ItemArticle

A turn-on bis-hydrazone fluorescent chemosensor for selective Cd2+ detection: synthesis, structural insights, and theoretical validation

Title
A turn-on bis-hydrazone fluorescent chemosensor for selective Cd2+ detection: synthesis, structural insights, and theoretical validation
Creator
Adhikari, Suman; Nath, Sourav; Saha, Koushik; Baildya, Nabajyoti; Kaminsky, Werner; Kumar, Malavika S; Roy, Subhadip; Das, Avijit Kumar
Description
Heavy metal pollution, particularly from cadmium(ii) ions (Cd2+), causes severe environmental and health risks due to its acute toxicity, carcinogenicity, and bioaccumulation, leading to kidney damage, neurological disorders, and other physiological issues. Herein, we report the one-pot synthesis of a bis-hydrazone-based fluorescent probe L2H2O (1) for selective detection of Cd2+. Probe 1 was derived from isophthalaldehyde and 3-pyridylcarbonyl hydrazine and single-crystal X-ray diffraction discloses a well-defined binding pocket with pyridyl, imine, and carbonyl donor sites suitable for Cd2+ coordination. Probe 1 exhibits weak emission in CH3CN/HEPES buffer (9?:?1, v/v, pH 7.4) due to photoinduced electron transfer (PET) and unrestricted intramolecular rotations. Upon selective binding to Cd2+, 1 displays a pronounced turn-on fluorescence response with intensity enhancements of at ?324 nm and at 420 nm, accompanied by bathochromic shifts to 327 nm (?? = 3 nm) and 445 nm (?? = 25 nm) (?ex = 295 nm). The limit of detection (LOD) for probe 1 with metal Cd2+ is 3.39 M, with a binding constant of 5 103 M?1. 1H NMR titration, DFT-optimized geometries (B3LYP/6-31+G(d)/LANL2DZ), and simulated UV-Vis spectra further confirm binding of Cd2+, blocking PET and rigidifying the structure via chelation-enhanced fluorescence (CHEF). This work presents a modular hydrazone scaffold for developing selective Cd2+ sensors with potential application in environmental and biological monitoring. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique, 2026.
Source
New Journal of Chemistry;
Date
01-01-2026
Publisher
Royal Society of Chemistry
Coverage
Adhikari S., Department of Chemistry, Govt. Degree College, Tripura, Dharmanagar, (N)-799253, India; Nath S., Department of Chemistry, Govt. Degree College, Tripura, Dharmanagar, (N)-799253, India, Department of Chemistry and Vivekananda Centre for Research, Ramakrishna Mission Residential College, Narendrapur, Kolkata, 700103, India; Saha K., Department of Chemistry, Jadavpur University, West Bengal, Kolkata, 700032, India; Baildya N., Department of Chemistry, Milki High School, Milki, Malda, 732209, India; Kaminsky W., Department of Chemistry, University of Washington, Seattle, 98195, Washington, United States; Kumar M.S., Department of Chemistry, Christ University, Hosur Road, Karnataka, Bangalore, 560029, India; Roy S., Department of Chemistry, The ICFAI University Tripura, Kamalghat, Mohanpur, Tripura, Agartala, 799210, India; Das A.K., Department of Chemistry, Christ University, Hosur Road, Karnataka, Bangalore, 560029, India
Rights
Restricted Access; Hardcopy may be available in the library
Relation
ISSN: 11440546; CODEN: NJCHE
Format
online
Language
English
Type
Article

Citation

Adhikari, Suman; Nath, Sourav; Saha, Koushik; Baildya, Nabajyoti; Kaminsky, Werner; Kumar, Malavika S; Roy, Subhadip; Das, Avijit Kumar, “A turn-on bis-hydrazone fluorescent chemosensor for selective Cd2+ detection: synthesis, structural insights, and theoretical validation,” CHRIST (Deemed To Be University) Institutional Repository, accessed June 17, 2026, https://archives.christuniversity.in/items/show/22604.

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