Polydiacetylene/triblock copolymer/surfactant nanoblend: A simple and rapid method for the colorimetric screening of enrofloxacin residue.

Highlights • Polydiacetylene (PDA)/triblock copolymer (TC)/surfactant (SDS) formed nanosensor. • Enrofloxacin (ENRO) induced a colorimetric transition (CT) in the PDA/TC/SDS sensor. • Energy released by ENRO–SDS interaction was the driving force for PDA color change. • Limit of detection of sensor to ENRO was five times smaller than the allowed by EU. • PDA/TC/SDS sensor shows potential to be applied for detecting ENRO in foods. Abstract Colorimetric nanosensors formed of polydiacetylene (PDA), triblock copolymer (L64 or F68), and sodium dodecyl sulfate (SDS), so-called nanoblends, were developed to detect enrofloxacin (ENRO) in aqueous media. The nanosensors show hydrodynamic diameter ranging from 234.2 ± 3.5 to 801.6 ± 17.8 nm for SDS concentrations of 13.0–21.0 mM, respectively. The lowest limit of detection was 0.054 µM, which is five times smaller than the maximum limit allowed by the European Union. The response surfaces showed that both the SDS and ENRO concentrations influenced the colorimetric response (p < 0.05), and kinetic rate of colorimetric transition (R CT). SDS concentration between 11.0 and 14.0 mM in the nanoblend yielded the most sensitive nanosensors for detecting ENRO. When L64 was replaced by F68, the colorimetric response of the nanoblends was similar, but PDA/F68/SDS showed a slower R CT than PDA/L64/SDS. The developed nanosensor is a sensitive and simple device for the fast detection of ENRO. [ABSTRACT FROM AUTHOR]