Low Fluorescence Yield Research Articles

Luminescence performance and antioxidant properties of selenium carbon dots prepared from selenium-hyperaccumulating plants.

Heteroatom doping has become an important method to enhance the performance of traditional carbon dots in modern times. Selenium (Se) is a nonmetallic trace element with excellent redox properties and is therefore essential for health. Previous studies have mainly used pure chemicals as selenium sources to prepare selenium-doped carbon dots (Se-CDs), but the precursor pure chemicals have the disadvantages of being expensive, difficult to obtain, toxic, and having low fluorescence yields of the synthesised Se-CDs. Fortunately, our team achieved successful synthesis of selenium carbon dots, exhibiting excellent luminescence and biocompatibility through a one-step hydrothermal method using selenium-enriched natural plant Cardamine, as an alternative to selenium chemicals. This approach aims to address the limitations and high costs associated with Se-CDs precursors. Electron spin resonance spectroscopy (ESR) and cellular antioxidant tests have confirmed the protective ability of Se-CDs against oxidative damage induced by excessive reactive oxygen species (ROS). A new concept and method for synthesizing selenium carbon dots on the basis of biomass, a rationale for the antioxidant effects on human health, and a wide range of development and application possibilities were offered in this work.

Green Synthesis of Various Heteroatom‐doped Carbon Quantum Dots from Urine, Whey, and Their Mixture: The Optimization of Synthesis and Potential Applications

AbstractThe employment of biomass waste for the fabrication of carbon quantum dots (CQDs), as a novel fluorescent material with high photoluminescence (PL) activity, has gained intense interest for the last decade. However, the fabrication of CQD from biomass waste encounters challenges including low fluorescence yield, reproducibility, and stability. Therefore, the novel, simple, flexible fabrication routes for CQDs using biomass waste as a precursor are still essential for practical applications. In this study, we reported the employment of human urine (U), sour whey (W), and their mixture (U/W) as precursors for the hydrothermal green synthesis approach. For all cases, CQDs with an excitation‐dependent emission nature were obtained with a quantum yield (QY) value of 48 %, 28 %, and 39 % for U, W, and U/W, respectively. For each case, doping of various heteroatoms such as N, P, S, etc., in the structure of CQDs contributed PL characteristics with high QY, reasonably low cytotoxicity, and, robust pH and storage stability which indicate their high potential in various biomedical applications such as bioimaging and pH sensors. This study proves the utilization of human urine and whey as the precursors for the fabrication of CQDs through a low‐cost, flexible, and eco‐friendly green synthesis procedure.

Photoisomerization mechanism of iminoguanidinium receptors from spectroscopic methods and quantum chemical calculations.

The hydrazone functional group, when coupled with a pyridyl substituent, offers a unique class of widely tunable photoswitches, whose E-to-Z photoisomerization equilibria can be controlled through intramolecular hydrogen bonding between the N-H hydrazone donor and the pyridyl acceptor. However, little is known about the photoisomerization mechanism in this class of compounds. To address this issue, we report a pyridine-appended iminoguanidinium photoswitch that is functionally related to acylhydrazones and provides insight into the photoisomerization processes between the E and Z configurations. The E-to-Z photoisomerization of the E-2-pyridyl-iminoguanidinium cation (2PyMIG) in DMSO, prepared as the bromide salt, was quantified by 1H NMR, and probed in real time with ultrafast laser spectroscopy. The photoisomerization process occurs on a picosecond timescale, resulting in low fluorescence yields. The multiconfigurational reaction path found with the growing string method features a small barrier (4.3 or 6.5 kcal mol-1) that the E isomer in the π-π* state must overcome to reach the minimum energy conical intersection (MECI) connecting the E and Z isomers of 2PyMIG. While two possible pathways exist depending on the orientation of the pyridine ring, both exhibit the same qualitative features along the path and at their MECIs, involving simultaneous changes in the CCNN and CNNC dihedral angles. Furthermore, the ground state barrier for pyridine ring rotation is readily accessible, thus a low barrier pathway to the experimentally observed Z isomer exists for both MECIs leading to a transition from the E isomer to photoproduct. Combining multiconfigurational reaction path calculations using growing string method with time-resolved fluorescence spectroscopy provided crucial insights into the photoisomerization process of 2PyMIG, resulting in both the computational and experimental results pointing to rapid photoisomerization via a surface crossing between the singlet π-π* and the ground states.

