Towards an autonomous microfluidic sensor for dissolved carbon dioxide determination Pérez de Vargas Sansalvador, Isabel María López Ruiz, Nuria Erenas Rodríguez, Miguel María Capitán Vallvey, Luis Fermín Coleman, Simon Diamond, Dermot Fernández Ramos, María Dolores CO2 sensor Microfluidics Water analysis Autonomous monitoring Carbon dioxide In this work, we present a new system for the determination of dissolved carbon dioxide (from 7.2 ppm to 425.6ppm) in aqueous environments. Microfluidic technology has been incorporated in sensor design to reduce the volume of samples and reagents. Moreover, a detection system has been integrated in the chip, consisting of a white light-emitting diode as a light source and a high-resolution digital colour sensor as the detector, which are able to detect changes in colour produced by the reaction of the sensing chemistry and carbon dioxide in water. The optimised parameters found for the system are: flow rate 0.6 mL·min-1, integration time 30 s and the time for pumping of solutions was 3 min, obtaining a LOD of 7.2 ppm. The CO2 response, reproducibility, precision, and stability of the sensing chemistry have been studied and compared with those obtained using benchtop instrumentation (i.e. a spectrophotometer), obtaining good agreement. 2019-02-13T11:52:00Z 2019-02-13T11:52:00Z 2018-02 info:eu-repo/semantics/article Isabel M. Perez de Vargas Sansalvador, Nuria Lopez Ruiz, M.M. Erenas, Luis Fermin Capitan Vallvey, Simon Coleman, Dermot Diamond, Maria Dolores Fernandez Ramos , Towards an autonomous microfluidic sensor for dissolved carbon dioxide determination Microchemical Journal Volume 139, June 2018, Pages 216-221 http://hdl.handle.net/10481/54727 https://doi.org/10.1016/j.microc.2018.02.018 eng info:eu-repo/semantics/openAccess