Affiliations 

  • 1 Department of Chemistry, University of Farhangian, Tehran, Iran. M_R_mahmoudian@yahoo.com
  • 2 Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia
  • 3 Department of Physics, Masjed-Soleiman Branch Islamic Azad University (IAU), Masjed Soleyman, 649179658, Iran
  • 4 Department of Chemistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. Yatimah70@um.edu.my
Anal Bioanal Chem, 2019 Jan;411(2):517-526.
PMID: 30498983 DOI: 10.1007/s00216-018-1476-x

Abstract

We report a green synthesis of oatmeal ZnO/silver composites in the presence of L-glutamine as an electrochemical sensor for Pb2+ detection. The synthesis was performed via the direct reduction of Ag+ in the presence of L-glutamine in NaOH. X-ray diffraction indicated that the Ag+ was completely reduced to metallic Ag. The field emission scanning electron microscopy (FESEM) and energy dispersive X-ray results confirmed an oatmeal-like morphology of the ZnO with the presence of Ag. The FESEM images showed the effect of L-glutamine on the ZnO morphology. The EIS results confirmed a significant decrease in the charge transfer resistance of the modified glassy carbon electrode due to the presence of Ag. From the differential pulse voltammetry results, a linear working range for the concentration of Pb2+ between 5 and 6 nM with LOD of 0.078 nM (S/N = 3) was obtained. The sensitivity of the linear segment is 1.42 μA nM-1 cm-2. The presence of L-glutamine as the capping agent and stabilizer decreases the size of Ag nanoparticles and prevents the agglomeration of ZnO, respectively. Graphical abstract ᅟ.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.