ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A rapid and sensitive method to detection of Cr³⁺by using the Fe₃O₄@Pectin-polymethacrylimide@graphene quantum dot as a sensitive material

Mehdi Barzegarzadeh, Mohammad Sadegh Amini-Fazl, and Hossein Nasrizadeh

Advanced Polymer Material Research Laboratory, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran

E-mail: ms.amini@tabrizu.ac.ir

Received: 6 June 2022  Accepted: 10 September 2022

Abstract:

The issue of residual heavy metals in environmental and water sources is a global challenge. Among heavy metals, chromium is a very dangerous metal that is very harmful to humans and all living things. Exposure may occur from natural or industrial sources of chromium. Therefore, designing an optical sensor to monitor Cr³⁺ ions in an aqueous solution with selectivity, simplicity, and high sensitivity is of great importance. In the present work, free radical polymerization is used to synthesize a magnetic Fe₃O₄@Pectin-polymethacrylamide@graphene quantum dot (Fe₃O₄@Pectin-MAM@GQD) nanocomposite with a core–shell structure. It is used as an optical nanosensor for the detection of Cr³⁺ ions in aqueous solutions. This method is based on increasing the UV–vis absorbance intensity of Fe₃O₄@Pectin-MAM@GQD in the presence of Cr³⁺ ions. At optimal conditions, pH = 6 and adsorbent dose of 0.3 mg/ml, the synthesized nanosensor showed a good linear correlation between the absorbance intensity of the nanosensor and the concentrations of Cr³⁺ in the range from 4 to 100 µM. Remarkably, the result showed that the LOD and LOQ of Fe₃O₄@Pectin-MAM@GQD nanocomposite are equal to 0.468 µM and 1.419 µM, receptively. Using this method can identify chromium in aqueous pollutants since a low limit of detection of chromium in aqueous solutions (MRL≈1 µM, WHO).

Keywords: Graphene quantum dot; Heavy metal detection; Pectin; Polymethacrylamide; Nanosensor

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02484-7

Chemical Papers 77 (1) 351–360 (2023)