Palanisamy Prasanth, Anandan Mageshwari, Raman Gurusamy, Nutalapati Venkatramaiah
Functional Materials Laboratory, Department of Chemistry, College of Engineering and Technology, SRM Institute of Science and Technology (SRMIST), Kattankulathur, Tamil, Nadu- 603203, India.
Department of Life Sciences, Yeungnam University, Gyeongsanbuk-Do, Gyeongsan, 38541, Republic of Korea.
Mikrochim Acta. 2024 Dec 2;192(1):1. doi: 10.1007/s00604-024-06795-2.
Two modular systems were synthesized composed of triphenylamine (ZnTPAP) and pyrene (ZnPyP) covalently linked at meso position of the Zn(II) porphyrins. Both compounds behaved as energy transfer antenna and orthogonal units to enhance the electron donating ability of Zn(II) porphyrins. Detailed photophysical and aggregation studies reveal that an appreciable electronic interaction exists between peripheral units to the porphyrin π-system so that they behave like strong donor materials. The electrochemical and computational studies demonstrate delocalization of the frontier highest occupied molecular orbital (-5.08 eV) over the triphenylamine entities (ZnTPAP) in addition to the porphyrin macrocycle. Fluorescence experiments with ZnTPAP and ZnPyP in the presence of different nitro analytes at various concentrations show turn-off fluorescence behaviour and exhibit superior selectivity towards 2,4-dinitrophenol (DNP) with limit of detection (LOD) of ~ 2.3 and 9.2 ppm for ZnTPAP and ZnPyP. Photoinduced electron transfer process is involved in the static and dynamic fluorescence quenching process. A Stern-Volmer quenching association constant (K) determination revealed that ZnTPAP is more sensitive than the ZnPyP. This is attributed to the strong donating behaviour of TPA units caused by intermolecular interaction through metal center and strong π-π interactions with nitro analytes. The present study provides new insights into the ability to tune the affinity and selectivity of porphyrin-based sensors utilising electronic factors associated with the central Zn(II) ion. Furthermore, a smartphone-interfaced portable fluorimetric method by recognising colour variations in RGB and the luminance (L) values facilitate sensitive and real-time sensing at low concentration levels will have a significant impact on development of a new class of chemosensors.
合成了两个模块化体系，它们由在锌（II）卟啉的中位共价连接的三苯胺（ZnTPAP）和芘（ZnPyP）组成。这两种化合物都表现为能量转移天线和正交单元，以增强锌（II）卟啉的供电子能力。详细的光物理和聚集研究表明，外围单元与卟啉π体系之间存在明显的电子相互作用，因此它们表现得像强供体材料。电化学和计算研究表明，除了卟啉大环外，前沿最高占据分子轨道（-5.08 eV）在三苯胺实体（ZnTPAP）上也有离域。在不同浓度的不同硝基分析物存在下对ZnTPAP和ZnPyP进行的荧光实验显示出荧光猝灭行为，并且对2,4-二硝基苯酚（DNP）表现出优异的选择性，ZnTPAP和ZnPyP的检测限（LOD）分别约为2.3和9.2 ppm。光诱导电子转移过程参与了静态和动态荧光猝灭过程。斯特恩-沃尔默猝灭缔合常数（K）的测定表明，ZnTPAP比ZnPyP更敏感。这归因于TPA单元通过金属中心的分子间相互作用以及与硝基分析物的强π-π相互作用而产生的强供体行为。本研究为利用与中心锌（II）离子相关的电子因素调节基于卟啉的传感器的亲和力和选择性的能力提供了新的见解。此外，一种通过识别RGB颜色变化和亮度（L）值的智能手机接口便携式荧光方法，有助于在低浓度水平下进行灵敏和实时传感，这将对新型化学传感器的开发产生重大影响。
