Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Mater Chem B ; 12(4): 1043-1051, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38214029

RESUMO

Coronene diimide functionalized with 4-(2-nitrovinyl)phenyl (CDI 2) serves as a precursor for generating a stable radical anion (CDI 2˙-) using H2S as a reductant in 40% H2O-THF solution in the NIR region with stability up to >50 min. The optical, cyclic voltammetry (CV), current-voltage (I-V) and electron paramagnetic resonance (EPR) studies revealed the formation of the radical anion (CDI 2˙-). The addition of a strong oxidant NOBF4 quenches the radical anion (CDI 2˙-). The aggregation studies revealed that CDI 2 exists in the aggregated state in 40% H2O-THF solution, which points to the possibility of stabilization of the radical anion in the aggregates. The radical anion (CDI 2˙-) was explored for the detection of 58.27 pM H2O2 in aqueous medium with the naked eye colour change from green to light yellow. The biochemical assay involving the radical anion (CDI 2˙-) and glucose oxidase (GOx) enzyme can be used for the detection of 16 pM (UV-vis method) and 82.4 pM (fluorescence method) glucose. The naked eye colour change from green to light yellow (daylight) and a colorless non-fluorescent solution to a green fluorescent solution (365 nm) allow the detection of 1 nM glucose.


Assuntos
Glucose , Peróxido de Hidrogênio , Compostos Policíclicos , Ânions , Espectroscopia de Ressonância de Spin Eletrônica
2.
Chem Commun (Camb) ; 59(100): 14843-14846, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38015427

RESUMO

The formation of radical anions (PDI 1˙-) using H2S as a sacrificial electron donor in 50% HEPES buffer-THF solution is reported. PDI 1˙- was confirmed by optical, I-V plot, CV, DPV, NOBF4 and EPR studies. PDI 1˙- has a half-life of 96 minutes in solution and 11 days in the solid state without any additive. The formation of PDI 1˙- was confirmed by AFM and SEM. PDI 1˙- can be used for the detection of 26.6 pM of H2O2 supported by optical and CV data.

3.
Anal Methods ; 15(38): 5010-5017, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37728434

RESUMO

A naphthalimide based chemosensor (NPG), containing 1,8-naphthalimide as a fluorophore unit and pentaethylene glycol as a binding unit, has been used for the detection of Pd2+ ions in 50% HEPES buffer-DMSO (pH 7.2) solution. The NPG showed aggregation induced emission enhancement (AIEE) properties in H2O-DMSO binary mixtures (0-90%) and the CIE plot of NPG in DMSO has x = 0.152, y = 0.102 coordinates corresponding to blue colour emission with 86% colour purity. Upon addition of Pd2+ ions, NPG showed a decrease in fluorescence intensity associated with a colour change from fluorescent blue to non-fluorescent colourless solution. The lowest limit of detection for Pd2+ ions was 75 nM. The mechanism of interaction of NPG with Pd2+ ions leads to complexation induced aggregation caused quenching (ACQ) supported by DLS, SEM and AFM studies. The NPG has been successfully utilized for (i) intracellular detection of Pd2+ ions (250 µM) in live MG-63 cells; (ii) detection of Pd2+ ions in pharmaceutical (99.74 ± 0.6%), urine (98.20 ± 2.96%) and blood serum (99.17 ± 1.84%) samples and (iii) detection of Pd2+ ions using silica coated TLC strips via a contact mode method. NPG can be used as a security ink for writing letters and alphabets for anticounterfeiting applications.

