Design and synthesis of a carbohydrate-derived chemosensor for selective Ni(II) ion detection: A turn-off approach

Aditi Arora; Sumit Kumar; Shivani Sapra; Gautam Deo; Mrityunjay K Tiwari; Brajendra K Singh; Sandeep Kumar

doi:10.1016/j.carres.2025.109380

Design and synthesis of a carbohydrate-derived chemosensor for selective Ni(II) ion detection: A turn-off approach

Carbohydr Res. 2025 Mar:549:109380. doi: 10.1016/j.carres.2025.109380. Epub 2025 Jan 10.

Authors

Aditi Arora¹, Sumit Kumar¹, Shivani Sapra¹, Gautam Deo², Mrityunjay K Tiwari², Brajendra K Singh³, Sandeep Kumar⁴

Affiliations

¹ Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India.
² Department of Chemistry, University of Delhi, Delhi, 110007, India.
³ Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India. Electronic address: singhbk@chemistry.du.ac.in.
⁴ Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi, 110007, India; Department of Chemistry, Ramjas College, University of Delhi, Delhi, 110007, India. Electronic address: skbanger388@gmail.com.

PMID: 39808908
DOI: 10.1016/j.carres.2025.109380

Abstract

Nickel, an essential transition metal, plays a vital role in biological systems and industries. However, exposure to nickel can cause severe health issues, such as asthma, dermatitis, pneumonitis, neurological disorders, and cancers of the nasal cavity and lungs. Due to nickel's toxicity and extensive industrial use, efficient sensors for detecting Ni²⁺ ions in environmental and biological contexts are essential. Carbohydrates, with their inherent water solubility and biocompatibility, are ideal for constructing chemosensors. Incorporating a pyridyl group enhances the selectivity and sensitivity of these sensors. We present a carbohydrate-derived colorimetric chemosensor 5-(2'-Pyridoylethene-1'-yl)-4-(2''-phenylethene-1''-yl)-2,3-O-isopropylidene-2,3-dihydrofuran-2,3-diol (7a) that exhibits a distinct colour change and significant fluorescence quenching upon binding with Ni²⁺ ions. The synthesis of receptor (7a) was validated by using ¹H, ¹³C NMR, HRMS, and single crystal X-ray analysis. Detection limit of receptor (7a) for Ni²⁺ was calculated to be 0.97 μM, which is below the standard (1.2 μM) set by the United States Environmental Protection Agency (EPA). The binding ratio of receptor (7a) to Ni²⁺ was determined to be 1:1 by using Job's plot. The binding constant of receptor (7a) and Ni²⁺ was calculated as 4.38 × 10⁴ M^-1 by using the Benesi-Hildebrand equation. This sensor demonstrates exceptional selectivity for Ni²⁺ ions over other metal cations. Receptor (7a) is stable and can be used to detect Ni²⁺ in the range of pH from 6 to 10. The sensor responded to Ni²⁺ ions selectively and a large number of coexisting ions showed almost no obvious interference with the detection. Our findings shed light on the potential of carbohydrate-derived chemosensors for nickel detection, paving the way for further exploration in this field. The binding mechanism of receptor (7a) to Ni²⁺ ions was proposed by Job's plot, UV-vis spectra and DFT (Density Functional Theory) calculations.

Keywords: Chemo sensor; Fluorescence quenching; Fluorophores; Metal ions.

MeSH terms

Carbohydrates* / chemical synthesis
Carbohydrates* / chemistry
Colorimetry
Fluorescent Dyes* / chemical synthesis
Fluorescent Dyes* / chemistry
Ions / analysis
Limit of Detection
Nickel* / analysis

Substances

Nickel
Carbohydrates
Fluorescent Dyes
Ions