Selective chromogenic nanomolar level sensing of arsenite anions in food samples using dual binding site probes

K Nagaraj; A Nityananda Shetty; Darshak R Trivedi

doi:10.1016/j.foodchem.2024.141461

Selective chromogenic nanomolar level sensing of arsenite anions in food samples using dual binding site probes

Food Chem. 2024 Sep 27;463(Pt 4):141461. doi: 10.1016/j.foodchem.2024.141461. Online ahead of print.

Authors

K Nagaraj¹, A Nityananda Shetty², Darshak R Trivedi³

Affiliations

¹ Material Science Laboratory, Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal, Srinivasnagar, - 575 025, Karnataka, India; Supramolecular Chemistry Laboratory, Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal, Srinivasnagar- 575 025, Karnataka, India.
² Material Science Laboratory, Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal, Srinivasnagar, - 575 025, Karnataka, India.
³ Supramolecular Chemistry Laboratory, Department of Chemistry, National Institute of Technology Karnataka (NITK) Surathkal, Srinivasnagar- 575 025, Karnataka, India. Electronic address: darshakrtrivedi@nitk.edu.in.

PMID: 39454349
DOI: 10.1016/j.foodchem.2024.141461

Abstract

In the present study, two chromogenic probes, N7R2 and N7R3, each containing two binding sites, were designed and synthesized for the selective detection of arsenite in DMSO/H₂O (1:1, v/v). The probes exhibited stability across a pH range spanning from 5 to 12. The lower detection limits of 2.01 ppb (18.86 nM) for N7R2 and 1.79 ppb (16.75 nM) for N7R3, which are much lower than the WHO recommended permissible limit of arsenite, confirmed the superior efficiency of the probes in detecting arsenite. The detection mechanism for arsenite was proposed through UV and ¹H NMR titrations, electrochemical studies, and DFT calculations. Practical applications were demonstrated through the fabrication of test strips and molecular logic gates. The probes efficiently recognized arsenite in real water, honey, milk samples, and fruit/vegetable juices. Both N7R2 and N7R3 exhibited excellent recovery rates in the analysis of food samples, demonstrating the probes' usefulness in real sample analysis.

Keywords: Arsenite; Colorimetric sensor; DFT; Food samples; Intramolecular charge transfer; Logic gate.