4.
Anal Methods ; 15(19): 2391-2398, 2023 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-37139593

RESUMO

In this report, we present our results on the recognition of multiple analytes using trisubstituted PDI-based chemosensors DNP and DNB in 50% HEPES buffered-CH3CN solution. Upon the addition of Hg2+, DNB showed a decrease and increase in absorbance intensity at 560 and 590 nm, respectively, with a detection limit of 7.17 µM and bleaching of the violet color (de-butynoxy). Similarly, the addition of Fe2+ or H2S to the solution of DNP or DNB resulted in ratiometric changes (A688nm/A560nm) with respective detection limits of 185 nM and 27.6 nM for Fe2+, respectively, and a color change from violet to green. However, the addition of >37 µM H2S caused a decrease in absorbance at 688 nm with a concomitant blue shift to 634 nm. Upon the addition of dopamine, the DNP + Fe2+ assay showed ratiometric (A560nm/A688nm) changes within 10 s along with a color change from green to violet. Moreover, DNP has been successfully used for the exogenous detection of Fe2+ in A549 cells. Further, the multiple outputs observed with DNP in the presence of H2S have been used to construct NOR, XOR, INH and 4-to-2 encoder logic gates and circuits.


Assuntos
Mercúrio , Perileno , Corantes Fluorescentes , Dopamina
5.
ACS Omega ; 8(2): 2639-2647, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36687064

RESUMO

The limitations of prevailing probes for the detection of human serum albumin (HSA) and HSO3 - make it challenging to apprehend the cooperative effect of both HSA and HSO3 - in biological systems. Herein, we present a multi-responsive fluorescent probe MGTP, which distinguishes HSA from bovine serum albumin (BSA) through an ∼104-fold fluorescence enhancement at an emission maximum of 595 nm with HSA and only an ∼10-fold increase at an emission maximum of 615 nm with a shoulder at 680 nm with BSA. The absorbance spectrum of MGTP also discriminates HSA and BSA with the respective absorption maxima at 543 nm and at 580 nm. MGTP in the confined space of HSA or BSA undergoes instantaneous conjugate addition of HSO3 - and results in a ratiometric change in fluorescence intensity with diminishing of red fluorescence (600 nm) and emergence of green fluorescence (515 nm). MGTP in the absence of SAs does not react with HSO3 - in phosphate-buffered saline buffer and reacts sluggishly in the dimethyl sulfoxide-water 1:1 mixture. The limit of detection values for the detection of HSA and HSO3 - are 4 and 6.88 nM, respectively. The drug binding studies reveal that MGTP preferably confines itself at the bilirubin site of HSA. In MCF-7 cancer cells, MGTP is localized into mitochondria and reveals both exogenous and endogenous visualization of HSO3 - through a change in fluorescence from the red to green channel.

6.
Anal Methods ; 15(2): 203-211, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36520082

RESUMO

We have developed a new naphthalimide-based amphiphile (YN-1) for the simultaneous detection of ATP and CTP. In YN-1, the cationic tyrosine-linked polyamine (+2 charge, hydrophilic unit) is appended at the -peri position of naphthalimide (hydrophobic unit). YN-1 and its Boc-protected compound 4 were characterized using state-of-the-art spectroscopic and optical techniques such as NMR, IR, UV-vis and fluorescence. The fluorescence data revealed that YN-1 showed a 'turn-on' (λem = 440 nm) fluorescence response for nanomolar detection of nucleoside triphosphates such as ATP and CTP in 20% HEPES buffer-DMSO solution. YN-1 also showed a concentration-based discrimination between ATP and CTP. YN-1 has been successfully applied for bioimaging of nucleoside triphosphates in MCF-7 live cancer cells with good compatibility. Therefore, the important findings from the present work will provide insight for future development of fluorescent probes to detect various kinds of essential nucleoside triphosphates.


Assuntos
Naftalimidas , Nucleosídeos , Corantes Fluorescentes/química , Trifosfato de Adenosina
7.
Molecules ; 27(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36431779

RESUMO

Here, in the present work, a new hydroxybenzothiazole derivative (HBT 2) with AIE+ESIPT features was synthesized by Suzuki-Miyora coupling of HBT 1 with 4-formylphenylboronic acid. The AIE and ESIPT features were confirmed by optical, microscopic (AFM) and dynamic light scattering (DLS) techniques. The yellow fluorescent aggregates of HBT 2 can specifically detect Cu2+/Cu+ ions with limits of detection as low as 250 nM and 69 nM. The Job's plot revealed the formation of a 1:1 complex. The Cu2+ complexation was further confirmed by optical, NMR, AFM and DLS techniques. HBT 2 was also used for the detection of Cu2+ ions in real water samples collected from different regions of Punjab. HBT 2 was successfully used for the bio-imaging of Cu2+ ions in live A549 and its anticancer activity was checked on different cancer cell lines, such as MG63, and HeLa, and normal cell lines such as L929. We successfully utilized HBT 2 to develop security labels for anticounterfeiting applications.


