UV Response Research Articles

Reconsidering the role of receptors for SARS‐CoV‐2 in clear cell renal cell carcinoma: Friends or foes

Reconsidering the role of receptors for SARS‐CoV‐2 in clear cell renal cell carcinoma: Friends or foes

Enhancing the UV Response of All-Inorganic Perovskite Photodetectors by Introducing the Mist-CVD-Grown Gallium Oxide Layer

All-inorganic perovskites, with their low-cost, simple processes and superior heat stability, have become potential candidate materials for photodetectors (PDs). However, they have no representative responsivity in the deep-ultraviolet (UV) wavelength region. As a new-generation semiconductor, gallium oxide (Ga2O3), which has an ultrawide bandgap, is appropriate for solar-blind (200 nm–280 nm) deep-UV detection. In this work, ultrawide-bandgap Ga2O3 was introduced into an inorganic perovskite device with a structure of sapphire/β-Ga2O3/Indium Zinc Oxide (IZO)/CsPbBr3. The performance of this perovskite PD was obviously enhanced in the deep UV region. A low-cost, vacuum-free Mist-CVD was used to realize the epitaxial growth of β-Ga2O3 film on sapphire. By introducing the Ga2O3 layer, the light current of this heterojunction PD was obviously enhanced from 10−8 to 10−7, which leds its detectivity (D*) to reach 1.04 × 1012 Jones under a 254 nm light illumination with an intensity of 500 μW/cm2 at a 5 V bias.

Binder polymer influence on the electrical and UV response of organic field-effect transistors

Organic field-effect transistors (OFETs) and phototransistors using blends of Ph-BTBT-10 with binding polymers are prepared. We show that tuning the nature of the polymer is a useful tool to optimise the OFET performance and photoresponsivity.

Dual-mode luminescence anti-counterfeiting and white light emission of NaGdF4:Ce,Eu,Tb/carbon dot hydrophilic nanocomposite ink.

NaGdF4:Ce,Eu,Tb nanocrystals were successfully prepared by a one-step hydrothermal method with Ce3+ ions as sensitizers, Eu3+ and Tb3+ ions as activators, and polyethylenimine (PEI) as surfactants. Color-adjustable fluorescence emission was achieved by the energy transfer effect between rare earth ions. Blue fluorescent carbon quantum dots (CDs) with a double UV response under 254 nm and 365 nm excitation were synthesized by a one-step hydrothermal method. A hydrophilic NaGdF4:Ce,Eu,Tb/CD composite ink was prepared by an easy physical mixing method. Because of the electrostatic self-assembly effect, the color adjustable luminescence was achieved in a few seconds, and the white light emission with color coordinates of (0.32, 0.32) was obtained. A dual-mode luminescence anti-counterfeiting pattern was designed and achieved by excitation with ultraviolet light at 254 nm and 365 nm.

A novel ZnO/viologen photochromic composite film with a rapid UV response for rewritable paper, solar UV detection, smart windows and anti-counterfeiting

The synergistic effects of the photocatalytic activity of ZnO NPs and the photochromic properties of viologens make the film rapidly respond to UV-irradiation.

Transition from Dion-Jacobson hybrid layered double perovskites to 1D perovskites for ultraviolet to visible photodetection.

New perovskite phases having diverse optoelectronic properties are the need of the hour. We present five variations of R2AgM(iii)X8, where R = NH3C4H8NH3 (4N4) or NH3C6H12NH3 (6N6); M(iii) = Bi3+ or Sb3+; and X = Br- or I-, by tuning the composition of (4N4)2AgBiBr8, a structurally rich hybrid layered double perovskite (HLDP). (4N4)2AgBiBr8, (4N4)2AgSbBr8, and (6N6)2AgBiBr8 crystallize as Dion-Jacobson (DJ) HLDPs, whereas 1D (6N6)SbBr5, (4N4)-BiI and (4N4)-SbI have trans-connected chains by corner-shared octahedra. Ag+ stays out of the 1D lattice either when SbBr63- distortion is high or if Ag+ needs to octahedrally coordinate with I-. Band structure calculations show a direct bandgap for all the bromide phases except (6N6)2AgBiBr8. (4N4)2AgBiBr8 with lower octahedral tilt shows a maximum UV responsivity of 18.8 ± 0.2 A W-1 and external quantum efficiency (EQE) of 6360 ± 58%, at 2.5 V. When self-powered (0 V), (4N4)-SbI has the best responsivity of 11.7 ± 0.2 mA W-1 under 485 nm visible light, with fast photoresponse ≤100 ms.

