Abstract Background: Scopolamine is among the most essential tropane alkaloids used to remedy various nervous system disorders such as urinary incontinence, motion sickness, and spasmodic movements because of its anticholinergic and antispasmodic effects. Objective: In this study, an optical nanosensor was fabricated using nano-Dragendorff’s reagent to detect and determine scopolamine in different plant parts at different stages of growth. Method: For fabrication of the sensing phase, GO-g-PCA/DR was synthesized by encapsulation of Dragendorff’s reagent (DR) on the graphene oxide grafted with poly citric acid (GO-g-PCA) with ultrasonication for 15 min and stirred for 80 min at room temperature, and then it was immobilized on a triacetyl cellulose membrane. The kinetic absorption profiles were recorded at 360 nm, which is concerned with the reaction between immobilized GO-g-PCA/DR and different concentrations of scopolamine. Results: The nanosensor showed a rapid, strong, and stable response to the scopolamine solution with changing the absorption spectrum at 360 nm. The reaction was completed in a period of 300 s. The SEM, AFM, and FT-IR analysis of nanocomposites and nanosensors show the successful synthesis of GO-g-PCA/DR and the reaction between nanosensor and scopolamine. All experiments were performed at the wavelength of 360 nm, room temperature, pH 7 (the scopolamine solution pH), and 300 s. The nanosensor had a linear range of 0.65 to 19.63 lg/mL and 0.19 6 0.025 lg/mL as the limit of detection for scopolamine determination. In order to reuse the designed nanosensor, it was recovered with ethanol, and the color ultimately returned to its original state. Conclusions: This in situ nanosensor can determine the scopolamine in real samples with easy reversibility, extended lifetime, and reproducibility of the sensing phase response.
