Browsing by Author "Avinash Kumar Sonkar"
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PublicationArticle A benzimidazolyl terpyridine-Fe 2+ system and its recognition driven molecular model of a traffic light(Royal Society of Chemistry, 2019) Avinash Kumar Sonkar; Abhishek Rai; Kamini Tripathi; Pooja Sharma; H.W. Roesky; Michael G. B. Drew; Lallan MishraA new benzimidazolyl terpyridyl ligand (BIT) selectively detects Fe 2+ , F − and CN − ions in acetonitrile. The Fe 2+ complex [Fe(H-BIT) 2 ]·(ClO 4 ) 4 (1) displays the fast and selective detection of 2,4,6-trinitrophenol (TNP) with strong binding (log β = 8.51 ± 0.24) and a low limit of detection (1.4 × 10 −7 M) among several nitroaromatics. The color of complex 1 changes from purple to red, yellow, and green upon the separate addition of 2,4,6-trinitrophenol and tetrabutylammonium salts of fluoride and cyanide, respectively. The overall color changes thus display a model of a traffic light. The structures of BIT, 1 and [Fe(BIT) 2 ]·(TNP) 2 (2) have been well characterized using spectroscopic techniques and single crystal X-ray crystallography. © The Royal Society of Chemistry.PublicationArticle A dual optical probe with larger stokes shift for simultaneous detection of Cu2+ and Zn2+ ions and aggregation induced enhanced emission empowering selective detection of Cu2+ ions(Elsevier B.V., 2021) Avinash Kumar Sonkar; Abhishek Rai; Kamini Tripathi; Richa Yadav; Manjari Shukla; Brijesh Singh Chauhan; S. Srikrishna; Lallan MishraA new aggregation induced enhanced emission (AIEE) active probe (1) has been synthesized via single step condensation reaction of 2-amino-3-benzyloxypyridine with 3-allylsalicylaldehyde in methanol. Probe 1 has been fully characterized by various spectroscopic techniques i.e. IR, NMR (1H and 13C), HRMS and X-ray crystallography. 1 displays a large stokes shift of 190 nm. It recognizes Cu2+ ions colorimetrically and fluorescence intensity enhances on the addition of Zn2+ ions. 1 form nanoaggregates in H2O:CH3OH (80:20, v/v) which detects Cu2+ ions selectively. 1 in the presence of Zn2+ ions and its nanoaggregates n1 show switch on behaviour of green fluorescence comparable to mitochondrial membrane potential indicator, Mitotracker-Red, in larval gut tissues of Drosophila melanogaster. © 2020 Elsevier B.V.PublicationRetracted A multifunctional V-shape bis-hydrazone: Characterization, supramolecular architechtures, AIEE, recognition of cations (Cu 2+ , Zn 2+ ) and anions (HPO 4 2- and CN-), mechanochromism, computational and cell imaging studies(Elsevier B.V., 2018) Kamini Tripathi; Alok Kumar Singh; Avinash Kumar Sonkar; Anand Prakash; Jagat Kumar Roy; Lallan MishraA new bis-hydrazone (PYDS) obtained by the condensation of pyridine 2,6-di carbohydrazide with 4-diethylaminosalicylaldehyde in methanol, has been fully characterized using various physicochemical techniques, finally supported by its single crystal X-ray crystallography. X-ray analysis provides novel supramolecular architectures using π-π stacking and H-bonding interactions. It shows aggregation induced emission enhancement (AIEE) in DMF: H 2 O (50:50,v/v) and results the formation of nanoaggregates of 356 nm. These aggregates are characterized by SEM, TEM, AFM and DLS techniques. PYDS detects Cu 2+ and Zn 2+ ions in DMF: H 2 O (7:3, v/v) and displays a turn-on response in absorbance with a high degree of selectivity against common interfering cations. The Cu 2+ and Zn 2+ ions are also detected via chelation enhanced quenching (CHEQ) and chelation enhanced fluorescence (CHEF) processes respectively. DFT and TD-DFT calculations support the experimental results. PYDS enables the visualization of Cu 2+ and Zn 2+ in SiHa cell lines and it also quantify their detection in real water samples with a high precision and good accuracy. The PYDS-Zn 2+ and PYDS-Cu 2+ ensembles act as secondary sensors for HPO 4 2− and CN- anions respectively. The reversible changes in crystalline and amorphous structures of PYDS on applying a mechanical stress has been exploited in the construction of binary memory states. © 2018 Elsevier B.V.PublicationArticle A quick and selective rhodamine based “smart probe” for “signal-on” optical detection of Cu2+ and Al3+ in water, cell imaging, computational studies and solid state analysis(Elsevier B.V., 2018) Abhishek Rai; Alok Kumar Singh; Kamini