered electron transfer of the redox probes, resulting in a concentration-dependent suppression of the electrochemical current measured by square wave voltammetry. The sensor showed high affinity for E2 molecules with a dissociation constant (K d) of 11.2 nM over a linear detection range of E2 concentrations (0.5-500 nM), and a limit of detection (LOD) of 0.18 and 0.41 nM in PBS and in wastewater samples without any complex pretreatment steps, respectively. This developed MIP-based sensor demonstrated the potential of alternative sensors for real-world environmental monitoring of trace endocrine disruptors, while successfully converting rPET into valuable technological products offers a practical roadmap to accelerate the development of sustainable and circular electronics.