Ultrasensitive fluorescence detection of nitro-explosives by dihydro-oxoisobenzofuranyl-phthalazinone obtained from the Cd(ii)-catalyzed cyclization of azinodimethylidyne-benzoic acid. (5th April 2023)

• Record Type: Journal Article
• Authors: Singh, Durgesh; Chandra, Subhash; Pandey, Rampal
• Is Part Of: New journal of chemistry. Volume 47:Number 17(2023)
• Page Start: 8022
• Page End: 8031
• Publication Date: 2023-04-05
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj06277a
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Ultrasensitive detection of nitroexplosives is accomplished by utilizing the fluorescent probe dihydro-oxoisobenzofuranyl-phthalazinone obtained from the Cd(ii )-catalyzed cyclization of azinodimethylidyne-benzoic acid. Abstract : Chemical explosive detection through a feasible, straightforward, and efficient technique is essential for human safety. A Schiff base 2, 2′-(azinodimethylidyne)-bis-benzoic acid (2 ) was synthesized, characterized, and cyclized to form 2-(1, 3-dihydro-1-oxoisobenzofuran-3-yl)phthalazin-1(2 H )-one (1 ) upon treatment with various transition and lanthanide metal ions, especially with Cd(ii ). Further, the cyclized product 1 could act as a nanomolar sensitive fluorescent 'turn-off' probe for 2-nitrophenol ( o -NP, 86%) and picric acid (PA, 81%), wherein, the selectivity of 1 was higher for PA over o -NP. The fluorescence quenching of 1 in the presence of PA and o -NP may be attributed to the energy-transfer mechanism. The binding constants for o -NP and PA were in the order of 10 4 M −1, while the Stern–Volmer constants ( K sv ) were estimated to be in the order 10 5 . The limits of detection (LoDs) for 1 toward o -NP and PA were determined to be 4.52 ppb and 6.81 ppb, respectively, while the limits of quantification (LoQs) were determined to be 15.06 ppb and 22.69 ppb, respectively in DMF/H2 O. Probe 1 showed excellent selectivity toward o -NP and PA over a wide range of analytes, including cations, nitroaromatics, phenols, and aromatic amines. The present findings demonstrated that Cd(ii ) induced the rapid production of 1, which could serve as an ultrasensitive probe for o -NP and PA and was highly selective for PA with no interference of ions, nitro-explosives, phenols, or aromatic amines. The nitro-explosives o -NP and PA could also be determined in real Ganga river water samples using 1, which strongly suggest its possibility for practical applications.