UV Radiation Induces Specific Changes in the Carotenoid Profile of Arabidopsis thaliana.

UV-B and UV-A radiation are natural components of solar radiation that can cause plant stress, as well as induce a range of acclimatory responses mediated by photoreceptors. UV-mediated accumulation of flavonoids and glucosinolates is well documented, but much less is known about UV effects on carotenoid content. Carotenoids are involved in a range of plant physiological processes, including photoprotection of the photosynthetic machinery. UV-induced changes in carotenoid profile were quantified in plants (Arabidopsis thaliana) exposed for up to ten days to supplemental UV radiation under growth chamber conditions. UV induces specific changes in carotenoid profile, including increases in antheraxanthin, neoxanthin, violaxanthin and lutein contents in leaves. The extent of induction was dependent on exposure duration. No individual UV-B (UVR8) or UV-A (Cryptochrome or Phototropin) photoreceptor was found to mediate this induction. Remarkably, UV-induced accumulation of violaxanthin could not be linked to protection of the photosynthetic machinery from UV damage, questioning the functional relevance of this UV response. Here, it is argued that plants exploit UV radiation as a proxy for other stressors. Thus, it is speculated that the function of UV-induced alterations in carotenoid profile is not UV protection, but rather protection against other environmental stressors such as high intensity visible light that will normally accompany UV radiation.

Flares in the changing look AGN Mrk 590 – I. The UV response to X-ray outbursts suggests a more complex reprocessing geometry than a standard disc

ABSTRACT Mrk 590 is a known changing-look active galactic nuclei (AGNs) which almost turned off in 2012, and then in 2017 partially re-ignited into a repeat flaring state, unusual for an AGN. Our Swift observations since 2013 allow us to characterize the accretion-generated emission and its reprocessing in the central engine of a changing-look AGN. The X-ray and UV variability amplitudes are higher than those typically observed in ‘steady-state’ AGN at similar moderate accretion rates; instead, the variability is similar to that of highly accreting AGN. The unusually strong X-ray to UV correlation suggests that the UV-emitting region is directly illuminated by X-ray outbursts. We find evidence that the X-rays are reprocessed by two UV components, with the dominant one at ∼3 d and a faint additional reprocessor at near-zero lag. However, we exclude a significant contribution from diffuse broad line region continuum, known to contribute for bonafide AGN. A near-zero lag is expected for a standard ‘lamp-post’ disc reprocessing model with a driving continuum source near the black hole. That the overall UV response is dominated by the ∼3-d lagged component suggests a complicated reprocessing geometry, with most of the UV continuum not produced in a compact disc, as also found in recent studies of NGC 5548 and NGC 4151. None the less, the observed flares display characteristic time-scales of ∼100 rest-frame days, consistent with the expected thermal time-scale in an accretion disc.

Comprehensive Genomic Analysis for Identifying FZD6 as a Novel Diagnostic Biomarker for Acute Myeloid Leukemia.

