An optical material for the detection of β-hydroxybutyrate based on a terbium complex

• A novel luminescence enhanced sensor for β-hydroxybutyrate (β-HB) is developed based on a Tb3+ complex (TbL2).
• A 1:1 binding model between TbL2 and β-HB is proposed.
• The binding constant of TbL2-β-HB is 9.3 × 105 M−1.

A novel Tb3+ complex (Tb(C14H10O4)⋅Cl, TbL2) based on benzoic acid (L+H) was successfully synthesized, and gave a weak green emission in methanol–water (V:V, 4:1, pH 4.49). With the addition of β-hydroxybutyrate (β-HB) to a semi-aqueous solution of TbL2, an increment of the luminescent intensity at 545 nm assigned to 5D4 → 7F5 transition of Tb3+ was measured, which was evident to the naked eye. The response showed high selectivity for β-HB compared with other common anions including Cl−, NO3-, CO32-, PO43-, HPO42-, H2PO4-, C2O42-, P2O74-, SO42-, lactate, AcO−, citrate, malate therefore it has the potential to be applied as a luminescent sensor for β-HB.

The luminescent responses of TbL2 (0.08 mM) with various anions in methanol -water (V:V, 4:1, pH 4.49). Bars represent the relative luminescence intensity ratio of 545 nm to 485 nm of TbL2 (0.08 mM) with the addition of 3 equivalent various common anions. (λex = 240 nm)Figure optionsDownload high-quality image (43 K)Download as PowerPoint slide