Simple and Economical Analytical Voltammetry in 15 μL Volumes: Paracetamol Voltammetry in Blood Serum as a Working Example

Reported is a three-electrode mini-cell for voltammetry in 15 μL solutions. The key device component is a rolled platinum foil of an inverted omega-shaped cross section, which functions as both the electrolyte container and the counter-electrode. The analytical assembly was completed with properly sized working and reference electrodes in the two terminals of the quasi-tubular Pt trough. Its applicability in electrochemical assays of 15 μL solutions was verified by redox mediator voltammetry at graphite and noble metal sensors and by trace lead stripping voltammetry. Real sample analysis was adequate for drug detection in a volunteer’s blood, drawn before and 1 or 4 h after ingestion of paracetamol. In line with its known pharmacokinetics, lack of drug as well as drug presence and clearance were proven correctly in the three samples. The mini-cell here is easy to assemble and operate, indefinitely reusable, and offers valuable economy in chemical usage and minimal waste. This is primarily a versatile devi...