Organic conjugated polymers (conducting polymers) have emerged as potentialcandidates for electrochemical sensors. Due to their straightforward preparation methods,unique properties, and stability in air, conducting polymers have been applied to energystorage, electrochemical devices, memory devices, chemical sensors, and electrocatalysts.Conducting polymers are also known to be compatible with biological molecules in aneutral aqueous solution. Thus, these are extensively used in the fabrication of accurate,fast, and inexpensive devices, such as biosensors and chemical sensors in the medicaldiagnostic laboratories. Conducting polymer-based electrochemical sensors and biosensorsplay an important role in the improvement of public health and environment because rapiddetection, high sensitivity, small size, and specificity are achievable for environmentalmonitoring and clinical diagnostics. In this review, we summarized the recent advances inconducting polymer-based electrochemical sensors, which covers chemical sensors(potentiometric, voltammetric, amperometric) and biosensors (enzyme based biosensors,immunosensors, DNA sensors).

A disposable glucose biosensor has been fabricated on the surface of a cost-effective pencil graphite electrode (PGE) by an electrochemical method, using glucose oxidase (GOx) and reduced graphene oxide (rGO). Electrochemical pre-treatment of the PGE enables the adsorption of the rGO–GOx biocomposite. The biocomposites of GOx and rGO were simply prepared by the electrochemical potential cycling method. Efficient immobilization of rGO–GOx is confirmed by field emission scanning electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry measurements. The rGO nanosheets enhance direct electron transfer (DET) between GOx and the electrode surface. Determination of glucose indirectly by O₂ reduction was achieved, which showed high sensitivity, selectivity, reproducibility and stability without a redox mediator. The sensor exhibits a linear current response for a wide range of glucose concentrations between 1.0 × 10⁻⁵ and 1.0 × 10⁻³ M (R = 0.998), and a dynamic range up to 10.0 × 10⁻³ M with a detection limit of 5.8 μM. The rGO–GOx biosensor showed an excellent anti-interference ability against electroactive species and proved to be useful for the determination of glucose in human serum samples.