Patterned threads as solid-state reagent storage and delivery medium for automated periodic colorimetric monitoring of the environment

Environmental monitoring requires periodic measurement of parameters such as pH, heavy metals, nitrates and phosphates in field settings, autonomously. Microfluidic devices have been considered for environmental sensing due to its inherent advantages of lower volume, faster sensing and low-cost fabrication. Various sensing methods including colorimetric, fluorescence and electrochemistry have been studied. Among them, colorimetric sensing is …