Excited State Dynamics of Dibenzothiophene Derivatives.

Polycyclic aromatic sulfur heterocycles are environmental pollutants formed from incomplete combustion processes and crude oil spills. Their excited state dynamics are not understood. Herein, femtosecond transient absorption is combined with steady-state spectroscopy and computational methods to elucidate the relaxation mechanisms of three dibenzothiophene derivatives. The low-energy singlet and triplet states all have ππ* character in the Franck-Condon region, and two minima were located in the S1 surface. Excitation at 320 nm populates their S1 state directly, which relaxes with lifetimes ranging from 4 to 13 ps. Most of the S1 population undergoes efficient intersystem crossing to the triplet state with lifetimes ranging from 820 ± 50 to 900 ± 30 ps. The compounds exhibit negligible nonradiative internal conversion, low fluorescence yields of 1.2 to 1.6%, and triplet yields of ca. 98%. Linear interpolation of internal coordinates reveals the chemical basis for relaxing the spin-forbidden intersystem crossing in these π-aromatic systems.

Combined experimental and computational studies on the photophysical properties of systematically substituted polypyridyl based ligands on a benzene core

• Investigated dendritic systems show interesting solvent modulated photophysics; • Inter-chromophoric interaction is present in highly substituted systems; • Theoretical calculation results support the experimental observations; • Strongly modulated photochemistry of L1 and L2 in lower DMSO fraction; • Can lead to design new antenna systems with bipyridyl chromophores on benzene core. Photophysical behavior of ligands containing systematically substituted 2,2′-dipyridylamine (DPyA) chromophores on a benzene core was studied by steady-state and time resolved fluorescence experiments in combination with density functional theory (DFT) calculations. All the investigated derivatives show significant solvent modulated photophysical properties. The redshift along with the broadening in fluorescence spectra in polar protic environments could be explained by the formation of extensive solvent hydrogen bonding network with the investigated compounds. On the other hand, extremely low fluorescence yield in aqueous medium is mostly due to the significant drop in radiative deactivation pathway. In addition to the polarity outcome, the contribution of specific interactions like solvent hydrogen bond formation towards the spectral properties were examined by multi-parametric linear regression analysis using Kamlet-Taft (KT) and Catalán formalisms. While the mono and di-substituted systems ( L1 and L2 , respectively) show almost similar excited state deactivation parameters, additional interchromophoric interaction is predicted in the tri-substituted derivative ( L3 ). The experimental results were verified with TDDFT studies on isolated as well as micro-solvated ligand-water complexes.

Precise Detection and Visualization of Cyclooxygenase-2 for Golgi Imaging by a Light-Up Aggregation-Induced Emission-Based Probe

Precise Detection and Visualization of Cyclooxygenase-2 for Golgi Imaging by a Light-Up Aggregation-Induced Emission-Based Probe

Deciphering Spectroscopic and Structural Insights into the Photophysical Behavior of 2,2'-Dipyridylamine: An Efficient Environment Sensitive Fluorescence Probe.

Excited state deactivation properties and the effects of solvent hydrogen bonding (HB) on the photophysical behavior of 2,2'-dypyridylamine (DPyA) were investigated by steady state and time-resolved fluorescence experiments, molecular docking, and density functional theory (DFT) calculations. In addition to the polarity effect, the contributions of solvent HB donation (HBD) acidity and HB acceptance (HBA) basicity to modulate the solvatochromic spectral properties were estimated from multiparametric linear regression analysis using Kamlet-Taft (KT) and Catalán formalisms. The importance of C-N bond torsion, leading to the trans → cis conversion, was manifested by substantial increase in DPyA fluorescence yield in the presence of cyclodextrin (CD) and glycerol. The unusually low fluorescence yield in aqueous medium was explained on the basis of synergistic effect of solvent hydrogen bonding combined with excited state conformational isomerization, which renders DPyA to be an excellent environment sensitive fluorescence reporter. The experimental results were verified with structural insights obtained from DFT calculations at B3LYP/6-311++G(d,p) level and construction of potential energy surface (PES) in the ground state as well as in the excited states.

