Determination of chromium(III) in aqueous solution using CePO₄:Tb³⁺ nanocrystals in a fluorescence resonance energy transfer system

Abstract

Trivalent chromium is an essential element required for normal carbohydrate, lipid and protein metabolism in humans and animals. This article describes an efficient fluorescence resonance energy transfer (FRET) system between CePO4 :Tb(3+) nanocrystals as the donor and chromium(III) as the acceptor. CePO4 :Tb(3+) nanocrystals were synthesized in aqueous solution, and characterized by transmission electron microscopy. Under optimum conditions, a linear calibration graph was obtained (R(2) = 0.996). The linear range and detection limit of chromium(III) were 0.01-2.2 μM, and 9.1 nM, respectively. The proposed method had a wide linear range and proved to be very sensitive, rapid and simple. Moreover, the method was applied successfully to the determination of chromium(III) in synthetic samples and tap water.

Design and synthesis of a novel chromium(III) selective fluorescent chemosensor bearing a thiodiacetamide moiety and two rhodamine B fluorophores

“…The chemical structure of RBTDA was analyzed by 1 H NMR, 13 C NMR and HRMS. The 1:1 coordination mode was proposed based on a Job plot, 1 H NMR titration experiments and ES(+)-MS analyses.…”

“…19 (t, J 1 = 6.65 Hz, J 2 = 6.6 Hz, 2H), 2.41 (t, J 1 = 6.65 Hz, J 2 = 6.6 Hz, 2H), 1.16 (t, J 1 = 7.0 Hz, J 2 = 7.1 Hz, 12H) ppm. 13 6.45 (d, J = 8.8 Hz, 4H), 6.37 (d, J = 2.5 Hz, 4H), 6.28 (dd, J = 8.9, 2.6 Hz, 4H), 3.38-3.26 (m, 20H), 3.14 (s, 4H), 3.06 (q, J = 5.3 Hz, 4H), 2.04 (s, 2H), 1.16 (t, J 1 = 7.0 Hz, J 2 = 7.1 Hz, 24H). 13 …”

“…All of the solvents were of analytical grade, and deionized water was used in all of the experiments. The salts used to prepare the metal ion stock solutions included AgNO 3 1 H (500 MHz) and 13 C NMR (126 MHz) spectra were recorded on an Avance 500 spectrometer (Bruker; Billerica, MA, USA). The chemical shifts are reported in ı units (ppm) downfield relative to the chemical shift of tetramethylsilane.…”

“…Compound 1 was prepared in 92% yield by refluxing commercially available rhodamine B with ethane-1, 2-diamine in EtOH. RBTDA was prepared in 82% yield by the reaction of 1 with thiodiglycolic acid in the presence of DCC, HOBt, and DIPEA in CH 2 Cl 2 at room temperature for 12 h. The structure of RBTDA was confirmed by 1 H NMR, 13 C NMR and HRMS (Supporting materials, S1-S5).…”

“…In contrast to its higher oxidation state (Cr 6+ , which is very toxic and mutagenic [10]), Cr 3+ is less harmful to human life [11]. However, either a Cr 3+ deficiency or an excess amount of Cr 3+ can induce biological disorders in the human body [12,13]. For example, exposure to higher concentrations of Cr 3+ has a negative effect on normal enzymatic activities [14].…”