Triphenylamine-decorated BODIPY fluorescent probe for trace detection of picric acid

Abstract

Triphenylamine-Decorated BODIPY derivative TBMA was designed and synthesized. Luminogen aggregations were developed through taking advantages of twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) processes. In nonpolar solvents, the locally excited (LE) states of BODIPY luminogens emited intense yellow lights. Increasing solvent polarity brought the luminogens from LE to TICT state, causing a large bathochromic shift in the emission color and a dramatic decrease in emission efficiency. The red emission was greatly boosted by aggregate formation or AIE effect. We also discovered that TBMA could be applied as an efficient chemical sensor for PA detection. The detection limit and quenching constant (K SV ) were determined as 30 ppb and 2.1x10 -6 M -1 respectively. 19 F NMR and 1 H NMR titration analysis verified that F ... H hydrogen bonding is demonstrated as the interacting mode, which is of possibility to facilitates the effective exciton migration.

Turn‐off Fluorescent Sensing of Energetic Materials using Protonic Acid doped Polyaniline: A Spectrochemical Mechanistic Approach

“…This broadening indicates the nature of electron transfer characteristics between P‐PAni and some EMs. [ 41 ] The emission peak at 395 nm for P‐PAni shows a redshift of 2, 5, 6, and 7 nm with RDX, TNT, PETN, and CL‐20, respectively. It is interesting to observe that quenching of peak intensity is prominent but a slow process in TNT compared with other analytes.…”

“…This nature of the plot suggests that the fluorescence quenching process collaborating earlier studies consists of dynamic and static quenching. [ 41 ] Fluorescence quenching efficiency of P‐PAni for different concentrations of EMs is shown in Figure 10 and in Figures S1 to S4 (Supporting Information). The quenching efficiencies were calculated using Equation () below: where I 0 and I are the fluorescence intensities of a fluorophore (P‐PAni), before and after the addition of EMs, respectively (Table 1).…”

“…[ 45 ] Wang et al used square wave voltammetry for detecting NACs by using silica nanoparticles functionalized by polyguanine printed electrode. [ 41 ] Ramanavicius et al discussed and critically optical sensitivity of PAni towards stimulus like pH [ 23 ] and generalized detection studies like metal ions detection (Cu 2+ ) employing cyclic voltammetry. [ 26 ] In the present cyclic Voltammetric study was carried out to understand electrochemical oxidation/reduction occurring of P‐PAni chain.…”

“…Literature for similar studies on fluorescence detection of analytes employing typical conducting polymers confirms that a combination of the two mechanisms, i.e., a static and a dynamic, is generally observed. [ 41 ] The R 2 values calculated from the SV plots are found to be 0.847, 0.902, 0.917, and 0.946 for TNT, RDX, CL‐20, and PETN, respectively. The nonlinearity of the analytes plot may be a result of either an energy‐transfer process or self‐absorption.…”

Protonation- and electrostatic-interaction-based fluorescence probes for the selective detection of picric acid (2,4,6-trinitrophenol) – an explosive material

“…BODIPY derivative 126121 (chart 16) in the presence of 500 equivalents of PA displayed 95 % quenching in emission intensity at 600 nm due to enhancement in intermolecular PET. The down-field shift of 19 F NMR signal in the presence of PA supported hydrogen bonding between fluorine and phenolic hydrogen of PA. All other NAC's gave less than 30% fluorescence quenching.…”