Silicon corrole functionalized color catcher strips for fluoride ion detection

Abstract

Monitoring fluoride ions in drinking water is essential for human health. The ability of (Hydroxy)[5,10,15-tritolylcorrolato]silicon complexes [SiTTC(OH)] to bind fluoride ions with a significant color change is exploited to develop a simple and low-cost device to detect in situ fluoride ions in aqueous media. SiTTC(OH) was deposited on Color Catcher® (CC) strips, representing the first example of this support functionalized with a neutral receptor insoluble in water. The CC-SiTTC(OH) strip preparation protocol was optimized to obtain the best performances. Binding of F−led to a drastic color change in CC-SiTTC (OH), and colorimetric measurements were performed with an inexpensive instrumental setup similar to photo-assisted technique (PT), obtaining a LOD lower than the legal limit of 1.5 mg/L (≈ 80 µM) allowed by WHO. The value of the colorimetric variation, processed in terms of Hue, is able to measure with great accuracy the F−concentration in water samples.

Keywords

• Optical sensors
• Test strips
• Corrole
• Fluoride ions