Tripathi; Avinash Kumar Sonkar; Brijesh Singh Chauhan; S. Srikrishna; Tony D. James; Lallan MishraA novel rhodamine hydrazone 1 has been synthesized by the condensation of rhodamine B hydrazide with allylsalicylaldehyde and has been fully characterized using various physicochemical techniques including single crystal XRD. Probe 1 can detect Cu2+ and Al3+ ions in aqueous media and displays a turn-on response in absorbance with a high degree of selectivity amongst other common interfering analytes. Al3+ ions lead to fluorescence enhancementby the opening of the spirolactum ring resulting in chelation enhanced fluorescence. DFT and TDDFT calculations support the experimental results. The 1-Al3+ ensemble acts as secondary sensor for pyrophosphate anion due to metal ion induced decomplexation resulting in a low detection limit. Probe 1 can be utilized for bio imaging and displays morphological transformations from crystalline to amorphous state with associated color changes due to mechanical switching. In the solid state, probe 1 displays distinct color changes with emission at different wavelengths in particular Al3+ and Hg2+result in a red shift of the CIE-diagram. While the band gap of probe 1can be tuned from 2.08 eV to 1.60 eV Probe 1 meets many real-world-challenges in that it is prepared using simple synthetic methods, produces fast and distinct response towards multiple-ions, observed by the “naked eye” in solution and on a TLC plate, and can be exploited for binary data storage. © 2018 Elsevier B.V.PublicationArticle A smart switchable module for the detection of multiple ions: Via turn-on dual-optical readout and their cell imaging studies(Royal Society of Chemistry, 2016) Abhishek Rai; Alok Kumar Singh; Avinash Kumar Sonkar; Anand Prakash; Jagat Kumar Roy; Rajamani Nagarajan; Lallan MishraA module switchable as a function of multi-stimuli response has been designed. The module displays sequential logic gate-based detection of multiple ions (Fe3+, Hg2+, CN- and S2-) at ppm levels via a "turn on" signature which potentially meets real-world-challenges through a simple synthetic route, a fast response, water based-activity, naked-eye visualization, regenerative-action, high selectivity and multiple readout for precise analysis. Living cell imaging of Fe3+ and Hg2+ has also been carried out in HeLa cell lines. © 2016 The Royal Society of Chemistry.PublicationArticle A viscochromic, mechanochromic, and unsymmetrical azine for selective detection of Al3+ and Cu2+ ions and its mitotracking studies(Royal Society of Chemistry, 2019) Richa Yadav; Abhishek Rai; Avinash Kumar Sonkar; Vipin Rai; Subash Chandra Gupta; Lallan MishraA hydrazone obtained by the reaction of 2-hydroxynaphthaldehyde with hydrazine hydrate was allowed to react further with 4-diethylamino-2-hdroxybenzaldehyde to provide an unsymmetrical azine derivative (NDEA). The azine has been characterized using spectroscopic techniques and single crystal X-ray crystallography. It selectively detects Al3+ and Cu2+ ions in aqueous methanol (DMSO:H2O:MeOH = 0.1:1.9:8.0, v/v, HEPES buffer, pH 7.4) and exhibits naked eye visible color changes from greenish yellow to bright yellow and brown on the addition of Al3+ and Cu2+ ions, respectively, with concomitant changes in their absorption spectra. The corresponding solutions containing Al3+ and Cu2+ ions also display changes in their emission spectra via "TURN ON" and "TURN OFF" pathways with a detection limit of 1.65 × 10-7 M and 1.52 × 10-7 M, respectively. NDEA works as a reversible probe towards Al3+ ions and Cu2+ ions by the addition of F- ions and EDTA2- ions, respectively. The complexes of NDEA, separately with Al3+ and Cu2+ ions, have been optimized by DFT (density functional theory). It also exhibits viscochromic and mechanochromic properties. Most importantly, NDEA significantly detects these ions in rat C6 glioma cell lines and displays good cell permeability. It also co-localizes with the commercially available Mitotracker Red and exhibits a unique application as a live cell mitochondrial tracker. Practically, NDEA detects Al3+ and Cu2+ ions in real water samples and blood serum with a high accuracy. