Construction of highly emissive Schiff base containing TX- 100 nanomicelles for monitoring the levels of devil in disguise Allura red and picric acid in real samples

A sulfonamide derivative synthesized from 1,8-naphthalimide-based amine and 4-methoxy-benzenesulfonyl chloride has been enwrapped into the micelles of a neutral surfactant TX-100 to form highly emissive nanomicelles MXL@TX- 100. The proposed sensor offered highly sensitive turn-off detection of Allura red (linear range = 0.66–224 µM) with the limit of detection (LOD) of 0.2 µM (R² = 0.999) due to fluorescence resonance energy transfer from MXL@TX- 100 to Allura red. To the best of our knowledge, no organic compound-based sensor has been reported for the determination of Allura red so far. Additionally, nanomicelles MXL@TX- 100 were utilized for the sensing of picric acid (LOD = 0.92 µM, R² = 0.998) in the linear range 3.03–928 µM. The binding constant between MXL@TX- 100-Allura red and MXL@TX- 100-picric were calculated to be 1.45 × 10⁵ M⁻¹ and 1.97 × 10⁴ M⁻¹, respectively. Moreover, nanomicelles MXL@TX- 100 conveniently detected Allura red in real samples, viz. candy, soft drink, gulkand, and pharmaceutical syrup.

Graphical Abstract