A novel self-supportive thin film based on graphene oxide reinforced chitosan nano-biocomposite for thin film microextraction of fluoxetine in biological and environmental samples.

In this research, for the first time, graphene oxide doped chitosan (GO/CS) nano-biocomposite (NBC) is designed and prepared as a novel self-supportive thin layer for thin film microextraction (TFME) of fluoxetine (FLX) followed by determination applying HPLC-UV-Vis. The properties of the prepared self-supportive thin film were characterized applying ATR-FTIR, FESEM, and XRD techniques. The extraction capability of GO/CS NBC toward FLX has been evaluated, and the obtained results revealed that incorporation of GO into CS has led to higher extraction efficiency in comparison to the CS thin film. After optimizing the effective factors on the extraction efficiency, the figures of merit for the developed method have been evaluated for determination of FLX in various samples. Accordingly, the method's linearity is in the range of 0.4-800 ng mL (R = 0.996), 4-1000 ng mL (R = 0.994), 4-1000 ng mL (R = 0.990), and 6-1000 ng mL (R = 0.993) for deionized water, wastewater, urine and plasma samples, respectively. The limits of detection based on 3 S/N definition was 0.1, 1, 1 and 1.6 ng mL for deionized water, wastewater, urine, and plasma samples, respectively. The repeatability of the developed method has been investigated in the term of intra-day, inter-day and inter-thin film precision and RSD% values for six replicate experiments were obtained 8.6%, 8.4% and 5.7%, respectively. The accuracy of the developed method has been investigated by extraction of FLX from spiked wastewater, plasma and urine samples and the relative recoveries of 104.4%, 87.3% and 82.4% have been resulted, respectively.