Synthesis of poly (3,4-ethylenedioxythiophene)/sulfonated cellulose composites in different systems for the electrochemical sensing of paracetamol

In this paper, composites of poly (3,4-ethylenedioxythiophene) (PEDOT) and sulfonated cellulose (SC) were prepared by oxidative polymerization both in CHCl3 and H2O using different SC contents. The structures of composites (PEDOT/SC) were characterized by Ultraviolet-Visible absorption spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Electrochemical sensing using a PEDOT/SC-modified electrode was performed by the differential pulse voltammetry method. The results indicate that SC acted as a soft template for the formation of fibrous composites. Doping PEDOT with SC affected the conjugation degree and crystallinity of the resulting composites. The results showed that the PEDOT/SC composites obtained in H2O exhibited a higher electrochemical response than those produced in CHCl3. The composites obtained using 5 mg/mL SC in both reaction media had the best electrochemical performance. The electrochemical analysis showed that the limit of detection (LOD) for paracetamol was 0.258 mu M and 0.0742 mu M, with linear ranges of 0.02-4000 mu M and 0.08-1580 mu M for composites obtained using 5 mg/mL SC in H2O and CHCl3, respectively.