A Naphthalimide-Benzothiazole Conjugate as Colorimetric and Fluorescent Sensor for Selective Trinitrophenol Detection

Abstract

Although chemical structural modification of naphthalimides is widely employed for the purpose of sensing explosives, the effects of such modification have been little explored. Herein, we report the design and synthesis of a new naphthalimide-benzothiazole conjugate (1) and its ability to sense various nitrophenols by means of its colorimetric and fluorescent characteristics. Under long-range UV light (365 nm), 1 displayed a color change of its solution from bluish to colorless only upon addition of 2,4,6-trinitrophenol (TNP). Photoluminescence spectroscopy showed quantitative fluorescence quenching by TNP of the emission peaks of 1 at 398 nm and 418 nm due to donor–acceptor electron transfer. The interaction of 1 with TNP was via a cooperative, non-covalent hydrogen-bonding interaction. Receptor 1 exhibited high sensitivity and selectivity towards TNP over various aromatic nitro analytes. The binding constant (K) and Stern–Volmer constant (Ksv) between 1 and TNP were found to be 5.332 × 10−5 M and 2.271 × 106 M−1, respectively. Furthermore, the limit of detection was calculated and found to be as low as 1.613 × 10−10 M.

Explicating the recognition phenomenon of hazardous nitro-aromatic compound from contaminated environmental and cellular matrices by rationally designed pyridine-functionalized molecular probes

“… TNP 0.12 μM H 2 O – – [ 55 ] 3. DNP, TNP 0.1613 μM Acetonitrile – – [ 26 ] 4. Cu 2+ , TNP 0.35 μM Acetonitrile – In-vitro detection for Cu 2+ [ 38 ] 5.…”

“…Simultaneously, other fluorescent probes, like microporous metamemeworks (MOFs), dual-emission quantum dot hybrids, fluorescent film sensors, and conjugated polymers (CPs) are less viable owing to aggregation-caused quenching (ACQ), where the fluorescence intensity diminishes in presence of higher extent of luminophores [ 24 , 25 ]. As a consequence, the design and synthesis of luminescent small organic sensors can be a cutting-edge choice for developing more advantageous proficient chemosensors [ [25] , [26] , [27] , [28] ]. In this aspect, Schiff-base chemosensors, can be a potential contender for recognizing TNP due to their ease of synthesis, simplicity, high yield, stability, and tunability [ 29 , 30 ].…”

Spectral Characteristics and Sensor Ability of a New 1,8-Naphthalimide and Its Copolymer with Styrene

“…The final product (NI3) was obtained after nucleophilic substitution of the nitro group from NI2 with an allylamino group. The chemical structure of the new compound NI3 was characterized by FTIR, 1 H and 13 C NMR spectra, as well as an elemental analysis.…”

“…The final product (NI3) was obtained after nucleophilic substitution of the nitro group from NI2 with an allylamino group. The chemical structure of the new compound NI3 was characterized by FTIR, 1 H and 13 C NMR spectra, as well as an elemental analysis. The chemical structure of 2-allyl-6-((2-(dimethylamino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NI4) is shown in Scheme 2.…”

“…Derivatives of 1,8-naphthalimide have been increasingly investigated as a signaling unit in the design of sensor systems for the detection of cations, anions, or neutral analytes, which are major industrial environmental pollutants [12][13][14][15][16][17]. For the first time, we have combined the sensor activity of 1,8-naphthalimides with their ability to copolymerize with vinyl and methacrylate monomers to produce polymeric sensors [18].…”