As a family of G protein-coupled receptors (GPCRs) with a seven-span transmembrane structure, frizzled class receptors (FZDs) play crucial roles in regulating multiple biological functions. However, their transcriptional expression profile and prognostic significance in acute myeloid leukemia (AML) are unclear. In AML, the role of FZDs was explored by performing the comprehensive analysis on the relationship between clinical characteristics and mRNA expression profiles from public databases including cBioPortal for Cancer Genomics, Gene Expression Profile Interactive Analysis (GEPIA), and Cancer Cell Line Encyclopedia (CCLE). We identified that in the majority of 27 AML cell lines, frizzled class receptor 6 (FZD6) was high-expressed. A significantly higher expression of FZD6 in AML patients was observed when compared to normal controls (P < 0.01). Compared with intermediate and poor/adverse risk group patients, FZD6 expressed much lower in cytogenetic favorable risk group patients (P < 0.0001). Patients with higher-expressed FZD6 were associated with shorter overall survival (OS) (P = 0.0089) rather than progression-free survival (PFS). However, the predictive effect of FZD6 on OS could be reversed by hematopoietic stem cell transplantation (HSCT). The data of gene set enrichment analysis (GSEA) demonstrated that 4 gene sets, including MYC targets, HEME metabolism, E2F targets, and UV response, were differentially enriched in the high-expression FZD6 group. To conclude, the study suggested that high expression of FZD6 might be a novel poor prognostic biomarker for AML treatment.

Dual-band and binary response of high-performance photodetectors with bithiophene-difluoroquinoxaline based copolymers via side chain engineering towards secure optical communication

In present work, three bithiophene-difluoroquinoxaline (TQ) random copolymers (PTQ1-PTQ3) with the similar conjugated skeleton and different substituted side chains such as alkyl, phenyl, and ester groups are designed and synthesized using the direct C–H/C–H coupling polymerization method. All polymers exhibit intense UV absorbance and shallow highest occupied molecular orbital (HOMO) levels, and their photophysical properties could be effectively manipulated by engineering the TQ side chains. The PTQ3, which contains two phenyl groups on 2- and 3-position of 6,7-difluoroquinoxaline units and two dioctyl groups on 4- and 4′- position of 2,2′-bithiophene units, displays intramolecular charge transfer (ICT) character, optimized energy levels, and high hole mobility of 6.4 × 10−4 cm2 V−1 s−1. Furthermore, these polymers blending with small molecular acceptor 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetralcis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d']-s-indanone[1,2-b:5,6-b']-dithiophene (ITIC) are evaluated as photosensitive layers in polymer photodetectors (PPDs) for light detection. All devices show the dual-band photoresponse and self-powered effect. Especially, PTQ3-based device exhibits an extremely low dark current density of 8.1 × 10−10 A cm−2, a superior external quantum efficiency (EQE) of 33.9% and a high photo-detectivity exceeding 6.0 × 1012 Jones under 365 nm at 0 V, outperforming the reported thiophene-quinoxaline based PPDs. Moreover, an interesting binary response of optimal PPD has been demonstrated by imposing small external bias voltages, which is conducive to the transmission of multi-encoding information. Then, we also propose a feasible encryption scheme for optical communication by modulating the UV and red dual-band response of the PPD. The results illustrate a viable design strategy for side chain engineered bithiophene-difluoroquinoxaline based polymers and provide some design guidelines for high-performance PPDs applied in secure optical communication.

High responsivity self-powered flexible broadband photodetector based on hybrid Selenium-PEDOT:PSS junction