Assuntos
Corantes Fluorescentes , Humanos , Corantes Fluorescentes/química , Células HeLa
8.
Bioorg Chem ; 129: 106169, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36174442

RESUMO

The F- ion and viscosity both affect the physiological state of mitochondria and to the best of our knowledge no fluorescent probe is reported for the dual detection of mitochondrial viscosity and F- ion through different signals. DMAS-Si is weakly red fluorescent due to free intramolecular rotation between dimethylaminophenyl and pyridinium moieties and PET from silyloxy to the pyridinium moiety. In viscous medium (glycerol 90 %), the rotation is restricted and 18-fold increase in red-fluorescence (λem 637 nm) is observed. On reaction with F- ion, the desilylations followed by release of quinone-methide from DMAS-Si gives intense green fluorescence (λem 515 nm) due to formation of DMAS. DMAS-Si can detect as low as 50 nM F-. DMAS-Si shows good permeability to HeLa cells and preferably targets mitochondria. It has been used for imaging of increased viscosity in mitochondria of HeLa cells in the presence of nystatin through red fluorescence and exogenous F- ion by appearance of green fluorescence.


Assuntos
Corantes Fluorescentes , Mitocôndrias , Humanos , Viscosidade , Células HeLa , Imagem Óptica/métodos
9.
AAPS PharmSciTech ; 23(6): 209, 2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35902454

RESUMO

The present study is focused on the use of solid dispersion technology to triumph over the solubility-related problems of bexarotene which is currently used for treating various types of cancer and has shown potential inhibitory action on COVID-19 main protease and human ACE2 receptors. It is based on comparison of green locust bean gum and synthetic poloxamer as polymers using extensive mechanistic methods to explore the mechanism behind solubility enhancement and to find suitable concentration of drug to polymer ratio to prepare porous 3rd generation solid dispersion. The prepared solid dispersions were characterized using different studies like X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), differential scanning calorimetry (DSC), and particle size analysis in order to determine the exact changes occurred in the product which are responsible for enhancing solubility profiles of an insoluble drug. The results showed different profiles for particle size, solubility, dissolution rate, porosity, BET, and Langmuir specific surface area of prepared solid dispersions by using different polymers. In addition to the comparison of polymers, the BET analysis deeply explored the changes occurred in all dispersions when the concentration of polymer was increased. The optimized solid dispersion prepared with MLBG using lyophilization technique showed reduced particle size of 745.7±4.4 nm, utmost solubility of 63.97%, pore size of 211.597 Å, BET and Langmuir specific surface area of 5.6413 m2/g and 8.2757 m2/g, respectively.


Assuntos
COVID-19 , Química Farmacêutica , Adsorção , Varredura Diferencial de Calorimetria , Química Farmacêutica/métodos , Humanos , Microscopia Eletrônica de Varredura , Polímeros/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
10.
J Mater Chem B ; 10(1): 107-119, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34889936