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.PublicationArticle An ensemble of Zn 2+ with a rhodamine B-3-allylsalicylaldehyde hydrazone as novel photosensitive material: Photochromism, photopatterning, photoprinting and molecular logic gates(Elsevier B.V., 2019) Abhishek Rai; Alok Kumar Singh; Avinash Kumar Sonkar; Kamini Tripathi; Lallan MishraAn ensemble of Zn 2+ with Rhodamine B-3-allylsalicylaldehyde hydrazone (1-Zn 2+ ), has been synthesized and fully characterized using spectroscopic techniques. A solution of 1-Zn 2+ in THF, displays color changes from light yellow to pink color in the presence UV light (λ, 405 nm). The process is reversible and owes to keto-enol tautomerism which allows the opening of spirolactam ring of rhodamine in the presence of UV light. It is corroborated by the appearance of a new peak at λ max = 554 nm. The ensemble, 1-Zn 2+ embedded in the matrix of silica gel, displays photo patterning phenomena initiated by the conventional light sources including sunlight. It also displays photoprinting property with a laser pen (λ 405 nm) and has been displayed by a videography. The module 1-Zn 2+ meets real challenges through a simple synthetic route, fast response, and as a binary data storage system with non-destructive optical identity. © 2019 Elsevier B.V.PublicationArticle Metalloreceptors of the type L-M-L [L = (4′-(2-pyridyl)-2,2′:6′,2″-terpyridine), M = Co(II), Cu(II), Zn(II)] for the recognition of Fe2+ ions(Elsevier Ltd, 2017) Priti Sinha; Avinash Kumar Sonkar; Kamini Tripathi; Niraj Kumari; Lallan MishraNew complexes of the type [Co(L)2](NO3)2 (P1), [Cu(L)2](NO3)2 (P2) and [Zn(L)2](NO3)2 (P3) where L = (4′-(2-pyridyl)-2,2′:6′,2″-terpyridine) have been synthesized and characterized using standard analytical and spectroscopic techniques (IR, 1H and 13C NMR, UV–Vis, fluorescence and ESR). The structures of the complexes were further authenticated by their single X-ray crystallography. The synthesized complexes are exploited as a receptor in the detection of cations using absorption and emission spectra, as well as cyclic voltammetry for P3 only. UV–Vis spectral titrations of each complex separately with Fe2+ ions displayed a new band at λmax = 570 nm. Among the complexes, only P3 emitted at room temperature at λemi = 450 nm. The intensity of the peak decreases on incremental addition of Fe2+ ions, with a concomitant appearance of a new peak at λemi = 525 nm. Distinct colour changes are observed in all three complexes in the presence of Fe2+ ions. Analytical detection limits using the standard deviation method are found as 1.2, 1.1 and 0.6 µM for complexes P1, P2 and P3 respectively. © 2017PublicationArticle Neuroprotective Activity of a Novel Synthetic Rhodamine-Based Hydrazone against Cu2+-Induced Alzheimer’s Disease in Drosophila(American Chemical Society, 2022) Brijesh Singh Chauhan; Abhishek Rai; Avinash Kumar Sonkar; Kamini Tripathi; Sonal Upadhyay; Lallan Mishra; Saripella SrikrishnaA new rhodamine-based probe 3,5-di-tert-butylsali-cylaldehyde rhodamine hydrazone (RHTB) has been synthesized and well characterized using spectroscopic techniques and single-crystal X-ray crystallography. Among several metal ions, it selectively detects Cu2+ ions as monitored by UV−Vis and emission spectral titrations. It displays “turn on” behavior owing to the opening of a spirolactum ring and the presence of 3,5-di-tert-butyl as an electron releasing group. Further, Cu2+ ions play a pivotal role in extracellular aggregation of Aβ42 peptides. So far, we know probably that there are no promising drugs available in this regard. Hence, countering the Cu2+ ions by RHTB chelation against orally administered Cu2+ ion-induced neurotoxicity in the eye tissue of Drosophila expressing human Aβ42 (amyloid-β42) has been tested. The present study involves in vivo and in silico approaches. They reveal the therapeutic potential of RHTB against Cu ion-induced Aβ42 toxicity in Alzheimer’s disease (AD) model of Drosophila. © 2022 American Chemical Society.PublicationErratum Retraction notice to: “A multifunctional V-shape bis-hydrazone: Characterization, supramolecular architechtures, AIEE, recognition of cations (Cu 2+ , Zn 2+ ) and anions (HPO 4 2- and CN-), mechanochromism, computational and cell imaging studies” (Sensors & Actuators: B. Chemical (2017) 245 (386–394), (S0925400517301739), (10.1016/j.snb.2017.01.166))(Elsevier B.V., 2019) Kamini Tripathi; Alok Kumar Singh; Avinash Kumar Sonkar; Anand Prakash; Jagat Kumar Roy; Lallan MishraThis