Hybrid organic-inorganic composites offer solution processability and ease to construct opto-electronic devices with diverse functionalities, which are desirable for applications like flexible and printed electronics. Trigonal Selenium (t-Se) has been recently investigated for photodetector application, owing to its inherent superior optical properties such as high absorption coefficient and photoconductivity. However, most of the reported Selenium photodetectors use vapor transport based device fabrication techniques which require controlled environments and face scalability issues. In this work, high-performance photodetector based on Selenium-PEDOT:PSS hybrid junction is demonstrated using a facile sonication assisted mechanical mixing and drop-casting technique. XRD and Raman analysis reveals the existence of Selenium in trigonal crystal structure and FE-SEM images show clustered nanoparticles. Selenium is mixed with PEDOT:PSS to form bulk heterojunction, which enhances the electron-hole pair separation efficiency and results in improved device responsivity. Also, due to the favorable band offset between Selenium and PEDOT:PSS which results in built-in field, the photodetector operates in self-biased mode. The device exhibits broad spectral response in UV–Vis–NIR range with responsivities of 0.56 A/W, 66 mA/W and 1.363 A/W at 315 nm, 620 nm and 820 nm, respectively. Response times of 7.7 s, 9.4 s and 6.4 s and external quantum efficiencies (EQE) of 192.58%, 13.25% and 206.55% are obtained for UV, Vis and NIR spectra respectively. Further to validate the robustness, the device is subjected to multiple bending cycles (∼2500) and minimal degradation in performance is observed. Given the simple device architecture and facile device fabrication scheme, this work would enable promising approach for high performance flexible photodetectors. • Selenium, possesses high absorption co-efficient and high photoconductivity with optical bandgap of 1.2–1.5 eV. • However, t-Se has been less explored for photodetector applications. • This work reports a solution-processed hybrid-heterojunction based on Se-PEDOT:PSS for photodetection. • The detector exhibits spectral response from UV–Vis to NIR and significant performance at zero bias condition.

Structural, morphological and photocatalytic properties of Ni-Mn ferrites: Influence of the Ni:Mn ratio

Mixed Ni-Mn ferrite spinel nanoparticles embedded in SiO 2 matrix were prepared by sol-gel method, followed by annealing at 300 and 1000 °C. The thermal analysis and Fourier transform infrared spectroscopy confirmed the formation of Ni-, Mn- and Co- malonate precursors and their decomposition to ferrites. The X-ray diffraction data showed the presence of poorly crystallized Ni-Mn ferrite at 300 °C and of Ni-Mn ferrite accompanied by α-Fe 2 O 3 , cristobalite, quartz and Fe 2 SiO 4 . at 1000 °C. The transmission electron microscopy revealed spherical shape ferrite particles of 19–46 nm diameter, that increase with the increase of Ni content and annealing temperature. For the samples with low Ni content, the pores are larger, their size reaching 100 Å, while for the samples with high Ni content the pores are smaller, their size being lower than 50 Å. The specific surface area increases with the increase of Ni content up to 0.7/0.3 Ni/Mn ratio and after remains constant. The isotherms were used to calculate the rate constants for the decomposition of malonate precursors to ferrites and the activation energy for each ferrite. The samples show a broad response in both UV and visible range, with the maximum in visible domain. Ni 0.5 Mn 0.5 Fe 2 O 4 sample shows the best sonophotocatalytic activity against Rhodamine B solution under visible light irradiation. The prepared Ni-Mn ferrites may have potential application for water and wastewater decontamination. • Ni 0.5 Mn 0.5 Fe 2 O 4 shows the best sonophotocatalytic activity against RhB solution. • In samples with low Ni content, the pore size reaches 100 Å. • In samples with high Ni content, the pore size is lower than 50 Å. • The specific surface area of the samples increases with the increase of Ni content.

Identification and characterization of four immune-related signatures in keloid.

A keloid is a fibroproliferative disorder of unknown etiopathogenesis that requires ill-defined treatment. Existing evidence indicates that the immune system plays an important role in the occurrence and development of keloid. However, there is still a lack of research on the immune-related signatures of keloid. Here we identified immune-related signatures in keloid and explored their pathological mechanisms. Transcriptomic datasets (GSE7890, GSE92566, and GSE44270) of keloid and normal skin tissues were obtained from the Gene Expression Omnibus database. The overlap of differentially expressed genes and immune-related genes was considered as differentially expressed immune-related genes (DEIGs). Functional analysis, expression, and distribution were applied to explore the function and characteristics of DEIGs, and the expression of these DEIGs in keloid and normal skin tissues was verified by immunohistochemistry. Finally, we conducted interactive network analysis and immune infiltration analysis to determine the therapeutic potential and immune correlation. We identified four DEIGs (LGR5, PTN, JAG1, and DKK1). In these datasets, only GSE7890 met the screening criteria. In the GSE7890 dataset, DKK1 and PTN were downregulated in keloid, whereas JAG1 and LGR5 were upregulated in keloid. In addition, we obtained the same conclusion through immunohistochemistry. Functional analysis indicated that these four DEIGs were mainly involved in stem cell, cell cycle, UV response, and therapy resistance. Through interactive network analysis, we found that these DEIGs were associated with drugs currently used to treat keloid, such as hydrocortisone, androstanolone, irinotecan, oxaliplatin, BHQ-880, and lecoleucovorin. Finally, many immune cells, including CD8+ T cells, resting memory CD4+ T cells, and M1 macrophages, were obtained by immune infiltration analysis. In conclusion, we identified four immune signaling molecules associated with keloid (LGR5, PTN, JAG1, and DKK1). These immune-related signaling molecules may be important modules in the pathogenesis of keloid. Additionally, we developed novel therapeutic targets for the treatment of this challenging disease.

