A low cost, versatile and chromatographic device for microfluidic amperometric analyses

•Fully portatile amperometric microfluidic device.•Detection of different molecules with good performance.•Versatile configuration for different application.•An alternative to the current commercial devices for clinical analysis. Microfluidic devices provide an interesting alternative to analytical tests, allowing the reduction in the use of mobile phases, solutions and generation of chemical residues, cost of analysis and simplification of operations. However, there is a problem often not addressed: while inexpensive, the electrochemical microfluidic systems require a commercial potentiostat, making it difficult and expensive their use outside of the laboratory. Here, we describe a cheap (approximately 40 dollars) Arduino-based miniaturized electronic system (with data transmission by USB connection to computer or via Bluetooth to smartphone) integrated with a 3D-printed platform and microfluidic thread-based electroanalytical device to support three different electrodes: graphite electrodes for the determination of uric acid (UA); carbon-printed electrode to quantify hydrochlorothiazide (HCZ); and gold electrodes sputtered into the microfluidic channel for the chromatographic separation and electrochemical determination of ascorbic acid (AA) and epinephrine (EP). A comparison of electrochemical signals obtained using a commercial potentiostat and our system yielded similar results: differences between peak signals were no more than 6.1%. Using our proposed system, a linear range of 5.0–1000.0 μM for UA, 5.0–750.0 μM for HCZ and 100.0–2500.0 μM for both AA and EP was obtained, in addition to a detection limit (LOD) of 1.1 μM for UA, 1.1 μM for HCZ, 6.8 μM for AA and 5.3 μM for EP. Thus, the proposed system was successfully applied in three different situations and showed good analytical performance, similar with the commercial potentiostat but at a much lower cost, fully portable and autonomous.