Tewary Debendra, Behera Kanhu Charan, Turner David R, Ravikanth Mangalampalli
Department of Chemistry, IIT Bombay, Powai-400076, Mumbai, India.
IITB- Monash Research Academy, IIT Bombay, Powai-400076, Mumbai, India.
Phys Chem Chem Phys. 2024 Aug 28;26(34):22479-22490. doi: 10.1039/d4cp02715a.
A series of pyridyl-coupled 3-pyrrolyl BODIPY fluoroprobes were synthesized by varying the position of the pyridyl/-methylated pyridyl group at the α-/-position of the 3-pyrrolyl BODIPY scaffold and thoroughly characterized by HRMS and 1D/2D NMR techniques. Our studies indicated that only the water-soluble -methylated -pyridyl 3-pyrrolyl BODIPY among various pyridyl-coupled 3-pyrrolyl BODIPYs synthesized here showed an effective and exclusive sensing for picric acid (HPA). The -methylated -pyridyl 3-pyrrolyl BODIPY rapidly detects HPA in an aqueous medium with exceptional selectivity, sensitivity (LOD = 7.90 pM), and high binding affinity ( = 4·94 × 10 M) through both chromogenic and fluorogenic signalling modes. Our studies support the formation of a charge transfer complex between cationic -methylated -pyridyl 3-pyrrolyl BODIPY and picrate as verified by absorption, fluorescence, electrochemical, and NMR techniques. DFT and TD-DFT studies further support the structural and experimental observations, including the sensing mechanism of HPA.
通过改变吡啶基/甲基化吡啶基在3-吡咯基BODIPY支架α-位/β-位的位置，合成了一系列吡啶基偶联的3-吡咯基BODIPY荧光探针，并通过高分辨质谱（HRMS）和一维/二维核磁共振（1D/2D NMR）技术进行了全面表征。我们的研究表明，在此合成的各种吡啶基偶联的3-吡咯基BODIPY中，只有水溶性的β-甲基化-α-吡啶基3-吡咯基BODIPY对苦味酸（HPA）表现出有效且专一的传感性能。β-甲基化-α-吡啶基3-吡咯基BODIPY通过显色和荧光信号模式，在水性介质中能快速检测HPA，具有出色的选择性、灵敏度（检测限=7.90 pM）和高结合亲和力（K = 4.94×10⁶ M⁻¹）。我们的研究支持阳离子型β-甲基化-α-吡啶基3-吡咯基BODIPY与苦味酸盐之间形成电荷转移络合物，这已通过吸收、荧光、电化学和核磁共振技术得到证实。密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）研究进一步支持了结构和实验观察结果，包括HPA的传感机制。