Multiresponsive chemosensors based on ferrocenylimidazo[4,5-b]pyridines: Solvent-dependent selective dual sensing of Hg2+ and Pb2+

Two new chemosensors, namely, 2-ferrocenyl-5-(pyridin-3-yl)-1H-imidazo[4,5-b]pyridine (L1) and 2-ferrocenyl-6-(pyridin-3-yl)-1H-imidazo[4,5-b]pyridine (L2), were synthesized and characterized. Furthermore, the solid-state structure of L1 was unequivocally established by X-ray diffraction analysis. These nitrogen-rich ferrocene derivatives showed remarkable multiresponsive (fluorescent, UV active and redox) Hg2+/Pb2+ sensing properties. Interestingly, the selectivity of L1 and L2 could be switched from Hg2+ to Pb2+ by changing the solvent from CH3OH/H2O (V/V, 1/1) to CH3CN according to UV–vis and fluorescence measurements. L1 and L2 showed highly selective recognition toward Hg2+ in CH3OH/H2O (V/V, 1/1) over a wide range of tested metal ions with a redshift of the absorption bands at approximately 330 nm in their UV–vis absorption spectra. These sensors exhibited immense brightness and remarkable fluorescence quenching following Hg2+ coordination. Interestingly, similar UV responses were induced by adding Pb2+ rather than Hg2+ to the CH3CN solutions of L1 and L2, and remarkable fluorescence enhancements (CHEF = 25 for L1 and 33 for L2) were observed in the presence of Pb2+. Furthermore, each displayed an anodic shift of the redox wave (ΔE1/2 = 0.04–0.15 V) upon complexation with Hg2+ or Pb2+ in CH3CN/CH2Cl2 (V/V, 1/1). Both L1 and L2 formed a 1:1 complex with Hg2+ or Pb2+ through coordination of the two N atoms of the imidazo[4,5-b]pyridine ring, and the PET mechanism was responsible for their fluorescence changes with Hg2+ and Pb2+. When a 3-pyridyl group was introduced, regardless of its position, the selectivity and sensitivity of the sensors for Hg2+ and Pb2+ detection were obviously improved.

