Abstract: A method for measuring the concentration of a compound for analysis in an original sample includes placing a first compound in a first electrochemical transducer, measuring a first concentration by applying a potential in the electrochemical transducer, mixing the first compound with a second compound, placing the modified sample in a second electrochemical transducer, and measuring a second concentration by applying a potential in the electrochemical transducer. The first or the second compound is a part of the original sample. Lastly, an operation is performed between the first and the second concentration to obtain the concentration of the compound for analysis in the original sample.

Abstract: A microfluidics valve comprises at least two substrates (1) between which there is at least a microchannel (5). It additionally comprises at least a barrier (4) of a meltable material, placed in the microchannel. The valve further comprises at least an optical heater (6) placed in correspondence with the barrier (4) and at least a section of one of the substrates (1), in correspondence with the optical heater (6), is transparent. The optical heater is a colored line that, when is illuminated with a light source, is heated and releases the heat to the barrier (4) thus melting the part of it that is closer to the line.