Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, P. O.: R.R.L, Bhubaneswar 751013, Odisha, India; Department of Chemistry, Utkal University, Bhubaneswar 751004, Odisha, India.
Materials Chemistry Department, CSIR-Institute of Minerals and Materials Technology, P. O.: R.R.L, Bhubaneswar 751013, Odisha, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Apr 15;271:120934. doi: 10.1016/j.saa.2022.120934. Epub 2022 Jan 21.
Selective detection of nitroaromatic compounds such as Picric acid (PA), those being explosive materials and hazardous pollutants of environmental and biological concern is highly desirable. With the operational advantages of the chemosensing approach, a pyrene-rhodamine-B couple (1) was explored in this investigation as a ratiometric molecular probe for selective and sensitive detection of picric acid. The bi-fluorophoric probe displayed absorption and fluorescence enhancements along with colourless to reddish-brown colour transition as signaling responses in the selective presence of PA among all the nitro aromatic analyte investigated. The signaling module relies on PA- mediated modulation of various operational photo-physical processes such as (a) inhibition of photo-induced electron transfer (PET) operative from amino-donor to excited pyrene (b) a conformational translation through spiro-ring opening of rhodamine-B segment, and (c) initiation of Fluorescence Resonance Energy Transfer (FRET) between excited pyrene donor and ring-opened rhodamine acceptor. The ratio of fluorescence from both fluorophores (pyrene and Rhodamine) as output channel displayed sensitive signaling performance (LOD = 13.8 nM) in the detection of PA. The investigation that inferred to the PA-induced selectivity in signalling, higher binding affinity (log K≈11), a faster response time, and reversibility in signalling with a counter analyte and an operational pH range established the probe's efficacy as a chemosensor for PA detection.
选择性检测硝基芳香族化合物，如苦味酸（PA），这些都是爆炸物和环境与生物关注的危险污染物，这是非常理想的。本研究探索了一种芘-罗丹明 B 偶联物（1）作为比率型分子探针，用于选择性和灵敏地检测苦味酸，这种偶联物具有化学传感方法的操作优势。双荧光探针在选择性存在 PA 的情况下，表现出吸收和荧光增强以及无色到红棕色的颜色转变等信号响应，在所有研究的硝基芳香族分析物中。信号模块依赖于 PA 介导的各种操作光物理过程的调制，例如：（a）抑制从氨基供体到激发的芘的光诱导电子转移（PET）（b）通过罗丹明 B 片段的螺环开环的构象转化，和（c）在激发的芘供体和开环的罗丹明受体之间引发荧光共振能量转移（FRET）。作为输出通道的两个荧光团（芘和罗丹明）的荧光强度比值显示出对 PA 检测的灵敏信号性能（LOD=13.8 nM）。该研究推断出信号PA 诱导的选择性、更高的结合亲和力（log K≈11）、更快的响应时间和与反分析物的信号可逆性以及操作 pH 范围，确立了该探针作为 PA 检测的化学传感器的功效。