RESUMO

Positively charged amphiphiles hold great significance in supramolecular chemistry due to their good solubility, and physiochemical and molecular recognition properties. Herein, we report the synthesis, characterization and molecular recognition properties of the dicationic amphiphile based on perylene diimide-tyrosine alkyl amide amine (PDI 3). PDI 3 showed the formation of a nanoring architecture in the self-assembled aggregated state (90% H2O-DMSO mixture) as observed by SEM and TEM studies. The diameter of the nanoring is around 30-50 nm with a height varying from 1 to 2 nm. The self-assembled aggregates of PDI 3 are very sensitive towards nucleoside triphosphates. Upon addition of ATP, PDI 3 showed a decrease in the absorbance and emission intensity at 535 and 580 nm (due to the monomer state), respectively. The lowest detection limit for ATP is 10.8 nM (UV) and 3.06 nM (FI). Upon interaction of ATP with PDI 3, the nanoring morphology transformed into a spherical structure. These changes could be attributed to the formation of ionic self-assembled aggregates between dicationic PDI 3 and negatively charged ATP via electrostatic and H-bonding interactions. The complexation mechanism of PDI 3 and ATP was confirmed by optical, NMR, Job's plot, DLS, SEM and AFM studies. PDI 3 displays low cytotoxicity toward MG-63 cells and can be successfully used for the detection of exogenous and endogenous ATP. The resulting PDI 3 + ATP complex is successfully used as a 'turn-on' biochemical assay for monitoring phosphorylation of glucose.


Assuntos
Trifosfato de Adenosina/análise , Materiais Biocompatíveis/química , Glucose/análise , Imidas/química , Nanopartículas/química , Perileno/análogos & derivados , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Glucose/metabolismo , Humanos , Imidas/síntese química , Imidas/farmacologia , Teste de Materiais , Tamanho da Partícula , Perileno/síntese química , Perileno/química , Perileno/farmacologia , Fosforilação , Células Tumorais Cultivadas
11.
J Cardiovasc Electrophysiol ; 32(11): 3027-3034, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34554620

RESUMO

INTRODUCTION: Defibrillation testing (DT) is recommended during the subcutaneous defibrillator (S-ICD) placement. We sought to compare 10 J shock impedance in sinus rhythm (SR) with 65 J defibrillation impedance and evaluate device position on a postimplant chest X-ray (CXR) using an intermuscular (IM) technique. METHODS: Consecutive S-ICD implantations between 12/2019 and 12/2020 at The Ohio State University were reviewed. All implantations were performed using a two-incision IM technique. Standard DT with 65 J shock and 10 J shock in SR were performed unless contraindicated. The PRAETORIAN score was calculated based on CXR. RESULTS: A total of 37 patients (age: 47.2 ± 15.8 years old, male: n = 26 [70.3%], body mass index: 30.1 ± 6.7 kg/m2 ) underwent IM S-ICD implantation, and of those, 27 (73%) underwent both 65 J shock and 10 J shock in SR. The coefficient of determination (R2 ) between 10 J shock impedance and 65 J shock impedance was 0.84. The mean of an impedance difference was 1.6 ± 4.8 Ω (minimum - 11 and maximum 8). Postimplant CXR was available for 33 out of 37 patients (89.2%). The PRAETORIAN score was less than 90 in all patients and the mean score was 32.7 ± 8.8. CONCLUSION: We demonstrated that 10 J shock impedance in SR correlated well with 65 J defibrillation impedance during IM S-ICD implantation. An IM implantation technique provides excellent generator location on postimplant CXR. The IM technique combined with 10 J shock in SR may be sufficient to predict and ensure the defibrillation efficacy of the S-ICD.


Assuntos
Desfibriladores Implantáveis , Adulto , Arritmias Cardíacas , Cardioversão Elétrica , Impedância Elétrica , Humanos , Masculino , Pessoa de Meia-Idade , Ohio , Tela Subcutânea
12.
Luminescence ; 36(3): 802-811, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33386700