Abstract 3922: Proteomic profiling of muscle invasive bladder cancer

Abstract Background: Only one quarter of patients with muscle invasive urothelial bladder cancer (MIBC) gain approximately 5% improvement in 5-year overall survival from cisplatin-based neoadjuvant chemotherapy (NAC). For patients with residual invasive cancer post radical cystectomy there is no standard of care and high mortality. Previous TCGA projects focused on pre-NAC MIBC genomic and transcriptomic alterations and identified 5 molecular subtypes with differential risk and response. For this study we hypothesized that comprehensive proteomic and phosphoproteomic profiling of MIBC prior to NAC will further define mechanisms responsible for chemotherapy resistance, and identify specific and actionable targeted therapies for patients with NAC-resistant tumors. Methods: OCT-embedded and flash frozen tissue samples from 143 eligible patients were processed and tested for proteomics quality control (QC). Samples containing &amp;gt;45% tumor content, less than 10% muscle content and &amp;gt;2,000 protein identifications in a single-shot quality control assay were selected for deep-scale proteomic and phosphoproteomic profiling. A final cohort of 60 samples (52 pre-treatment and 8 patient-matched post-treatment tumors) were multiplexed using tandem mass tags (TMT-11), fractionated by basic reverse phase chromatography and analyzed by liquid chromatography and mass spectrometry (LC-MS). Results: Over 12,000 proteins were identified in total, and 8,353 proteins identified in all samples, including 425 kinases and 77 targets of FDA approved cancer therapies. Principal component analysis identified two distinct resistant clusters and one sensitive cluster. The samples were clustered based on the 5 TCGA subtypes which resulted in the sub stratification of the resistant clusters into two resistance-enriched basal-squamous clusters (BS1 and BS2 respectively), one infiltrated-luminal cluster (L1), one sensitive luminal cluster (L2) and one intermediary cluster (L3) (with 86% samples resistant). UV response, Epithelial to Mesenchymal transition and Myogenesis were significantly elevated in both L1 and L3 (resistant) relative to L2 (sensitive). Similar, these pathways are significantly altered in L1 relative to L3. EGFR, CDK6, ITPKC and CSNK1 were elevated in the B4 subtype, all of which are potentially druggable targets. Matched samples and phosphoproteomics data will be presented. Conclusion: Surrounding non-tumor tissue can obfuscate true tumor signatures in MIBC, cohort selection through stringent pathologic QC allows proteomic profiling to identify tumor features that correlate with NAC resistance. This dataset provides proof of principle that actionable targets and subtype distinctions can be identified through discovery proteomics and further analysis in NAC treated cohorts are justified. Citation Format: Matthew V. Holt, Meggie N. Young, Karoline Kremers, Alexander Saltzman, Antrix Jain, Mei Leng, Hugo Villanueva, Lacey E. Dobrolecki, Beom-Jun Kim, Meenakshi Anurag, Matthew J. Ellis, Anna Malovannaya, Seth P. Lerner. Proteomic profiling of muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3922.

Yttrium (Y) doped ZnO nanowire/p-Si heterojunction devices for efficient self-powered UV-sensing applications

In the current work, n-type Y-doped ZnO nanowires (n-Y:ZnO) and p-type Si heterojunctions are fabricated by employing two-step chemical bath deposition (CBD) process. The work demonstrates the systematic incorporation of Y in ZnO nanowires for achieving the low power UV response. The crystalline nature, morphology, chemical compositions of doped nanowires are studied extensively by employing XRD, FESEM, HRTEM, elemental mapping, EDS and XPS. The change in defect states due to Y incorporation has been studied in detail by using deconvoluated PL spectra. The results indicate that ZnO nanowires exhibit Zn interstitials dependent huge UV/blue luminescence and oxygen vacancy related lowest green luminescence simultaneously for selective 1% Y-doping. The best self-powered photoresponse has been achieved for 1% Y-doped ZnO nanowires/p-Si heterojunction under relatively low power UV illumination (374 nm @5 mW/cm2). More significantly, at self-powered mode, such heterojunction has been delivered a stable and fast (<1 s) photoresponse with a maximum responsivity of 225 mA/W and high On/Off ratio of ∼104. The work provides an insight into the fabrication of heterojunction UV detectors for next-generation self-powered, large area optoelectronic devices.

