Dharaniprabha V, Elango Kuppanagounder P
Department of Chemistry, Gandhigram Rural Institute (Deemed To Be University), Gandhigram, 624302, India.
J Fluoresc. 2025 May 5. doi: 10.1007/s10895-025-04348-1.
This endeavour's novel Schiff base VDP3 is a fruitful candidate for colourimetric/fluorometric detection of cyanide and fluorometric detection of Al(III) ions in a 50% aqua-organic medium. The prompt naked eye colour change (yellow to orange) and noteworthy fluorescence enhancement of VDP3 in the presence of CN avowed that VDP3 was an exemplary probe for detecting CN with a low detection limit of 0.4 µM. The NMR studies infer that deprotonation followed by nucleophilic addition is the probable sensing mechanism for detecting CN by VDP3. The faint fluorescence of VDP3 was owing to the photoinduced electron transfer (PET), and the nucleophilic addition of CN intervenes with the PET and consequently enhances the fluorescence significantly. The VDP3 selectively detects Al(III) by forming the chelate octahedral complex [Al(VDP3)(HO)] as witnessed by the Al-NMR, H-NMR, and mass spectral studies with a LOD of 0.14 µM. The striking fluorescent enhancement for VDP3 + Al(III) was ascribed to the collective impacts of PET-CHEF mechanisms (PET-OFF/CHEF-ON). The experimental findings and expected sensing mechanism for detecting CN and Al(III) were upheld by the computational studies, and they provide robust evidence for the PET ON and PET OFF mechanisms to explain the fluorescence enhancement behaviour further. The VDP3 was proficiently applied for quantitatively estimating CN and Al(III) in real-world samples. Additionally, VDP3 was effectively utilised for the qualitative and quantitative assessment of cyanide in cassava flour through a simple and convenient colourimetric method without any complex instruments.
这种新型席夫碱VDP3是一种很有成效的候选物，可用于在50%的水-有机介质中比色/荧光检测氰化物以及荧光检测铝离子（Al(III)）。在氰根（CN）存在下，VDP3迅速出现肉眼可见的颜色变化（从黄色变为橙色）且荧光显著增强，这表明VDP3是一种检测氰根的典型探针，检测限低至0.4 μM。核磁共振（NMR）研究推断，去质子化后接着亲核加成是VDP3检测氰根的可能传感机制。VDP3微弱的荧光归因于光诱导电子转移（PET），而氰根的亲核加成干扰了PET，从而显著增强了荧光。如铝核磁共振（Al-NMR）、氢核磁共振（H-NMR）和质谱研究所示，VDP3通过形成螯合八面体配合物[Al(VDP3)(HO)]选择性地检测铝离子（Al(III)），检测限为0.14 μM。VDP3 + Al(III)显著的荧光增强归因于PET-CHEF机制（PET-OFF/CHEF-ON）的共同作用。计算研究支持了检测氰根和铝离子（Al(III)）的实验结果及预期传感机制，它们为PET开启和PET关闭机制提供了有力证据，以进一步解释荧光增强行为。VDP3被成功应用于实际样品中氰根和铝离子（Al(III)）的定量测定。此外，VDP3通过一种简单便捷的比色法有效地用于木薯粉中氰化物的定性和定量评估，无需任何复杂仪器。
