In this communication we present the PIIISA project. The main objective of this project is to show to high school students what research is. Students have the opportunity to participate in research projects in different groups of the University of Granada in order to know what is scientific inquiry and, eventually, if they would like to be a researcher in the future. The title of the project carried out in our research group was: Do you know you could detect different gases by combining chemistry and a mobile phone? In summary, the students preparing two sensing membranes, for CO2 and O2 determination in modified atmosphere packed food, in order to know the freshness of food products.

The project consisted in four sessions; one of them a theoretical one (25%), two sessions working in the laboratory (50%) and the last one of data treatment and results analysis (25%).

During the theoretical session we taught the high school students about new topics of chemistry, not included in their syllabus such as gases theory, analytical chemistry, spectrophotometry, colorimetry and chemical sensors trying to adapt all the new concepts to their previous knowledge.

Session 2 and 3. In the laboratory session the students learnt to prepare solutions and cocktails for membrane preparation by spin-coating technique, as well as gaseous standard mixtures for membrane characterization using mass flow controllers and to perform calibration of prepared sensor and measure unknown gaseous mixtures.

Session 4. The analysis of data obtained in the laboratory was performed using a spreadsheet software and conclusions from them were obtained by the students, as well as the preparation of a poster in order to show their work to other students that also take part in the PIIISA project.

In the end, students were asked to complete a survey in order to know their degree of involvement in the project, as well as to know their weaknesses and strengths and to evaluate the work done and their potential capacities as future researchers.

This work was funded by Spanish Ministerio de Economía y Competitividad under Projects CTQ2013-44545-R, CTQ2016-78754-C2-1-R and FCT-16-10826. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 706303 (Multisens).