An accurate and easy-to-use Q3 system for on-chip quantitative real-time Polymerase Chain Reaction (qPCR) is hereby demonstrated, and described in detail. The qPCR reactions take place inside a single-use Lab-on-a-Chip with multiple wells, each with 5 to 15 µL capacity. The same chip hosts a printed metal heater coupled with a calibrated sensor, for rapid and accurate temperature control inside the reaction mixture. The rest of the system is non-disposable and encased in a 7 × 14 × 8.5 (height) cm plastic shell weighing 300 g. Included in the non-disposable part is a fluorescence read-out system featuring up to four channels and a self-contained control and data storage system, interfacing with an external user-friendly software suite. Hereby, we illustrate the engineering details of the Q3 system and benchmark it with seamlessly ported testing protocols, showing that Q3 equals the performance of standard commercial systems. Overall, to the best of our knowledge, this is one of the most mature general-purpose systems for on-chip qPCR currently available.

This work reports the design and validation of a reusable platinum (Pt) electrode platform (ST-E) for green electrochemical analysis. The device integrates Pt working and counter electrodes with an external Ag/AgCl reference and is engineered for repeated regeneration and refunctionalization. Surface renewal by alumina polishing followed by electrochemical activation in 0.5 M H₂SO₄ restores a clean, reproducible Pt surface, as confirmed by diffusion-controlled, reversible ferricyanide voltammetry over 5–150 mV s⁻¹ with near-Nernstian peak separation and i_pa/ipc ≈ 1. Platform versatility is demonstrated in two applications. First, ST-E is functionalized with PFOA-selective molecularly imprinted nanoparticles on an APTES layer, enabling trace determination of perfluorooctanoic acid (1–5 pg mL⁻¹), with a detection limit of 0.50 pg mL⁻¹ and sensitivity of 3.16 μA (pg mL⁻¹)⁻¹. Responses correlate with an equivalently modified commercial screen-printed electrode (r = 0.990, p < 0.005), with Bland–Altman analysis confirming concordance. Second, after regeneration, electropolymerization of o-phenylenediamine yields an insulating poly(o-phenylenediamine) film that attenuates redox currents and increases ΔE_p, illustrating compatibility with diverse surface chemistries. Green metrics (AGREE, AGREEprep ≈ 0.80; BAGI = 75.0) highlight reduced waste and solvent use versus single-use transducers and compatibility with portable potentiostats, supporting circular electrochemical sensing.