Carbon nanomaterial-modified PVA electrospun nanofibers for extraction of trace heavy metals from environmental and food samples

Herein, poly(vinyl alcohol) (PVA) electrospun nanofibers were functionalized with multi-walled carbon nanotubes/graphene oxide (MWCNTs/GO) to fabricate an efficient and water-insoluble sorbent for thin film microextraction (TFME) of three metal ions (Cd (II), Co(II), and Zn(II)), followed by atomic absorption spectroscopy (AAS). Incorporating MWCNTs and GO endows the sorbent with high surface area and significant adsorption capacity. Under optimal conditions, satisfactory linearity was observed in the concentration range of 6.0–1000.0 ng mL⁻¹ (R² ≥ 0.9928), while the limits of detection (LODs), based on a signal-to-noise ratio of 3, ranged from 2.0 to 3.0 ng mL⁻¹. The relative standard deviations (RSDs) ranged from 5.9–6.6% for intra-day measurements (n = 5) and from 6.0% to 7.1% for inter-day measurements over three consecutive days (n = 3). The developed method was applied to water, soil, and vegetable samples, and the recoveries (90.8% to 98.9%) demonstrated that the PVA/CA/MWCNTs/GO film is a promising adsorbent for heavy metal ions in diverse sample matrices. Schematic presentation of fabrication of a) PVA/CA/MWCNT/GO composite, and b) applying PVA/CA/MWCNT/GO composite nanofibers as the sorbent in thin film micro extraction (TFME). • PVA electrospun nanofibers were successfully functionalized with MWCNT/GO. • The sorbent was utilized for extraction of trace-level of metal ions in real samples. • The incorporation of MWCNT/GO increases the nanofibers extraction efficiency. • This method is eco-friendly thanks to low eluent consumption.