article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor following concerns raised by a reader. The article uses several electron micrographs which have been used in other publications as well, denoting different samples. Fig. 1B is identical to Fig. 2A in Talanta vol 176, pp. 277-283 and Fig. 1A in Materials Letters vol. 195, pp. 131-135 while describing different samples. Fig. 1C appears to contain repeated particle clusters. Fig. 1D is identical to Fig. 2B in The Analyst, 2014, 139, 3398-3406 while describing different samples. Fig. 2 The overhang in the FT-IR spectra of carboxyl-modified CD2 at 1500 cm^-1 indicates that that the data has been manipulated. These problems with the data presented cast doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. © 2017 Elsevier B.V.PublicationErratum Retraction notice to: “A multifunctional V-Shape bis-hydrazone: Characterization, Supramolecular architechtures, AIEE, recognition of cations (Cu2+, Zn2+) and anions (HPO42- and CN-), mechanochromism, computational and cell imaging studies.” [Sensors and Actuators B: Chemical Volume 275, 1 December 2018, Pages 116-126](S0925400518314540)(10.1016/j.snb.2018.08.026)(Elsevier B.V., 2019) Kamini Tripathi; Alok Kumar Singh; Avinash Kumar Sonkar; Anand Prakash; Jagat Kumar Roy; Lallan MishraThis article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editors after an anonymous reader pointed out concern about the work. In Figure 4A and 4C duplicated particles were detected which the authors attributed to an accident. For Fig. 11 the authors provided the raw data but there is significant doubt that this data was used to prepare the figure as different samples show the same features in the images. For Fig. 10 and Fig. S33 the authors admitted the mistake of reusing the same panel. Given the deliberate readjustment of contrast and brightness, this appears to be an intentional action as reusing the same images should have led to the same results across the different percentages in Fig. S33. In Fig. 6 and Fig. S34 inconsistencies in the data have been raised which the authors failed to explain. After investigating and discussing these concerns with the authors, the Editors have reached the conclusion that the spread of fabricated data through the publication demonstrates an intent to modify the original data. The manipulation of images and data in this way casts doubts on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. © 2019 Elsevier B.V.PublicationArticle Selective Cu2+ Ion Sensing by Nanoaggregates of Pyridyl-2,6-bis(3-allylsalicylaldehyde)hydrazone(Wiley-Blackwell, 2018) Abhishek Rai; Kamini Tripathi; Avinash Kumar Sonkar; Tony D. James; Saurabh Yashaswee; Surendra Kumar Trigun; Lallan MishraPyridyl-2,6-bis(3-allylsalicylaldehyde) hydrazone (PYAL) forms nanoaggregates (nPYAL) in THF:water (10:90,v/v) with enhanced emission. The nanoagregates display selective and reversible detection of Cu2+ ions with concomitant changes in their morphology and sizes. The detection of Cu2+ ions in human melanoma MDA MB 435 s cell lines using nPYAL has been demonstrated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, WeinheimPublicationArticle Synthesis, photo-physical, computational and invitro cytotoxic studies of 4-((E)-2-benzylidenehydrazinyl)benzonitrile derivatives(Elsevier B.V., 2019) Kamini Tripathi; Abhishek Rai; Avinash Kumar Sonkar; Saurabh Yashaswee; Surendra Kumar Trigun; Lallan MishraHydrazones of type 4-((E)-2- benzylidenehydrazinyl)benzonitriles were obtained by the condensation of 4-cyanophenylhydrazine hydrochloride separately with 4-diethylaminosalicylaldehyde(M1), 5-nitrosalicylaldehyde(M2), 5-chlorosalicylaldehyde(M3), 2-hydroxylnaphthylaldehyde(M4), 2-acetylpyridine(M5) 2,6-diacetylpyridine(M6) and 2-methoxynaphthylaldehyde(M7) in methanol (Scheme 1). They were characterized using physico- chemical techniques and x-ray crystallography. Their absorption, emission spectra and fluorescence life time measured in solution as well as in the solid state, display the effect of substituents on their properties. All compounds except M2 and M3, display strong emission. The compounds, M1 and M6 exhibit in vitro cytotoxicity against MDA MB435 s (melanoma) with IC 50 values as 12 × 10 -5 , 1.3 × 10 -5 respectively. The compound, M1 also displays activity against C6 (glioma) with IC 50 value of 5.9 × 10 -5 M. © 2019