Work‐Function‐Tunable MXenes Electrodes to Optimize p‐CsCu2I3/n‐Ca2Nb3‐xTaxO10 Junction Photodetectors for Image Sensing and Logic Electronics

AbstractTunable work function has a high profile for the MXene‐based optoelectronic devices, and surface modification provides the huge potential to shift its Fermi level and modulate the work function. In this work, the window of MXene's work function is engineered from 4.55 to 5.25 eV by surface modification with LiF, Se, and polyethylenimine ethoxylated (PEIE). The vertical p‐CsCu2I3/n‐Ca2Nb3‐xTaxO10 junction photodetectors are constructed on the basis of the above surface‐modified MXenes, which changes the Schottky barrier between n‐Ca2Nb3‐xTaxO10 and the electrodes. In particular, the rectification effect is significantly enhanced by utilizing PEIE‐decorated MXene electrodes, resulting in a high rectification ratio of 16 136 and improved UV responsivity of 81.3 A W–1. Such high‐performance devices based on MXenes electrodes are compatible with the standard clean room fabrication process, realizing large‐scale flexible UV detectors that maintain 80% of the original current after 5000 times bending. Meanwhile, a photodetector array stimulated with UV of different wavelengths is constructed to reveal its potential for image sensing. Finally, functional “AND” and “OR” optoelectronic logic gates are developed for UV communication using Au/CsCu2I3/Ca2Nb3‐xTaxO10/MXene–PEIE photodetectors, enriching the application of MXene‐based optoelectronic devices. This work on tuning MXene work function via surface modification demonstrates that MXene is a promising candidate for future optoelectronics.

FABRICATION OF THE P-N JUNCTION ULTRAVIOLET PHOTODETECTORS BASED ON METAL OXIDE NANOPARTICLES

Recently, wide bandgap metal oxides have attracted tremendous attention in the field of UV photodetectors due to their promising optoelectronic properties. Up to now, various approaches have been used to design metal oxide-based UV photodetectors. Among these designs, p-n junction UV photodetectors exhibited remarkable performance. In this study, TiO2/CuCrO2 p-n junction as a UV photodetector was fabricated with spin coating method for the first time. The morphological and optical properties of the fabricated devices were investigated in detail. Moreover, the effect of the CuCrO2 thickness on the performance of the UV photodetector was explored. The fabricated devices showed promising diode behavior and UV response. The responsivity (R) and specific detectivity (D*) of the best device were 3.11 mA/W and 2.37x1011 Jones, respectively at -1.5 V under 3 mW/cm2 light intensity.

Photocatalytic and antibacterial activity of PVA mediated Zinc–Zirconium ferrite composites

In this work, Novel zinc-zirconium ferrite (ZnFe2O4/ZrFe2O5) composite and Zinc ferrite/zirconia (ZnFe2O4/ZrO2) composite were synthesized via coprecipitation technique using Polyvinyl alcohol (PVA) as surfactant. The crystalline structures of the samples were revealed by X-ray diffraction technique. The crystallite sizes were in the range of 50–70 nm. The morphology and elemental composition were studied using scanning electron microscopy, where the zinc ferrite had a truncated octahedral structure with zirconium ferrite decorated on it. The optical properties analyzed through diffuse reflectance spectroscopy and photoluminescence spectroscopy revealed that the samples had good UV and Visible light responses and had oxygen vacancies. The oxygen vacancies enhanced the photocatalytic degradation of methylene blue studied under sunlight and halogen lamp. The vibrating sample magnetometer (VSM) analysis corroborates the ferrimagnetic nature of the composites. The antibacterial activity against Escherichia coli and Staphylococcus aureus was also examined and compared with the commercial antibiotic, amikacin, and other ferrite-composites reported.

Simultaneous relative UV response determination of known liquid drug product degradants by NMR spectroscopy

Determination of impurity level in weight percent against the claimed active pharmaceutical ingredient (API) in a drug product is of critical importance in drug development. However, authentic material used to determine relative UV response factor (RRF) for impurity quantitation is sometimes not available or not stable. In a particular drug product liquid formulation, three degradants, including one unstable impurity, are consistently observed in stability studies. Here we describe the application of NMR spectroscopy to assist in the determination of RRFs, simultaneously, for all three degradants directly from degraded drug product extracts. This technique was not only effective in determining RRF of an unstable substance, but also in defining RRFs of multiple degradants from a single drug product sample. Overall, this study continues to demonstrate the capabilities of NMR for impurity quantitation in drug development.