Ion-induced enhanced fluorescence colorimetric hydrogel sensor for visual quantization of doxycycline

Abstract

The potential hazard to human health caused by antibiotic residues demands a rapid and sensitive detection method. However, the current rapid methods, such as paper-based sensors with reduced detection sensitivity caused by probe solidification due to printing, affect detection accuracy. Here, a hydrogel sensor has been prepared by an ion-induced enhanced optical probe using lutetium ions (Lu3+) coordinated with CdTe quantum dots (QDs). The hydrogel integrates the advantages of the liquid-phase in- situ detection environment and higher accuracy. With the addition of doxycycline (Dox), the β-diketone structure of Dox forms complexes with Lu3+, leading to a change in the Dox molecular structure, and absorbs electrons from QDs that provide a significant color change from red to green. The probe reacts within 2 s with a limit of detection (LOD) of 36.6 nM. Integrated with the advantages of the hydrogel and color analyzer app, the LOD achieved 53.7 nM, which is close to the detection sensitivity in water. On this basis, a smartphone sensing platform has been constructed for the rapid, visual and quantitative analysis of Dox. The hydrogel-based sensing method for rapid visual quantification detection of Dox provides a new strategy for food safety detection.