Sensitive and Selective in Vitro Recognition of Biologically Toxic As(III) by Rhodamine Based Chemoreceptor

Abstract

Arsenic induced cleavage of the spirolactam ring of a cleft shaped electronically enriched rhodamine based chemoreceptor molecule 3′,6′-bis­(ethylamino)-2-((2-hydroxy-5-methylbenzylidene)­amino)-2′,7′-dimethylspiro­[isoindoline-1,9′-xanthen]-3-one (PBCMERI-23) has been reported in the present work. The developed easy, instant and economic luminescent probe instigate toward unlocking the selectivity for a specific lethal water contaminant such as As­(III) from aqueous media up to a level of 0.164 ppb (beyond the critical limit of the World Health Organization). PBCMERI-23 displays a 2-fold optical response (chromogenic, colorless to reddish pink; fluorogenic, non-blooming fluorescence to yellow emission) via the ring opening phenomenon of the developed chemoreceptor. Owing to the remarkable photophysical and structural properties of the synthesized probe, the recognition event has been turned on in the low energy region. Detailed experimental techniques further supported by theoretical evidence establishes the plausible mechanistic course of the host:guest interaction. The spectrophotometric response of the developed chemoreceptor PBCMERI-23 turns out to be reversible with incremental addition of a stoichiometric amount of I–. The optical recognition phenomenon has been further synchronized and interfaced with molecular logic gate to molecular electronics. To explicate the bioapplicability of PBCMERI-23, varying cell lines, viz., pollen grains of Allamanda puberula (Aapocynaceae), radiator plant (Peperomia pellucida), Poecilia reticulata, Danio rerio, and squamous epithelial cells have been monitored. The probe displays sparkling yellow illumination when the cells were visualized under fluorescence microscope, which confirms its cell permeability and is a biomarker toward intracellular investigation and bio-imaging of As­(III). Furthermore, the chemoreceptor has enormous capability in detecting As­(III) from a series of wastewater specimens with varying pH, which makes the present chemoreceptor PBCMERI-23 unique of its kind.

Unveiling of a smartphone-mediated ratiometric chemosensor towards the nanomolar level detection of lethal CN−: combined experimental and theoretical validation with the proposition of a molecular logic circuitry

“…The B3LYP hybrid functional and defSV(P)/defTZVP basis sets were used in the Turbomole (V7.0) software TmoleX interface, 4.1.1. 41 The experimental and simulated spectra (applying COSMO/acetonitrile) of DNMH and DNMH⋯CN − are shown in Fig. S21 † .…”

Colorimetric and fluorometric probes for the optical detection of environmental Hg(ii) and As(iii) ions

“…For both the sensors As(III) was bound through C=O and C=N segments as depicted in Sensor 83, [145] Condensation between rhodamine 6G hydrazide and 5-methyl salicylaldehyde produced sensor 84. [146] In acetonitrile: HEPES buffer An aggregation-induced emission-based sensor 85 was developed using tetraphenylethene (TPE) as a fluorescent moiety and cysteine as a binding ligand for As(III). [147] The aqueous solution (THF-water, 1:99, v/v) of 85 ( Figure 45) was nonfluorescent, but upon addition of As(III) an intense blue fluorescence was observed and it gradually became more intense with increasing concentration of As(III).…”

Zn2+ Recognition for Pathogenesis of Pick's Disease via a Luminescent Test Kit

“…L1 displayed four signals at 220, 250, 325 with a broad signal at 415 nm due to π-π*, n-π* and charge transfer transition within the framework respectively. The absorption spectra of L1 in acetonitrile: HEPES (4 : 1, v/v, conc n : 2 × 10 À 5 M, pH 7.4) [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] (λ max /nm; ε/M À 1 cm À 1 ): 325 (18100) and for L1-Zn 2 + (λ max /nm; ε/M À 1 cm À 1 ): 370 (11100) respectively (Figure S5a-b). Photoexcitation at 400 nm gives fluorescence of L1 (conc n : 5 × 10 À 6 M, pH 7.4) at 495 nm which reveals a Stokes Shift of 80 nm.…”