Engineering of Portable Smartphone Integrated with Liposome-Encapsulated Curcumin for Onsite Visual Ratiometric Fluorescence Imaging of Hypochlorite

Precisely onsite monitoring of hypochlorite (ClO-) is of great significance to guide its rational use, reducing/avoiding its potential threat toward food safety and human health. Considering ClO- could quench fluorescence of curcumin (CCM) by oxidizing the o-methoxyphenol of CCM into benzoquinone, a portable ratiometric fluorescence sensor integrated with smartphone was designed for realizing the visual point-of-care testing (POCT) of ClO-. The amphiphilic phospholipid polymer was used as carrier to wrap curcumin, forming a novel liposome-encapsulated CCM, which provided a scaffold to bind with [Ru(bpy)(3)](2+) through electrostatic interaction, thus assembling [Ru(bpy)(3)](2+)-functionalized liposome-encapsulated CCM ([Ru(bpy)(3)](2+)@CCM-NPs). Further integrated with smartphone, visual imaging of [Ru(bpy)(3)](2+)@CCM-NPs could be achieved and the accurate onsite detection of ClO- could be realized with a detection limit of 66.31 nM and a linear range of 0.2210 to 80.0 mu M. In addition, the sensor could monitor ClO- in real samples with an onsite detection time of similar to 154.0 s.

Automated summary

A portable ratiometric fluorescence sensor integrated with a smartphone was developed for the visual point-of-care testing of hypochlorite (ClO-). The sensor showed a low detection limit and a wide linear range, and enabled the rapid onsite detection of ClO- in real samples.