Development of a microfluidic paper-based sensor for aluminium assessment in water for domestic consumption

Aluminium is one of the most abundant metal ions in soil and its leaching into groundwater is an expected consequence. Monitoring the presence of Al3+ in water sources used for domestic consumption water is crucial, considering its relationship with some neurogenetic disorders, namely Alzheimer’s and Parkinson’s diseases, autism, and multiple sclerosis. In this work, the design and development of a novel microfluidic paper-based analytical device (µPAD) specifically designed for the determination of aluminium in water sources for domestic consumption is presented (Figure 1). The proposed µPAD methodology is based on the colorimetric reaction between Al3+ and Chrome Azurol S (CAS), resulting in the formation of a blue complex. Several physical and chemical parameters aZecting the formation of the colour complex were studied to attain the best performance of the paper sensor. These parameters included the µPAD filter paper layers, in terms of number, type and porosity, reagent and buZer concentration, and sample volume. The developed paper device should enable aluminium quantification within in the analytical range of 50 – 1000 µg/L.