Scalable hyperfine qubit state detection via electron shelving in the 2D5/2 and 2F7/2 manifolds in 171Yb+

Qubits encoded in hyperfine states of trapped ions are ideal for quantum computation given their long lifetimes and low sensitivity to magnetic fields, yet they suffer from off-resonant scattering during detection, often limiting their measurement fidelity. In ${}^{171}{\text{Yb}}^{+}$ this is exacerbated by a low fluorescence yield, which leads to a need for complex and expensive hardware, a problematic bottleneck especially when scaling up the number of qubits. We demonstrate a detection routine based on electron shelving to address this issue in ${}^{171}{\text{Yb}}^{+}$ and achieve a $5.6\ifmmode\times\else\texttimes\fi{}$ reduction in single-ion detection error on an avalanche photodiode to $1.8(2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ in a 100 $\ensuremath{\mu}\mathrm{s}$ detection period and a $4.3\ifmmode\times\else\texttimes\fi{}$ error reduction on an electron multiplying CCD camera with $7.7(2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ error in 400 $\ensuremath{\mu}\mathrm{s}$. We further improve the characterization of a repump transition at 760 nm to enable a more rapid reset of the auxiliary ${}^{2}{F}_{7/2}$ states populated after shelving. Finally, we examine the detection fidelity limit using the long-lived ${}^{2}{F}_{7/2}$ state, achieving further $300\ifmmode\times\else\texttimes\fi{}$ and $12\ifmmode\times\else\texttimes\fi{}$ reductions in error to $6(7)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and $6.3(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ in 1 ms on the respective detectors. While shelving-rate limited in our setup, we suggest various techniques to realize this detection method at speeds compatible with quantum information processing, providing a pathway to ultrahigh-fidelity detection in ${}^{171}{\text{Yb}}^{+}$.

Hexamethine hemicyanine dye as a thermo-optical probe for serum albumin

In the present work, we demonstrate the usefulness of a hexamethine hemicyanine dye as a thermo-optical probe for serum albumin, an abundant transport protein in the circulatory system, and its optimum concentration is often considered as an indicator of good health. For this purpose, the interaction of near-infrared (NIR) hemicyanine dye, LDS 821 (Styryl 9 M) with bovine serum albumin (BSA) and human serum albumin (HSA) has been investigated using various spectroscopic techniques and molecular docking method. The gradual red-shift in UV–vis absorption and an increase in the emission intensity of the hemicyanine dye upon incremental addition of serum albumin indicating the binding of the dye with the protein. The circular dichroism spectroscopy studies revealed an increase in the α-helix content of protein with an increase in dye concentration specifying enhanced stability of proteins upon binding with the dye. The results of these studies imply that binding of hemicyanine dye to the hydrophobic pockets of serum albumin considerably alters its optical properties by reducing the mobility and structural flexibility of the dye. Based on this understanding, thermo-optical properties of the dye in the absence and presence of serum albumin have been analyzed using a dual-beam mode matched thermal lens technique, which measures a rise in temperature due to the nonradiative relaxation of the excited state energy of the dye. A considerable decrease in the thermal diffusivity of the dye (1.39 × 10−3 cm2/sec) in the presence of 0.1–0.7 μm HSA (1.30–0.99 × 10−3 cm2/sec) and BSA (1.33–0.97 × 10−3 cm2/sec) has been observed owing to the change in the heat diffusion capacity of the dye bounded with protein. The low fluorescence yield and the ability to bind in the interior of protein molecules make NIR emissive hemicyanine dye LDS 821 a potential thermo-optical probe for detecting serum albumin, an aspect unexplored for this class of dyes. The present study demonstrates that the thermal lens method with a suitable thermo-optical probe can be used as a sensing method for serum albumin.

Determination of the Li Distribution in Synthetic Recycling Slag with SIMS

The recovery of technically important elements like lithium from slag of pyrometallurgical recycling of lithium traction batteries will be very important in future due to the expected increasing demand of this element with the upcoming world-wide implementation of electro mobility. Therefore, the investigation of possibilities to recover lithium from pyrometallurgical slag from the recycling of lithium traction batteries is mandatory. In this context, the EnAM (engineered artificial mineral) approach is very promising. Solidified melt of synthetic recycling slag with the compounds Li2O-MgO-Al2O3-SiO2-CaO-MnO contains various Li-bearing phases including spinel solid solution, Li-aluminate and eucryptite-like Li-alumosilicate. Most probably, the Ca-alumosilicate matrix (melilite-like solid solution) incorporates lithium as well. These compounds can be determined and calculated to an acceptable approximation with electron probe microanalysis (EPMA). Nevertheless, an adequate precise measurement of lithium is virtually impossible due to the extremely low fluorescence yield and long wavelength of Li Kα. Secondary mass spectrometry (SIMS) can be used to fill this gap in the analytical assessment of the slag. Therefore, the combination of these two analytical methods can distinctively improve the mineralogical and chemical characterization of lithium-containing solidified (slag) melt.

