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Plasmonic Nanochips Development and Applications
Published in Volodymyr I. Chegel, Andrii M. Lopatynskyi, Molecular Plasmonics, 2020
Volodymyr I. Chegel, Andrii M. Lopatynskyi
For determined sizes of the gold and silver nanostructures, the profiles of electric field intensity enhancement around the nanoparticles were calculated (Figs. 3.35a, c). These enhancement values correlate with the increase in the fluorescence excitation rate [209]. The calculation was performed at 532 nm, which is an inherent excitation wavelength for the organic dye Rhodamine 6G (R6G). The maximum electric field intensity enhancement value calculated on the 30 × 30 nm2 area outside the nanostructure in the plane in which the propagation vector and polarization vector of incident light wave lie was about 100 times for silver nanostructure and about 30 times for gold nanostructure. The broadening in the extinction spectra of silver NSA, observed in the experiment, compared with the simulation results (Fig. 3.35b), can be explained by the growing mismatch between the model semi-ellipsoid and experimental nanostructure shapes and variety of sizes of nanostructures in the NSA. Thus, silver nanostructures produced by thermal annealing of island films are potentially more promising in creating the nanochip. However, the gold nanostructures are mostly used in most scientific researches at the present time due to their higher chemical stability.
Optical Absorption and Fluorescence of Nanomaterials
Published in Vladimir I. Gavrilenko, Optics of Nanomaterials, 2019
The Rhodamine 6G (Rh6G) is a highly fluorescent rhodamine family dye. Rh6G as well as other Rhodamine family dyes are used extensively in biotechnology applications such as fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy. The Rh6G is also used as a laser dye, or gain medium, in dye lasers. It has a remarkably high photostability, high luminescence quantum yield (near 0.95), low cost, and its lasing range has close proximity to its absorption maximum. The electron energy structure of the Rh6G molecule has electron levels responsible for the singlet type optical transitions well separated on the energy scale from the backbone electronic structure. This electron energy structure of the Rh6G molecule results in a typical optical absorption and strong luminescence lines that are well separated from the optical spectra related to the excitation of the backbone electronic orbitals (Gavrilenko and Noginov, 2006).
Lasers for Spectroscopy
Published in Leon J. Radziemski, Richard W. Solarz, Jeffrey A. Paisner, Laser Spectroscopy and Its Applications, 2017
There are other excited electronic states in dye molecules which can influence laser properties. There are allowed electronic absorptions from the ground state to higher-lying electronic states as well as to the lowest singlet state S1. The absorption from 250 to 400 nm in the DCM spectrum of Fig. 2.3, for example, takes the molecule to these higher-lying states. In all but a few cases (which do not include laser dyes) these excited singlet states are quenched to the first excited singlet state much faster than they can radiate so absorption at wavelengths shorter than the S1 absorption band can also be used to pump the laser. These absorptions are broad and intense in DCM dye, which makes it a good candidate for pumping by short-wavelength sources or broadband radiators such as xenon flash lamps [Hammond, 1978; Weber, 1983]. As Fig. 2.2 shows, rhodamine 6G has very little absorption from about 360 to 450 nm, so sources in this wavelength range do not pump this dye well. There is significant absorption from 360 nm to shorter wavelength (see Drexhage, 1973, Fig. 4.4) and rhodamine 6G can be used with pump wavelengths in that region.
Laser induced fluorescence detection of R6G dye adsorbed on Fe3O4 nanomaterials
Published in Journal of Applied Water Engineering and Research, 2022
Yasmin El-Dakrory, Mahmoud Sliem, Maha Abdelkreem, Salah Hassab Elnaby, Reham Rezk
Industrial revolution and overpopulation caused dense pollution especially in wastewater contaminated with large amounts of dyes and heavy metals (Hoan et al., 2017; Saranya et al., 2020). Water pollution with synthetic dyes comes from the industries of plastics, textile, paper, wool, and cotton (Alizadeh et al., 2016; Gautam et al., 2020; Patra et al., 2020). Rhodamine 6G (R6G) is one of the rhodamine family which is known as a basic dye. It is mainly used to dye silk, wool, foodstuff, cotton, and paper. Drinking water contaminated with Rhodamine dyes could lead to subcutaneous tissue-borne sarcoma that is highly carcinogenic (Pal et al., 2016). Up till now, several methods have been used to treat wastewater from dyes such as photocatalytic degradation, oxidation, filtration, coagulation, flocculation, biodegradation, and adsorption (Zhang et al., 2011). One of the most effective methods is the adsorption technique because of its versatility, wide applicability, and economic feasibility (Chowdhury and Balasubramanian, 2014; Mekkey, 2017).
Fluorescent determination of trinitrotoluene with bovine serum albumin mediated enhancement of thioglycolic acid capped cadmium selenium quantum dots
Published in Instrumentation Science & Technology, 2018
The fluorescence quantum yield of thioglycolic acid capped CdSe quantum dots was calculated by a comparative method[25]: where m is the slope of the plot of the integrated fluorescence intensity versus absorbance, n is the refractive index of solvent, and R is the reference dye. A standard solution of rhodamine-6G with an excitation wavelength from 248 to 528 nm and emission wavelength of 510 to 700 nm was prepared in ethanol at a concentration of 1.05 × 10−7 mol L−1. The quantum yield of rhodamine-6G (QR) is 0.95. The corresponding refractive indices of water (n) and ethanol solution (nR) at 20 °C are 1.34 and 1.36, respectively. Both the sample and the reference were excited at 400 nm.
A rhodamine hydrazide–4-nitroindole-3-carboxaldehyde based turn on Hg2+ chemosensor: cytoplasmic live cell imaging, logic gate and memory device applications and computational studies
Published in Journal of Coordination Chemistry, 2018
Rahul Bhowmick, Abu Saleh Musha Islam, Mihir Sasmal, Atul Katarkar, Mahammad Ali
First rhodamine 6G hydrochloride (3 g, 6.25 mmol) and hydrazine hydrate (6 mL, 16 mmol) were taken in a round bottom flask in 50 mL ethanol and refluxed for 3 h with continuous stirring. Then the reaction mixture was cooled and poured in 200 mL cold distilled water and kept in a refrigerator overnight. An off white product was isolated by filtration and washed thoroughly with water.