scholarly journals Nanostructure-enhanced infrared spectroscopy

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Takuo Tanaka ◽  
Taka-aki Yano ◽  
Ryo Kato

Abstract While infrared spectroscopy is a powerful technique that provides molecular information such as chemical constituents and chemical structures of analytes, it suffers from low absorption cross-section resulting in low sensitivity and poor signal-to-noise or signal-to-background ratios. Surface-enhanced infrared absorption (SEIRA) spectroscopy, which is supported by nanometer scale structures, is a promising technology to overcome these problems in conventional infrared (IR) spectroscopy and enhances IR signals using the field enhancement properties of surface plasmon resonance. Recently resonant SEIRA technique was proposed, and signal enhancement factor was significantly improved. In this review, we present an overview of the recent progresses on resonant SEIRA technologies including nanoantenna- and metamaterial-based SEIRA, and also SEIRA techniques with nanoimaging capabilities.

Author(s):  
Subbiah Latha ◽  
Palanisamy Selvamani ◽  
Thangavelu Prabha

: Natural products have a unique place in the healthcare industry. The genus Commiphora emerged as a potential medicinal with huge benefits as evidenced through its use in various traditional and modern systems of medicine. Therefore, we aimed to prepare a concise review on the pharmacological activities and the indigenous uses of various plant species belonging to the genus Commiphora along with the structural information of various active botanical ingredients present in these plants based on the published literatures and scientific reports. To collect the various published literatures on Commiphora in various journals; to study and classify the available information on the pharmacological uses and chemical constituents; and to present the gathered information as a precise review to serve as a potential reference for future research. Pharmacological and phytochemical data on Commiphora plant species were collected from various journals, books, reference materials, websites including scientific databases, etc for compilation. This review article describes the various pharmacological properties of plants of Commiphora species viz., Anti-arthritic and anti-inflammatory, Anti-atherogenic, Antibacterial, Anti-coagulant, Anti-dicrocoeliasis, Anti-epileptic, Anti-fascioliasis, Anti-fungal, Anti-heterophyidiasis, Anti-hyper cholesterolemic, Anti-hyperlipidemic, Anti-hypothyroidism, Anti-obesity, Anti-osteoarthritic, Anti-osteoclastogenesis, Anti-oxidant, Anti-parasitic, Anti-pyretic, Anti-schistosomiasis, Anti-septic, Anti-thrombotic, Anti-ulcer, Cardioprotective, COX enzyme inhibitory, Cytotoxic /Anti-carcinogenic/Anti-cancer, DNA cleavage, Hypotensive, Inhibits lipid peroxidation, Inhibits NO and NO synthase production, Insecticidal, Local anesthetic, Molluscicidal, Smooth muscle relaxant, Tick repellent activities along with toxicity studies. Furthermore, the review also included various secondary metabolites isolated from various species of Commiphora genus along with their chemical structures serve as a ready resource for researchers. We conclude that the plant species belonging to the genus Commiphora possesses abundant pharmacological properties with a huge treasure of diverse secondary metabolites within themselves. This review indicates the necessity of further in-depth research, pre-clinical and clinical studies with Commiphora genus which may help to detect the unidentified potential of the Commiphora plant species.


2020 ◽  
Vol 23 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Mohammad Musarraf Hussain

Erythrina is a significant source of phytoconstituents. The aim of this review is to solicitude of classification, synthesis, and phytochemicals with biological activities of Erythrina. In our previous review on this genus (Hussain et. al., 2016a) fifteen species (Erythrina addisoniae, E. caribeae, E. indica, E. lattisima, E. melanacantha, E. mildbraedii, E. poeppigiama, E. stricta, E. subumbrans, E. veriagata, E. vespertilio, E. velutina, E. zeberi, E. zeyheri and E. americana) have been studied and 155 molecules with chemical structures were reported. A further comprehensive review was done upon continuation on the same genus and thirteen species (E. abyssinica, E. arborescens, E. berteroana, E. burttii, E. caffra, E. coralloids, E. crista-galli, E. fusca, E. herbaceae, E. lysistemon, E. mulungu, E. speciosa and E. tahitensis) of Erythrina have been studied and 127 compounds are reported as phytoconstituents with their chemical structure in this review. Erythrina crista-galli and E. lysistemon consist of highest number of chemical constituents. Bangladesh Pharmaceutical Journal 23(1): 65-77, 2020


