Disposable electrochemical flow cell with paper-based electrode assemble

High performance liquid chromatography-electrochemical detector (HPLC-EC) is employed as a reliable device for the detection of catecholamines in blood or urine samples without any time-consuming extraction procedure. However, there is a need for the construction of cheap and easy-to-operate electrode assemble systems embedded in HPLC-EC. In this study, we present a disposable and low-cost paper-based electrode (PBE) assemble utilizing a nitrocellulose membrane, which serves support material in flow-cell device for HPLC-EC. A custom-built flow cell was inventively designed as specific to the prepared PBEs via stereolithography 3D printing. To gain the electrochemical signal enhancement, the working electrode was modified with gold nanoparticles and carboxylated-multi-walled carbon nanotubes (MWCNTs). Here, we focused on the construction of the paper-based electrode assemble and characterization of the flow cell device performance. To demonstrate the functionality of the flow cell device, we analyzed common catecholamines from spiked biological fluids using the optimized experimental parameters. Amperometric detection of the catecholamines was carried out at the potential of + 0.5 V and linear range was found to be 0.5-20.0 mu g/mL, with a limit of detection in the range of 4.0-15.0 ng/mL. The obtained results confirmed our disposable paper-based electrode assemble to be promising for the construction of an electrochemical platform for reliable and fast detection of electroactive species.