Studying the preparation, electrochemical performance testing, comparison and application of a cost-effective...

-A cost-effective flexible graphene working electrode (FGWE) was fabricated using overhead projector transparent film (OPTF) and a screen-printing technique. The surface morphology and electrochemical behavior of the electrode were characterized by scanning electron microscopy and cyclic voltammetry. The electrode presented a very thin layer of conductive ink (16.0 ± 0.7 µm) on a large effective surface area (0.301 ± 0.001 cm^-2). The anodic peak current density (j_pa) of acetaminophen (ACT) in FGWE was 5.2, 3.7, 3.5 and 6.0 times greater than the j_pa of glassy carbon electrode (GCE), flexible carbon working electrode (FCWE), SPE1, and SPE2, respectively. The electrochemical performance of FGWE toward ACT was evaluated by differential pulse voltammetry. Under optimized condition, ACT was quantified in a range of  4-100 µM, with good sensitivity, good accuracy (recovery = 82.3 ± 0.4 to 106 ± 3%), and excellent precision. FGWE was applied to determine ACT in commercial pharmaceutical formulations. The results of the study are in good agreement with those obtained by the standard spectrophotometric method. These results indicate that disposable FGWE is particularly useful for the detection of ACT, and its performance may serve as a platform for cost-effective flexible electrochemical sensors.