S Vishnu, Das Avijit Kumar, Bylappa Yatheesharadhya, Nag Anish, Dolai Malay
Department of Chemistry, Christ University, Hosur Road, Bangalore, Karnataka, 560029, India.
Department of Life Science, Christ University, Hosur Road, Bangalore, Karnataka, India, 560029.
Anal Methods. 2024 Dec 5;16(47):8164-8178. doi: 10.1039/d4ay01758g.
A multifunctional rhodamine derivative containing azo-salicylaldehyde (BBS) was designed and synthesized as a colorimetric and fluorescence turn-on probe for the selective detection of copper cations (Cu) and hypochlorite anions (OCl) in aqueous media. In the presence of Cu, the probe BBS exhibited turn-on absorption and fluorescence change at 554 nm and 585 nm, respectively. The binding mechanism of BBS with Cu induces the opening of a spirolactam ring in the rhodamine moiety by the formation of a metal-ligand complex, achieving 10-fold enhancement in fluorescence and quantum yield, along with a binding constant of 1 × 10 M and a detection limit of 2.61 μM. Addition of OCl enhanced the absorbance and fluorescence intensities at 520 nm and 575 nm, respectively. The probe BBS underwent hypochlorite-mediated oxidation, followed by hydrolysis, resulting in the formation of rhodamine B itself, which is detectable by the naked eye the color and fluorescence enhancement by 11-fold with a high quantum yield and a detection limit of 1.96 μM. For practical applications, sensor BBS can be used to detect Cu in water samples and on cotton swabs. For biological applications, the interaction of the BBS-Cu(II) complex with transport proteins such as bovine serum albumin (BSA) and ct-DNA was investigated through UV-vis and fluorescence titration experiments. Additionally, the structural optimization of BBS and the BBS-Cu(II) complex was demonstrated using DFT, and the interactions of the BBS-Cu(II) complex with BSA and ct-DNA were analysed through theoretical docking studies. Bioimaging studies were conducted by capturing fluorescence images of BBS with Cu and OCl in a physiological medium containing living plant tissue using green gram seeds.
设计并合成了一种含偶氮水杨醛的多功能罗丹明衍生物（BBS），作为比色和荧光开启型探针，用于在水性介质中选择性检测铜离子（Cu）和次氯酸根阴离子（OCl）。在Cu存在下，探针BBS分别在554 nm和585 nm处表现出吸收开启和荧光变化。BBS与Cu的结合机制通过形成金属-配体络合物诱导罗丹明部分的螺内酰胺环打开，实现荧光和量子产率提高10倍，结合常数为1×10 M，检测限为2.61 μM。加入OCl分别增强了520 nm和575 nm处的吸光度和荧光强度。探针BBS经历次氯酸盐介导的氧化，随后水解，导致罗丹明B本身形成，肉眼可检测到颜色和荧光增强11倍，量子产率高，检测限为1.96 μM。在实际应用中，传感器BBS可用于检测水样和棉签上的Cu。在生物应用方面，通过紫外可见和荧光滴定实验研究了BBS-Cu（II）络合物与牛血清白蛋白（BSA）和ct-DNA等转运蛋白的相互作用。此外，使用密度泛函理论（DFT）证明了BBS和BBS-Cu（II）络合物的结构优化，并通过理论对接研究分析了BBS-Cu（II）络合物与BSA和ct-DNA的相互作用。通过使用绿豆种子在含有活植物组织的生理介质中捕获BBS与Cu和OCl的荧光图像进行了生物成像研究。