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bao-xin Yan ◽  
Yan-ying Zhu ◽  
Yong Wei ◽  
Huan Pei

AbstractIn this paper, the surface enhanced Raman scattering (SERS) characteristics of Au and Au@Al2O3 nanoparticle dimers were calculated and analyzed by using finite element method (3D-FEM). Firstly, the electric field enhancement factors of Au nanoparticles at the dimer gap were optimized from three aspects: the incident angle of the incident light, the radius of nanoparticle and the distance of the dimer. Then, aluminum oxide is wrapped on the Au dimer. What is different from the previous simulation is that Al2O3 shell and Au core are regarded as a whole and the total radius of Au@Al2O3 dimer is controlled to remain unchanged. By comparing the distance of Au nucleus between Au and Au@Al2O3 dimer, it is found that the electric field enhancement factor of Au@Al2O3 dimer is much greater than that of Au dimer with the increase of Al2O3 thickness. The peak of electric field of Au@Al2O3 dimer moves towards the middle of the resonance peak of the two materials, and it is more concentrated than that of the Au dimer. The maximum electric field enhancement factor 583 is reached at the shell thickness of 1 nm. Our results provide a theoretical reference for the design of SERS substrate and the extension of the research scope.


Author(s):  
Dung Thi Kim Le ◽  
Hao Xuan Bui ◽  
Tuyet Thi Anh Nguyen ◽  
Tuyen Nguyen Kim Pham ◽  
Huy Thuc Duong

Euphorbia tirucalli has not been chemically studied much in Vietnam. This research described the isolation and elucidation of compounds isolated from the plant collected in Binh Thuan. Multiple chromatographic methods were applied, including normal phase silica gel column chromatography and thin-layer chromatography. Seven compounds were isolated and their chemical structures were elucidated by spectroscopic analysis as well as comparing their data with the ones in the literature. They are arjunolic acid (1), eriodictyol (2), quercitrin (3), afzelin (4), scopoletin (5), 3,3′,4- trimethylellagic acid (6), and gallic acid (7). Among them, compound 1 a major component was isolated for the first time in Euphorbia genus, while three compounds 2, 4, and 5 were isolated from this species for the first time.


2019 ◽  
Vol 57 (2) ◽  
pp. 162
Author(s):  
Quan Minh Pham ◽  
Hoai Van Thi Tran ◽  
Lam Tien Do ◽  
Phuong Lan Doan ◽  
Inh Thi Cam ◽  
...  

Urena lobata L. is used in Vietnamese traditional medicine for the treatment of several diseases. Tree roots are used to treat rheumatism, dysentery, poor digestion, flu, tonsils, malaria, asthma, goiter. Flowers are used to treat chickenpox, fever, and mental disorders. Branches, leaves or whole trees used to treat injuries bruises, rheumatism, mastitis, bites. Phytochemical investigation of the n-hexan and ethyl acetate extract of Urena lobata L. led to the isolation of β-sitosterol (1), β-sitosterol-3-O-β-D-glucopyranoside (2), a-acetylamino-phenylpropyl a-benzoylamino-phenylpropanoate (3), quercetin (4), and trans-tiliroside (5). Their chemical structures were determined by spectroscopic methods including MS, 1D, 2D NMR and comparing with those reported in previous papers. Two compounds 3, 5 were isolated for the first time from Urena lobata plant.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 62
Author(s):  
Fatima Omeis ◽  
Zahia Boubegtiten-Fezoua ◽  
Ana Filipa Santos Seica ◽  
Romain Bernard ◽  
Muhammad Haseeb Iqbal ◽  
...  

Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in bilayers on the nanoantenna structure. The spectral data were compared to SEIRAS active gold surfaces based on nanoparticles, plain gold and plain substrate (Si) for different temperatures. The shape of the infrared signals, the peak positions and their relative intensities were found to be sensitive to the type of surface and the presence of an enhancement. The strongest shifts in position and intensity were seen for the nanoantennas, and a smaller effect was seen for the DPPTE immobilized on gold nanoparticles. This information is crucial for interpretation of data obtained for biological molecules measured on such structures, for future application in nanodevices for biologically or medically relevant samples.


1990 ◽  
Author(s):  
Tatsuro Iwabuchi ◽  
Chih-Li Chuang ◽  
Galina Khitrova ◽  
Mial E. Warren ◽  
Arturo Chavez-Pirson ◽  
...  

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