A low-cost and miniaturized electrochemical cell for low-sample analyses

Abstract Most of the conventional electrochemical cells require a minimum sample volume of 2-5 mL for the analyses. However most of the times, availability of biological sample in this much quantity is challenging and may be the reason for misreading. Besides, a lower volume cell is always preferred for analyzing rare or expensive materials. Thus, development of a miniaturized electrochemical cell setup (MECS) with a lower volume capacity at an affordable cost is a paramount of interest. In this present work, a home-made MECS is developed using a disposable graduated microcentrifuge tube vial as a low-volume (150 μL) holding electrochemical cell and 0.7 mm HB-pencil graphite electrode (PGE), Ag wire and PGE as working, reference and counter electrode respectively. These three electrodes are fused into the disposable graduated microcentrifuge tube vial. In our preliminary investigations, kinetic parameters and electro-catalytic response of uric acid (UA) on working electrode (PGE* = predanodized PGE) was demonstrated as a model system for the application of this newly developed MECS. Furthermore, the developed electroanalytical approach was validated by testing the concentration of UA in non-invasive bio-samples (urine and saliva) with an electrode recovery value of ∼100%.