High-performance NiFe₂O₄/poly-L-cysteine nanocomposite for efficient detection of heavy metals in food samples


Solangi S. A., Höl A., Elçi A., ELÇİ Ş. G., Baig J. A., Perveen S.

Food Chemistry, vol.523, 2026 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 523
  • Publication Date: 2026
  • Doi Number: 10.1016/j.foodchem.2026.150141
  • Journal Name: Food Chemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Chimica, Compendex, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
  • Keywords: Analytical characterization, FAAS, Heavy metals, Milk samples, Nickel ferrite, Poly-L-cysteine, Solid-phase extraction
  • Dokuz Eylül University Affiliated: Yes

Abstract

Nickel ferrite (NiFe2O4)-based poly-L-cysteine (PLC)-functionalized nanocomposite (NiFe2O4/PLC-NC) is a promising material for detecting toxic heavy metals (HMs), including Cd, Co, Ni, and Pb, in milk samples. In the current investigation, nickel ferrite nanoparticles (NiFe₂O₄-NPs) were synthesized via a sol-gel method and subsequently functionalized with PLC to obtain NiFe2O4/PLC-NC. The NiFe2O4/PLC-NC was characterized through various analytical techniques, including Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy, revealing its optimal structure and surface properties. The synthesized NiFe2O4/PLC-NC was employed as an adsorbent to detect HMs in milk samples using a solid-phase extraction-based flame atomic absorption spectrometry method. The experimental results indicated that the adsorption capacity of NiFe2O4/PLC-NC was significantly affected by pH, adsorbent dosage, sample volume, and eluent type. The developed NiFe2O4/PLC-NC-based SPE method exhibited excellent sensitivity and accuracy, with detection limits of 0.0101 μg L−1 for Cd, 0.0236 μg L−1 for Co, 0.0350 μg L−1 for Ni, and 0.0051 μg L−1 for Pb. The NiFe2O4/PLC-NC-based SPE method was validated using certified reference material and real milk samples, demonstrating high analytical accuracy with recoveries exceeding 90% and relative standard deviations below 3.0%. These results confirm that the developed sorbent provides a reliable and efficient platform for the simultaneous determination of HMs in milk samples.