Abstract：
Chromium is essential for some biochemical processes, and excess is a big concern that shows adverse effects on human health and the environment. Therefore, it is urgent to design new sensors to detect chromium ions rapidly. The present study discusses the synthesis of piperazine conjoined 1,2,3-triazolyl-γ-propyltriethoxysilanes (4a-4b) and development of 4a as fluorescence turn-on sensor for the detection of Cr3+ ions. The mechanistic insights reveal to the restricted CN rotation and inhibited intramolecular charge transfer (ICT) process. In addition, Job\'s plot and Benesi-Hildebrand plot justify the 1:1 binding affinity with a binding constant of 9.96 × 105 M-1 for [ligand 4a + Cr3+] complex and the limit of detection for Cr3+ ions is observed as 6.06 × 10-8 M. The fluorescence spectral changes, 1H NMR spectra and DFT studies provide evidences for ligand 4a and Cr3+ ions interactions. Further, the reversibility of the ligand 4a from [ligand 4a + Cr3+] complex on the addition of EDTA can be used in the construction of molecular logic gate where Cr3+ and EDTA are considered as inputs and the fluorescence intensity at 398 nm as output. Further, compounds 4a-4b were then evaluated for their antibacterial activity against bacterial strains (Escherichia coliand Staphylococcus aureus), revealing a modest activity. The binding mode of ligand 4a to Staphylococcus aureus (PDB ID - 3U2K) and Escherichia coli (PDB ID - 5Z4O) was investigated using an in-silico molecular docking technique, which revealed that the triazole ring and silanyl group are involved in hydrogen bonding with proteins and may be the cause of the ligand\'s antibacterial activity. The ligand 4a demonstrated a high affinity for binding within the active sites of proteins with binding energies of -7.97 kcal/mol (3U2K) and -8.68 kcal/mol (5Z4O).
摘要：
铬对某些生化过程至关重要，和过量是一个大问题，显示对人类健康和环境的不利影响。因此,迫切需要设计新型的快速检测铬离子的传感器。本研究讨论了哌嗪结合1,2,3-三唑基-γ-丙基三乙氧基硅烷（4a-4b）的合成，以及4a作为检测Cr3离子的荧光开启传感器的开发。机理见解揭示了受限的CN旋转并抑制了分子内电荷转移（ICT）过程。此外,Job\'s图和Benesi-Hildebrand图证明了[配体4aCr3]复合物的1：1结合亲和力，结合常数为9.96×105M-1，对Cr3离子的检测极限为6.06×10-8M。荧光光谱变化，1HNMR光谱和DFT研究为配体4a和Cr3离子相互作用提供了证据。Further,添加EDTA后[配体4aCr3]配合物的配体4a的可逆性可用于构建分子逻辑门，其中Cr3和EDTA被视为输入，398nm处的荧光强度作为输出。Further,然后评估化合物4a-4b对细菌菌株（大肠杆菌和金黄色葡萄球菌）的抗菌活性，揭示了一个适度的活动。使用计算机分子对接技术研究了配体4a与金黄色葡萄球菌（PDBID-3U2K）和大肠杆菌（PDBID-5Z4O）的结合模式。这表明三唑环和硅烷基参与与蛋白质的氢键键合，可能是配体抗菌活性的原因。配体4a显示出在蛋白质活性位点内结合的高亲和力，结合能为-7.97kcal/mol（3U2K）和-8.68kcal/mol（5Z4O）。