3-(4-Carboxybenzoyl)quinoline-2-carboxaldehyde labeling for direct analysis of amino acids in plasma is not suitable for simultaneous quantification of tryptophan, tyrosine, valine, and isoleucine by CE/fluorescence.

Capillary electrophoresis coupled to LED-induced fluorescence detection is a robust and sensitive technique used for amino acids (AA) analysis in biological media, after labeling with 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA). We wanted to quantitate in plasma tryptophan (Trp), tyrosine (Tyr), valine (Val), and isoleucine (Ile). Among the different labeled AA-CBQCA, Trp has the lowest fluorescence yield, which makes its detection and quantification very difficult in biological samples such as plasma. We tried to improve Trp analysis by CE/LED-induced fluorescence detection to its maximal sensitivity by using large volume sample stacking as a preconcentration step in our analytical protocol. At pH 9.5, this step caused a drop in resolution during the separation of the four AAs and it was therefore necessary to work at pH 10. We have found that Tyr, Val, Ile, and Trp are detected and well separated from the other AAs, but Trp cannot be quantified in plasma samples, mainly because of the low fluorescence yield of the Trp-CBQCA derivative. The recorded LOD is 0.18μM for Trp-CBQCA in standard solution with a resolution between Trp and Tyr of 1.2, while the LOD is 6μM in plasma with the same resolution. Trp, Tyr, Val, and Ile are, however, efficiently quantified when using a 3 M acetic acid electrolyte and CE associated with capacitively coupled contactless conductivity detection, which also has the advantage of not requiring derivatization or large volume sample stacking. This article demonstrates, for the CE user, that quantitative analysis of these four AA in mouse plasma can be performed by CE-fluorescence after CBQCA labeling, with the exception of Trp. It can be advantageously replaced by CE/capacitively coupled contactless conductivity detection, the only efficient one for Trp, Tyr, Val, and Ile quantification. In this case, the LOD for Trp is 2μM. The four AAs are separated with resolution with neighbors above 1.5.

Single-Walled Carbon Nanotube Sensor Platform for the Study of Extracellular Analytes.

Single-walled carbon nanotubes (SWNT) are attractive targets for the formation of high-density sensor arrays. Their small size and high reactivity could allow for the spatial and temporal study of extracellular products to a degree which greatly surpasses contemporary sensors. However, current methods of SWNT immobilization produce a low fluorescence yield that requires a combination of high magnification, exposure time, and laser intensity to combat, thus limiting the sensor's applications. In this work, a platform for the immobilization of SWNT sensors with increased fluorescence yield, longevity, fluorescence distribution, and fast reaction times is developed.

6‐phenylpyrrolocytosine as a fluorescent probe to examine nucleotide flipping catalyzed by a DNA repair protein

Cellular exposure to tobacco-specific nitrosamines causes formation of promutagenic O6 -[4-oxo-4-(3-pyridyl)but-1-yl]guanine (O6 -POB-G) and O6 -methylguanine (O6 -Me-G) adducts in DNA. These adducts can be directly repaired by O6 -alkylguanine-DNA alkyltransferase (AGT). Repair begins by flipping the damaged base out of the DNA helix. AGT binding and base-flipping have been previously studied using pyrrolocytosine as a fluorescent probe paired to the O6 -alkylguanine lesion, but low fluorescence yield limited the resolution of steps in the repair process. Here, we utilize the highly fluorescent 6-phenylpyrrolo-2'-deoxycytidine (6-phenylpyrrolo-C) to investigate AGT-DNA interactions. Synthetic oligodeoxynucleotide duplexes containing O6 -POB-G and O6 -Me-G adducts were placed within the CpG sites of codons 158, 245, and 248 of the p53 tumor suppressor gene and base-paired to 6-phenylpyrrolo-C in the opposite strand. Neighboring cytosine was either unmethylated or methylated. Stopped-flow fluorescence measurements were performed by mixing the DNA duplexes with C145A or R128G AGT variants. We observe a rapid, two-step, nearly irreversible binding of AGT to DNA followed by two slower steps, one of which is base-flipping. Placing 5-methylcytosine immediately 5' to the alkylated guanosine causes a reduction in rate constant of nucleotide flipping. O6 -POB-G at codon 158 decreased the base flipping rate constant by 3.5-fold compared with O6 -Me-G at the same position. A similar effect was not observed at other codons.