RESUMO

Multipodand conjugates were designed and synthesized and incorporated 5-chloro-8-hydroxyquinoline for efficient performance and fine tuning to behave as molecular switches by the addition of metals ions, protonation, and their combination in CH3 CN and CH3 CN-H2 O. Dipodand 3 and tetrapodand 4 showed a switching 'ON' of fluorescence (λem = 435-445) with Zn2+ and Cd2+ (OR logic) and switching 'OFF' of fluorescence (λem = 402) in the presence of Cu2+ , Co2+ and Ni2+ (NOR logic). 4 showed switching 'OFF' of fluorescence at 402 nm at low concentrations of Ag+ , Pb2+ , Hg2+ and Fe3+ and, on further accumulation of these metal ions, excimer bands at 432 nm (Ag+ ) and 510 nm (Pb2+ , Hg2+ and Fe3+ ) provided the opportunity for 'ON-OFF-ON' switching. In contrast, 3 showed no change with Ag+ , while Pb2+ caused only 'ON-OFF' switching and Hg2+ and Fe3+ ions caused similar 'ON-OFF-ON' switching. The H+ -induced 'ON-OFF-ON' molecular switch was combined with Cu2+ that persuaded NOR logic to mimic inhibit (INH) logic. The compound also exhibited a H+ /Cu2+ -induced 'OFF-ON-OFF' type of signalling pattern. These proton-induced multiple outputs provide opportunities for YES, NOT logic gates. 3 showed selective 'ON-OFF' behaviour with Fe3+ ions and 'OFF-ON' behaviour with Cd2+ ions in 20% HEPES buffer-CH3 CN.


Assuntos
Cádmio , Mercúrio , Íons , Metais , Prótons
13.
RSC Adv ; 11(10): 5860-5864, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35423115

RESUMO

We report an NIR-based photoluminescent material, namely benzo-coronene diimide (CDI 2), and its use in the visualization of latent fingerprints (LFPs) and in the metal ion detection in an aqueous medium. CDI 2 exhibited nano-sized interlinked fibre structures forming 'bowl' shaped nanoarchitectures as red emitters with the Commission Internationale de l'Eclairage (CIE) coordinates (x, y) of (0.67, 0.33) with 100% colour purity in the solid state. CDI 2 was confirmed to be the potential candidate for the analysis of LFPs and the detection of Pd2+/Cu2+ in an aqueous medium.

14.
Pacing Clin Electrophysiol ; 43(12): 1451-1458, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32926443

RESUMO

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an important tool in the armamentarium of an electrophysiologist. Multiple randomized trials over the last decade have shown that S-ICDs are as efficacious as the transvenous ICDs and eliminate complications related to vascular access. In this review, we highlight issues unique to S-ICD implantation, focusing not only on the surgical implantation procedure, but also the pre- and postimplant management of the patient.


Assuntos
Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis , Algoritmos , Análise de Falha de Equipamento , Humanos , Seleção de Pacientes
15.
Anal Methods ; 12(28): 3560-3574, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32701085

RESUMO

Perylene diimides (PDI) are a well-studied class of functional organic dyes, and in recent years, they have been accepted as promising scaffolds for the design of small molecule/polymer-based chromogenic and fluorogenic reaction-based-probes because of their strong absorption combined with high fluorescence quantum yield in organic solvents, low reduction potential, good electron-acceptor properties, and broad color range properties. Undoubtedly, the intrinsically poor solubility of PDI-based derivatives in water greatly hampers their exploitation as reaction-based probes; however, a vast array of functionalizations now offer design strategies that have resulted in >50% solubility of PDI derivatives in water. A chemodosimeter, wherein chemical transformation is achieved by specific reactions, affords naked-eye visibility, fast response time, sensitivity, ratiometric response, and low cost. The present review focuses on the progress of PDI-based chemodosimeters achieved so far since the inception of this member in the rylene diimide family. This comprehensive review may facilitate the development of more powerful chemodosimeters based on PDI for broad and exciting applications in the future.

