Carboxylated Cellulose as a Soft Template Combined with PEDOT Derivatives in [BMIM]Cl: A Competent Biosensor for Detection of Guanine and Uric Acid in the Blood

In this paper, carboxylated cellulose (CLC) dissolved in [BMIM]Cl as a soft template combined with the functional group (−NH2, −SH)-grafted poly(3,4-ethylene dioxythiophene) (PEDOT) derivatives was synthesized by an in situ polymerization method. Structural analysis revealed that CLC increased the degree of conjugation of the polymers in the composites and also led to the formation of the fibrous and sheet structure of the composite. The results of the electrochemical performance measurements revealed that the electrode modified by PEDOT-MeNH2/CLC and PEDOT-MeSH/CLC had detection limits (S/N = 3) of 0.38(0.1–380 μM) and 0.042(0.02–520 μM) for the detection of guanine (G), while for the detection of uric acid (UA), the corresponding detection limits (S/N = 3) were 0.255(5–400 μM) and 0.085(0.4–650 μM). The PEDOT-MeSH/CLC-based electrochemical sensor also possessed a wide linear response with the detection limits of 0.077(0.6–620 μM) and 0.144(0.2–460 μM) for the simultaneous detection of UA and G, respectively.