An improved and highly selective fluorescence assay for measuring phosphatidylserine decarboxylase activity

Phosphatidylserine decarboxylases (PSDs) catalyze the conversion of phosphatidylserine (PS) to phosphatidylethanolamine (PE), a critical step in membrane biogenesis and a potential target for development of antimicrobial and anti-cancer drugs. PSD activity has typically been quantified using radioactive substrates and products. Recently, we described a fluorescence-based assay that measures the PSD reaction using distyrylbenzene-bis-aldehyde (DSB-3), whose reaction with PE produces a fluorescence signal. However, DSB-3 is not widely available and also reacts with PSD's substrate, PS, producing an adduct with lower fluorescence yield than that of PE. Here, we report a new fluorescence-based assay that is specific for PSD and in which the presence of PS causes only negligible background. This new assay uses 1,2-diacetyl benzene/β-mercaptoethanol, which forms a fluorescent iso-indole-mercaptide conjugate with PE. PE detection with this method is very sensitive and comparable with detection by radiochemical methods. Model reactions examining adduct formation with ethanolamine produced stable products of exact masses (m/z) of 342.119 and 264.105. The assay is robust, with a signal/background ratio of 24, and can readily detect formation of 100 pmol of PE produced from Escherichia coli membranes, Candida albicans mitochondria, or HeLa cell mitochondria. PSD activity can easily be quantified by sequential reagent additions in 96- or 384-well plates, making it readily adaptable to high-throughput screening for PSD inhibitors. This new assay now enables straightforward large-scale screening for PSD inhibitors against pathogenic fungi, antibiotic-resistant bacteria, and neoplastic mammalian cells.

Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans

Genetically encoded voltage indicators (GEVIs) based on microbial rhodopsins utilize the voltage-sensitive fluorescence of all-trans retinal (ATR), while in electrochromic FRET (eFRET) sensors, donor fluorescence drops when the rhodopsin acts as depolarization-sensitive acceptor. In recent years, such tools have become widely used in mammalian cells but are less commonly used in invertebrate systems, mostly due to low fluorescence yields. We systematically assessed Arch(D95N), Archon, QuasAr, and the eFRET sensors MacQ-mCitrine and QuasAr-mOrange, in the nematode Caenorhabditis elegans ATR-bearing rhodopsins reported on voltage changes in body wall muscles (BWMs), in the pharynx, the feeding organ [where Arch(D95N) showed approximately 128% ΔF/F increase per 100 mV], and in neurons, integrating circuit activity. ATR fluorescence is very dim, yet, using the retinal analog dimethylaminoretinal, it was boosted 250-fold. eFRET sensors provided sensitivities of 45 to 78% ΔF/F per 100 mV, induced by BWM action potentials, and in pharyngeal muscle, measured in simultaneous optical and sharp electrode recordings, MacQ-mCitrine showed approximately 20% ΔF/F per 100 mV. All sensors reported differences in muscle depolarization induced by a voltage-gated Ca2+-channel mutant. Optogenetically evoked de- or hyperpolarization of motor neurons increased or eliminated action potential activity and caused a rise or drop in BWM sensor fluorescence. Finally, we analyzed voltage dynamics across the entire pharynx, showing uniform depolarization but compartmentalized repolarization of anterior and posterior parts. Our work establishes all-optical, noninvasive electrophysiology in live, intact C. elegans.