16.
Photochem Photobiol Sci ; 19(4): 504-514, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32236245

RESUMO

A near-IR perylene diimide probe (OPR-PDI) containing an oxime-propargyl hybrid moiety at the bay position, was designed and synthesized for detection of Pd species and Cu2+ ions in 90% water, the solid state and MG-63 live cells. The aggregation tendency of OPR-PDI in different polarity solvents transmits solvatochromic and fluorochromic properties to differentiate certain organic solvents. Supramolecular aggregates of OPR-PDI in 90% water act as a dual chemosensor for palladium (Pd) species via de-propargylation or hydrolysis of the Schiff-base and Cu2+ ions via complexation with the O/N binding site with a low limit of detection (LOD) of the order of 7.9 × 10-8 M and 3.4 × 10-7 M respectively. TLC strips coated with OPR-PDI can be applied for sensing of Pd0 and Cu2+ ions in the solid state at levels as low as 34.6 ng cm-2 and 10.5 ng cm-2. OPR-PDI imprinted TLC strips could be used as paper sheets for writing coloured alphabets using Pd0 and Cu2+ ions as ink. Moreover, MTT assay showed that OPR-PDI has very low cytotoxicity (IC50 = 230 µM), good permeability, biocompatibility and can be applied for bio-imaging of Pd species and Cu2+ ions in MG-63 cells. DFT calculations, and cyclic voltammetric (CV) and NMR titration studies have also been discussed.


Assuntos
Cobre/análise , Corantes Fluorescentes/química , Imidas/química , Chumbo/análise , Oximas/química , Perileno/análogos & derivados , Poluentes Químicos da Água/química , Teoria da Densidade Funcional , Técnicas Eletroquímicas , Corantes Fluorescentes/síntese química , Humanos , Imidas/síntese química , Raios Infravermelhos , Íons/análise , Microscopia Confocal , Estrutura Molecular , Perileno/síntese química , Perileno/química , Células Tumorais Cultivadas
17.
Antioxidants (Basel) ; 9(2)2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32093300

RESUMO

: Cassia fistula L. is a highly admirable traditional medicinal plant used for the treatment of various diseases and disorders. The present study was performed to divulge the antioxidant, antiproliferative, and apoptosis-inducing efficacy of fractions from C. fistula leaves. The hexane (CaLH fraction), chloroform (CaLC fraction), ethyl acetate (CaLE fraction), n-butanol (CaLB fraction), and aqueous (CaLA fraction) were sequentially fractionated from 80% methanolic (CaLM extract) of C. fistula leaves. The CaLE fraction was fractionated using column chromatography to yield a pure compound, which was characterized as Epiafzelechin (CFL1) based on 1H, 13C, and DEPT135 NMR. Among these fractions, CaLE and isolated CFL1 fractions exhibited an effective antioxidant potential in Ferric ion reducing power, (2,2'-azino-bis (3-ethylbenzothiazoline -6-sulfonic acid)) cation radical scavenging, and nitric oxide radical scavenging assays. Epiafzelechin was investigated for its antiproliferative effects against MG-63 (osteosarcoma), IMR-32 (neuroblastoma), and PC-3 (prostate adenocarcinoma), and was found to inhibit cell proliferation with a GI50 value of 8.73, 9.15, and 11.8 µM respectively. MG-63 cells underwent apoptotic cell death on treatment with Epiafzelechin as the cells showed the formation of apoptotic bodies, enhanced reactive oxygen species (ROS) generation, mitochondrial membrane depolarization along with an increase in early apoptotic cell population analyzed using Annexin V-FITC/PI double staining assay. Cells showed cell cycle arrest at the G0/G1 phase accompanied by a downregulation in the expression levels of p-Akt (Protein kinase B), p-GSK-3ß (Glycogen synthase kinase-3 beta), and Bcl-xl (B-cell lymphoma-extra large) proteins. RT-PCR (Real time-polymerase chain reaction) analysis revealed downregulation in the gene expression level of ß-catenin and CDK2 (cyclin-dependent kinases-2) while it upregulated the expression level of caspase-8 and p53 genes in MG-63 cells.

