Tekuri, V.Trivedi, D.R.2026-02-052017Analytica Chimica Acta, 2017, 972, , pp. 81-9332670https://doi.org/10.1016/j.aca.2017.03.035https://idr.nitk.ac.in/handle/123456789/25599A new heterocyclic thiophene-2-caboxylic acid hydrazide based chemosensor R1 to R4 were designed, synthesized and characterized by various spectroscopic techniques like FT-IR, UV-Vis, 1H NMR, 13C NMR, Mass and SC-XRD. The chemosensor R3 showed a significant color change from colorless to yellow in the presence of Cu2+ ions and chemosensor R4 showed a significant color change from colorless to yellow in the presence of Cd2+ ions over the other tested cations such as Cr3+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Zn2+, Ag2+, Al3+, Pb2+, Hg2+, K+, Ca2+ and Mg2+. The high selective and sensitivity of R3 towards Cu2+ and R4 towards Cd2+ ions was confirmed by UV-Vis spectroscopic study. The R3 showed a red shift in the presence of Cu2+ ions by ??<inf>max</inf> 67 nm and R4 showed a red shift in the presence of Cd2+ ions by ??<inf>max</inf> 105 nm in the absorption spectrum. The binding stoichiometric ratio of the complex between R3 - Cu2+ and R4 - Cd2+ ions have been found to be 1:1 using the B-H plot. Under optimized experimental conditions, the R3 and R4 exhibits a dynamic linear absorption response range, from 0 to 50 ?M for Cu2+ ions and 0 to 30 ?M for Cd2+ ions, with the detection limit of 2.8 × 10?6 M for Cu2+ and 2.0 × 10?7 M for Cd2+ ions. The proposed analytical method for the quantitative determination of Cu2+ and Cd2+ ions was validated and successfully applied for the environmental samples with good precision and accuracy. © 2017 Elsevier B.V.Absorption spectroscopyColorColorimetryDoppler effectPhysiologySpectroscopic analysisSynthesis (chemical)Analytical method validationAssociation constantColorimetric chemosensorEnvironmental water samplesExperimental conditionsQuantitative determinationsSpectroscopic studiesSpectroscopic techniqueIonscadmiumcupric ionabsorption spectroscopyArticleassociation constantbinding affinitycolorimetrycontrolled studyinfrared spectroscopylimit of detectionlimit of quantitationlinear systemmeasurement accuracymeasurement precisionpriority journalprocess optimizationquantitative analysisstoichiometrystructure analysisultraviolet spectroscopyvalidation processwater sampling