Ratiometric detection of tetracycline based on gold nanocluster enhanced Eu3+ fluorescence

Tetracycline (TC), a widely-used antibiotic to treat bacterial infections, combines with Eu3+ to form a stable EuTC complex that has a low fluorescence (FL) yield because of Eu3+ coordination with water molecules. We report a simple, label-free ratiometric fluorescent platform for sensitively and selectively sensing of TC, using L-histidine caped gold nanoclusters (His-AuNCs) as a FL indicator and an enhancer of Eu3+ FL. The His-AuNCs were prepared via chemical reduction of Au(III) by L-histidine, which was a reducer and a protecting agent. The His-AuNCs exhibited good photostability, outstanding stability toward high ionic strengths, storage stability, and favorable optical properties. In the absence of TC, the AuNCs-Eu3+ system displays strong FL emission at 475 nm (F475) from the His-AuNCs and weak FL at 620 nm from Eu3+ (F620) with excitation at 375 nm. TC quenches the His-AuNC FL and greatly enhances the Eu3+ emission. This is attributed to an enhancement of the EuTC complex fluorescence by the His-AuNCs. Thus, a ratiometric F620/F475 FL signal can be used for TC detection by simply mixing AuNCs and Eu3+. Under the optimized conditions, the linear range from 10 nM to 60 μM and a detection limit of 4 nM (S/N = 3) for TC were obtained. The application of the assay platform for the detection of TC in environmental and biological samples was demonstrated. The sensing platform has advantages of easy preparation, rapid response, high sensitivity, and good selectivity.

“Bottom-up” preparation of MoS2 quantum dots for tumor imaging and their in vivo behavior study

“Bottom-up” method is a popular approach for the preparation of molybdenum disulfide quantum dots (MoS2 QDs) benefitting from less time consumption and no high-powered sonication required. But the relatively low fluorescent quantum yield of the obtained MoS2 QDs and the rare study about their in vivo behavior stimulate us to do more research in this area. In this paper, we proposed a “bottom-up” hydrothermal method to prepare MoS2 QDs with a quantum yield (QY) of 34.55% by optimizing a series of reaction conditions. The successful fluorescence imaging of tumor cells in vitro and in vivo as well as the systematic in vivo behavior study such as biocompatibility, biodistribution and metabolism route provided the good basis for their wider biomedical applications.

Scanning transmission X-ray microscopy with efficient X-ray fluorescence detection (STXM-XRF) for biomedical applications in the soft and tender energy range.

Scanning transmission X-ray microscopy, especially in combination with X-ray fluorescence detection (STXM-XRF) in the soft X-ray energy range, is becoming an increasingly important tool for life sciences. Using X-ray fluorescence detection, the study of biochemical mechanisms becomes accessible. As biological matrices generally have a low fluorescence yield and thus a low fluorescence signal, high detector efficiency (e.g. large solid angle) is indispensable for avoiding long measurement times and radiation damage. Here, the new AnImaX STXM-XRF microscope equipped with a large solid angle of detection enabling fast scans and the first proof-of-principle measurements on biomedical samples are described. In addition, characterization measurements for future quantitative elemental imaging are presented.

Light harvesting control in plants.

In 1991, my colleagues and I published a hypothesis article that proposed a mechanism that controls light harvesting in plants and protects them against photodamage. The major light harvesting complex, LHCII, was suggested to undergo aggregation upon exposure of the plant to damaging levels of light. Aggregated LHCII was found to be much less efficient in light harvesting, as it promptly dissipated absorbed energy into heat, possessing a very low chlorophyll fluorescence yield. Nonphotochemical quenching (NPQ) is a term coined to describe this reduction in chlorophyll fluorescence yield. This article is a story of how the hypothesis that LHCII aggregation is involved in NPQ is developed into a model that is now becoming broadly accepted by the research community.

Photophysical and electrochemical properties of oligothiophene in non-polymeric and polymeric solvents

Effect of different solvents on emission behaviour of oligothiophene (OT) has been explored in this article. OT was synthesized using a modified cationic surfactant assisted polymerization technique. The average molecular weight was 1006 (which indicated an addition of 12 thiophene units) with a wider distribution (solid state crystallinity of 26% from X-ray crystallography). A gradient solubility of OT was obtained in N, N-dimethyl sulphoxide (95%), ethanol (82%) and chloroform (65%) due to descending solvochromatic interaction. A higher emission intensity (blue) and fluorescent quantum yield (11%) was obtained in DMSO than in ethanol (quantum yield 7%) due to a lower HOMO-LUMO transition energy. Conversely, excitation in a high molecular weight solvent like poly (vinyl alcohol) displayed a low emission intensity and fluorescent quantum yield (3%) despite lower HOMO-LUMO transition energy mainly due to quenching effect. Instead, such a system was suited for a capacitative action as demonstrated through cyclic voltametric measurement.