18.
J Mater Chem B ; 8(1): 125-135, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31777906

RESUMO

A fluorescent probe PDI-DAMN based on perylenediimide containing diaminomaleonitrile at the bay-position was designed and synthesized for the detection of ClO-. PDI-DAMN self-assembled as nanofibers with diameters in the range of 100-200 nm in H2O : CH3CN (1 : 1). The addition of ClO- into PDI-DAMN resulted in the disintegration of nanofibers into flake-like aggregates of smaller size (50-80 nm) as supported by SEM and DLS data. The addition of ClO- to HEPES buffer-CH3CN solution (1 : 1, v/v, pH 7.4) of PDI-DAMN caused a hypochromic effect on the ICT band at 528 nm and 'turn-on' fluorescence enhancement at 508/554 nm due to the oxidative cleavage of -C[double bond, length as m-dash]N- bond. A linear correlation plot between the concentration of ClO-versus fluorescence intensity (R2 = 0.9968)/absorbance (R2 = 0.9988) in the concentration range 0-7 nM (fluorescence)/0-90 nM (absorbance) could determine ClO- with the detection limits of 1 and 10 nM, respectively. Optical studies performed on spiked urine and blood serum samples showed good estimation and recovery of ClO- (100 ± 5%). TLC-based test-strips coated with PDI-DAMN changed colour upon the addition of ClO- with detection as low as 7.44 ng cm-2. The application of PDI-DAMN for the bio-imaging of both exogenous and endogenous ClO- in MG-63 cells with good biocompatibility has also been demonstrated. The detailed mechanism of the interactions of ClO- with PDI-DAMN using 1H NMR titration, DFT studies and response mechanism of pH are also discussed.


Assuntos
Fluorescência , Ácido Hipocloroso/análise , Nanofibras , Água/química , Análise Química do Sangue , Linhagem Celular , Humanos , Imidas/química , Nitrilas/química , Perileno/análogos & derivados , Perileno/química , Urina/química
19.
J Mater Chem B ; 7(45): 7218-7227, 2019 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-31663586

RESUMO

The sustainable development of point-of-care testing (POCT) for spermine detection is important to check for food spoilage, early diagnosis of various malignancies and diminished anticonvulsant drug carbamazepine response in chronic epilepsy. Herein, the synthesis, characterization and spectroscopic properties of perylene diimide EA-PDI∩Cu2+ complex based nanoparticles towards spermine were studied in detail. This EA-PDI∩Cu2+ complex can be used for the ultrasensitive detection of spermine as low as 86.3 nM (UV-vis) and 90 pM (fluorescence) in aqueous medium, in urine and blood serum samples (recovery 99 ± 3) and in the solid state (0.1 µg L-1), and EA-PDI shows minimal cytotoxicity to cells and can easily enter into Human Osteosarcoma MG-63 cells for bio-imaging of Cu2+ and spermine. This EA-PDI∩Cu2+ complex can be established as a cost-effective method to develop a diagnostic kit for POCT of spermine in terms of a solution-based test kit for real time detection of spermine in vapor and solution form released from fermented food samples.


Assuntos
Cobre/química , Corantes Fluorescentes/química , Contaminação de Alimentos/análise , Imidas/química , Nanopartículas/química , Perileno/análogos & derivados , Testes Imediatos , Kit de Reagentes para Diagnóstico , Espermina/análise , Corantes Fluorescentes/síntese química , Humanos , Tamanho da Partícula , Perileno/química , Propriedades de Superfície
20.
RSC Adv ; 9(44): 25554-25568, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-35530050

RESUMO

The [6 + 2] cycloaddition reactions are one of the important synthetic transformations to construct eight membered carbo-/heterocyclic systems. The present review is an attempt to update readers on transition metal catalyzed [6 + 2] cycloaddition reactions of various 6π-contributing substrates such as cycloheptatrienes (CHT), cyclooctatetrenes (COTT), allenals, vinylcyclobutanones, fulvene etc. employing rhodium, cobalt, titanium, copper, platinum, ruthenium, rhenium and diphenylprolinolsilyl ethers etc. as catalysts. The transition metal catalyzed [6 + 2] cycloaddition reactions with a variety of functionalized substrates provide straightforward access to eight membered cyclic and/or 5/8, 6/8 etc. condensed carbo-/heterocyclic molecules in moderate to good yields.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA