Shift Of Absorption Peak Research Articles

Acceptor-donor-acceptor-type molecules with large electrostatic potential difference for effective NIR photothermal therapy.

Although acceptor-donor-acceptor (A-D-A)-type molecules offer advantages in constructing NIR absorbing photothermal agents (PTAs) due to their strong intramolecular charge transfer and molecular planarity, their applications in photothermal therapy (PTT) of tumors remain insufficiently explored. In particular, the influence of ESP distribution on the optical properties of A-D-A photosensitizers has not been investigated. Herein, we analyze and compare the difference in ESP distribution between A-D-A-type small molecules and polymers to construct NIR absorbing PTAs with a high extinction coefficient (ε) and high photothermal conversion efficiency (PCE). The calculation results of density functional theory (DFT) indicate that the large ESP difference makes A-D-A-type small molecules superior to their polymer counterparts in realizing tight molecular packing and strong NIR absorbance. Among the as-prepared nanoparticles (NPs), Y6 NPs exhibited an obvious bathochromic shift of absorption peak from 711 nm to 822 nm, with the NIR-II emission extended to 1400 nm. Moreover, a high ε value of 5.69 L g-1 cm-1 and a PCE of 66.3% were attained, making Y6 NPs suitable for PTT. With a concentration of 100 μg mL-1, Y6 NPs in aqueous dispersion yielded a death rate of 93.4% for 4T1 cells upon 808 nm laser irradiation (1 W cm-2) for 10 min, which is comparable with the best results of recently reported PTT agents.

Preparation and Characterization of Homogeneous Blend of Dietary Fiber and Starch Based on Ionic Liquids

AbstractIn this study, a homogeneous blend of starch and dietary fiber (DF), which contained both water‐soluble and water‐insoluble compositions, is prepared in ionic liquids. The morphology and structure of the regenerated blend are studied using a scanning electron microscope (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), and thermogravimetric analysis (TGA). It is found that the morphological structures of both original starch and DF are destroyed, and a homogeneous morphological structure is formed for the blend during the dissolution‐regeneration process in ionic liquids. Though no new chemical combination is observed from the infrared spectrum of the regenerated blend, the shift of absorption peaks appeared due to the destruction of the hydrogen bond during the dissolution of ionic liquids. The XRD results showed that the regenerated blend showed a disordered structure which is different from the orderly crystalline structure of original starch and DF. The disordered structure may result in the reduction of thermal stability. Among three ionic liquids 1‐allyl‐3‐methylimidazole chloride ([AMIM]Cl), 1‐ethyl‐3‐methylimidazole chloride ([EMIM]Cl), and 1‐ethyl‐3‐methylimidazole acetate ([EMIM]OAc), [EMIM]Cl has the best solubility to the blend and also has the most disruptive to the native structure of starch and DF, correspondingly.

Effect of Zn/S/TGA concentration on the stability and optical properties of TGA capped ZnS quantum dots synthesized via one pot aqueous synthesis method

Aqueous ZnS quantum dots (QDs) were synthesised via a facile, cost-effective one-pot synthesis method in the ambient environment. To achieve most favourable ratios of thioglycolic acid (TGA):zinc (Zn):sulphide (S), the concentration optimisation by optical spectra (COOS) method was adopted. The x-ray diffraction (XRD) spectra confirmed the zinc-blende (cubic) phase of ZnS quantum dots (QDs), and Scherrer’s method determined that on average, the QDs exhibit a size of 2 nm. The Fourier-transform infrared spectroscopy (FTIR) study shows that characteristic peaks are consistent with the vibrational modes of the TGA ligands, confirming the capping. The quantum dots (QDs) synthesised displayed a significant effect of quantum confinement with blue shift in absorption peaks, compared with bulk ZnS absorption peak. Interestingly, on increasing the concentration of TGA, it resulted in red shift at the absorption edge, shifting from 300 nm to 314 nm. On the other hand, increasing the concentration of cation Zn and anion S ratio led to a blue shift, ranging from 315 to 295 nm, and a red shift, ranging from 280–320 nm, at absorption edges respectively. A prominent emission peak appeared at 428 nm. The application of Brus equation allowed estimating the size of the quantum dots (QDs) to be within the range of 2 to 2.7 nm, which correlated well with the Bohr’s radius of ZnS. This favourable property proposes the use of QDs in various optoelectronic devices.

Enhancement of graphitic carbon nitride (g‐C3N4) assisted photodegradation of Rhodamine B under visible light

AbstractIn the current work, the g‐C3N4 photocatalyst was produced by thermal polycondensation of melamine. The Characterization techniques XRD, SEM, FTIR, UV‐DRS, PL, and BET were investigated to find out inherent properties. The PL spectra of the g‐C3N4 photocatalyst showed good absorbance in visible regions for faster degradation of Rhodamine B (RhdB). The synthesized g‐C3N4 photocatalyst is employed for decolorization and demineralization of RhdB about 73 % and 80 % in 105 min and 480 min under visible light. Further, the addition of H2O2 and H2SO4 to RhdB solution in the presence of g‐C3N4 showed enhanced results when compared to g‐C3N4 alone. Moreover, it reduces the time for the removal of RhdB. Simultaneously impeding shift of the maximum absorption peak of RhdB represents alteration of the degradation mechanism. Under alike conditions of photodegradation, after the addition of H2O2 and H2SO4 to the dye solution. The removal of RhdB is enhanced to 98 % and 95 % in 40 min, and 60 min for 5 mg/l and 10 mg/l respectively for H2O2. Further, the addition of H2SO4 enhances efficiency up to 87 %, and 95 % in 50 min, and 80 min respectively for 5 mg/l and 10 mg/l. The overall H2O2 addition showed better efficiency and better rate constants.

Regulating the band gaps of seven stacking patterns of bilayer hexagonal boron nitrides by doping carbon atoms in opposite sites

The band gaps of seven stacking patterns of bilayer hexagonal boron nitrides(h-BNs) are regulated by changing the doping positions of carbon atoms using density functional theory calculations. The calculation results dwell on that the AA1 stacking pattern h-BN has the largest band gap among seven stacking patterns of h-BNs. The influences of five different doping positions of carbon atoms to the band gap of AA1 stacking pattern bilayer h-BN are investigated and the results shows that the opposite doping model has the largest band gap decline among five doping configurations under the same doping content. As for the other four doping models, the calculation results illustrate that the adjacent doping model is the most stable configuration, the remote doping configuration makes the planar construction of bilayer h-BN destroyed and the two cases of alternate doping configurations present metal properties. Therefore, the opposite doping model is the most valuable doping configuration. Bilayer h-BN transformed from insulating state to semiconductor state and the optical absorption coefficient of it shows that the absorption peak shifts to longer wavelength range after doping carbon atoms into opposite sites. Density of states and electron densities results indicate that the main reason of band gap decline is the charge transfer among atoms. This research should be helpful for designing band gaps of h-BN bilayers in nano- electronics applications.

Dual signal AA detection based on fluorescence and local surface plasmon resonance absorption technology

The core/shell Au@MnO2 nanoparticles (Au@MnO2 NPs) were prepared and characterized by UV–vis spectrum, transmission electron microscopy (TEM) and X-ray photoelectron spectrum (XPS). It was found that MnO2 in the shell of Au@MnO2 NPs could oxidize thiamine (VB1) into blue fluorescent thiochrome (TC). The reduction of MnO2 in the shell layer could lead to a decrease of Au@MnO2 NPs size along with a blue shift of the localized surface plasmon resonance (LSPR) peak. Once ascorbic acid (AA) was introduced, MnO2 in the shell was rapidly reduced to Mn2+ ions. Accordingly, the oxidation of VB1 was inhibited and the fluorescence of TC was weakened. Based on these phenomena, we have established a dual signal method for AA determination with the help of UV–vis and fluorescence spectrophotometer. Under the optimum conditions, the LSPR absorption peak shift (Δλ) of Au@MnO2 NPs and the decrease in fluorescence of TC correlated well with AA concentration ranging from 0.75 to 17.5 μM. The detection limits of LSPR absorption assay and fluorescence assay were 0.18 and 0.47 μM, respectively. More importantly, this dual-signal detection method has been used for the determination of AA in vitamin C tablets with high accuracy and precision, indicating its promising potential applications.

Chemical Detoxification of Therapeutic Hybrid Complexes Prepared by the Compatible Combination of Ayurvedic Herb and Allopathic Drug

Background & Objective: The treatment of diseases and good health maintenance are the common fundamental aims of ayurvedic and allopathic medical systems. Limited information is available in the public domain for the concept of symbiohealth, i.e., the symbiotic interaction of ayurveda and allopathy, that needs to be explored for an efficient and robust health system. Therefore, an attempt has been made to reduce the toxicity of therapeutic drugs via the integration approach of ayurveda and allopathy. Methods: Three different categories of allopathy and ayurvedic medicines, such as antacids (omeprazole, ranitidine, and sooktybhasma), antibacterial (amoxicillin trihydrate, ciprofloxacin hydrochloride, Curcuma longa, and Datura stramonium) and antiviral (acyclovir, efavirenz, Echinacea, Calendula, Allium sativum, and Citrullus colocynthis) were targeted. Results: Best therapeutic hybrid combination was obtained on the basis of their UV absorption maxima and peak shift. Acyclovir with A. sativum (1-6%), sooktybhasma 20% with rantidine, Ciprofloxacin HCl (2%) with 10% aqueous datura and Ciprofloxacin HCl (0.02-0.2%) with 0.02-0.06% acetonitrile turmeric showed best integration result. This drug integration can be applied to improve the potential results or detoxification of hybrid drugs that target the drug moiety results in reduced side effects or the dose of important drugs, which might be due to the chelation pattern of their functional group, absorption, bonding, and pi-pi interaction. Conclusion: This study will provide the leadership for the betterment of a therapeutic hybrid drug complex that might be useful as an allopathic drug and less harmful than its ayurvedic component. The proposed integration fusion of different medication therapies, such as Ayurvedic and allopathic, has the potential for a scientific merger.

Co(II)-TiO2/Ti Thin Film as Antibacterial Photocatalysts Escherichia Coli Under Visible Light Ilumination

A thin layer of TiO2 doped with Cobalt (II) immobilized on the surface of a titanium foil (Co(II)-TiO2/Ti) has been synthesized from a titanium foil (Ti) as a TiO2 precursor as well as a thin layer matrix and CoCl2.6H2O as a source of Co(II) on variations of 0.5%, 1% and 2%. Synthesis was carried out by anodizing method using ethylene glycol electrolyte solution with the addition of NH4F and followed by calcination treatment at 450ºC for 3 hours. The obtained Co(II)-TiO2 /Ti thin films were characterized using Fourier-transform infrared (FT-IR) spectroscopy, Diffuse Reflectance UV-Vis (DRSUV-Vis) and X-ray diffraction (XRD) methods. Doping Co(II) variations of 0.5%, 1.0% dan 2.0% in the TiO2 structure causes a shift in the vibrational absorption peak of Ti-O (460.99 cm-1) towards a smaller wave number of 459.06 cm-1 respectively ; 453.27 cm-1 and 451.34 cm-1. This is supported by the results of the DRUV-Vis analysis using the tauc plot method, which shows a decrease in the band gap energy of TiO2 (3.24 eV) to 2.57 eV, 2.47 eV and 2.28 eV. Based on XRD analysis, it is known that the Co(II)-TiO2/Ti photocatalyst has anatase phase with a crystal size of 15-17 nm. The photocatalytic activity of Co(II)-TiO2/Ti under visible light illumination was evaluated for inhibition of Escherichia coli bacterial growth. Co(II)-TiO2/Ti photocatalyst at 2.0% Co(II) concentration had the best inhibition (43.2%) compared to 0.5% and 1.0% Co(II) concentrations, respectively 18% inhibition and 27%.

SINTESIS GEOPOLIMER DENGAN BAHAN DASAR KAOLIN CAPKALA SEBAGAI ADSORBEN ION Pb(II) DALAM LARUTAN (SYNTHESIS OF GEOPOLYMERS WITH BASE MATERIALS KAOLIN CAPKALA AS ADSORBENT ION Pb(II) IN SOLUTION)

Geopolymer synthesis was carried out using kaolin, for the adsorption of Pb (II) ions in solutions. Kaolin is used by Kaolin Capkala from Bengkayang Regency, West Kalimantan. This kaolin was first modified into metakaolin. The scaling up of geopolymers is carried out by making an activating solution, namely by mixing NaOH and Na2SiO3. The activating solution is mixed into metakaolin. The mass composition of each component in the geopolymer: metakaolin of 94,5 grams, Na2SiO3 of 57 grams, NaOH of 12 grams, and H2O of 30 grams. The formed geopolymers are tested for their adsorption ability against Pb(II) ions. The research results show the success of geopolymer formation as indicated by FTIR and XRD characterization results. Based on the FTIR results, several indications of successful geopolymer formation are seen in the shift and widening of the Si-O absorption peak at wave number 1109 cm-1 for kaolin to 1058 cm-1 for metakaolin and 1016 cm-1 for geopolymer; the appearance of O-C-O bond absorption in CO32- at 1362 cm-1 in geopolymer; and a shift in absorption of Al-O (Al (VI), wherein kaolin it is indicated by a wave number of 536 cm-1 while in metakaolin it is characterized by a wave number of 544 cm-1 and for geopolymer a wave number of 553 cm-1 indicates it. XRD diffractogram of the formation hump's appearance shows the amorphous characteristics of metakaolin and geopolymer at around 2θ 26o-35o. The application of geopolymer for Pb adsorption shows that Pb(II) can be adsorbed well in geopolymers with the maximum adsorption capacity of 2.77 mg/ g obtained at various concentrations of 40 ppm.

Sound absorption performance of composite structures from a kind of lightweight ceramic foam with perforated plate

PurposeThe purpose of this paper is mainly to know: (1) the sound absorption coefficient of porous composite structures constituted by a new kind of lightweight ceramic foam and perforated plate; (2) the availability of an equivalent porous material model, recently proposed by the present author, to these composite structures in sound absorption.Design/methodology/approachA kind of lightweight ceramic foam with bulk density of 0.38–0.56 g·cm-3 was produced by means of molding, drying and sintering. The effect of stainless steel perforated plate on sound absorption performance of the ceramic foam was investigated by means of JTZB absorption tester.FindingsThe results indicate that the sound absorption performance could be obviously changed by adding the stainless steel perforated plate in front of the porous samples and the air gap in back of the porous samples. Adding the perforated plate to the porous sample with a relatively large pore size, the sound absorption performance could be evidently improved for the composite structure. When the air gap is added to the composite structure, the first absorption peak shifts to the lower frequency, and the sound absorption coefficient could increase in the low frequency range.Originality/valueBased on the equivalent porous material model and the “perforated plate with air gap” model, the sound absorption performance of the composite structures can be simulated conveniently to a great extent by using Johnson-Champoux-Allard model.

Optical properties of methyl-substituted germanane monolayer in the presence of the external magnetic field, strain and spin-orbit coupling.

In this research, we use the tight-binding model, which includes spin-orbit coupling and an external magnetic field, to describe the optical properties of the methyl-substituted germanane (GeCH3) monolayer. We have applied the Kubo formula, linear response theory, and Green's function approach to calculate the optical absorption coefficient of the GeCH3monolayer. Here, the effects of an external magnetic field, strain, spin-orbit coupling, temperature, and electron/hole doping on the frequency dependence behavior of the optical conductivity have been investigated in detail. Our numerical results show that with increasing the external magnetic field, strain, and electron doping, the weight of the Drude increases. The optical absorption peak decreases and shifts to higher frequencies by applying an external magnetic field, strain, and electron doping. Controlling the optical and electronic properties of GeCH3is leading to use this structure it in the electronic and optoelectronic industries.

Dual-mode cholesterol sensor based on gold nanorods and carbon quantum dots

A novel dual-mode cholesterol biosensor was developed based on gold nanorods-carbon quantum dots-Cholesterol oxidase (AuNRs-CQDs-COD) complex synthesized by the cross-linking method. The specific reaction to/against cholesterol and cholesterol oxidase can produce hydrogen peroxide. Due to the etching effect between the hydrogen peroxide and AuNRs, the absorption peaks of AuNRs would drift so that the fluorescence quenching occurred because of the electronic charge transfer between the hydrogen peroxide and CQDs. The spectrum properties, structure and micromorphology of AuNRs-CQDs-COD complex were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR), Fluorescence and Ultraviolet–Visible absorption spectroscopy, respectively. There was a good linear correlation between the fluorescence response and absorption peak shift of AuNRs-CQDs-COD probe in cholesterol solution within the concentration in the range 0.1–1 mM, and the limit of detection (LOD) is 0.028 μM. This dual-mode cholesterol biosensor based on AuNRs-CQDs-COD complex has good anti-interference and selectivity.

Optimizing BiOCl concentration for enhanced LDPE performance: Investigation of structure, thermal stability, and optical characteristics

This research article presents a comprehensive study on enhancing the structural, thermal alongside optical properties of LDPE by incorporating BiOCl nanoparticles. LDPE nanocomposites were synthesized using the solvent casting technique, employing different concentrations of BiOCl (3, 5, and 7 wt.%) nanoparticles. BiOCl demonstrated crystalline anisotropic growth along the (110) plane under solvothermal treatment, enhancing the interfacial interaction with LDPE chains. This interaction reduces electrostatic inter-chain interactions, promoting alignment and crystallization of molecular chains and yielding a smooth morphology. The optimal BiOCl concentration is determined to be 5 wt.%, as higher concentrations lead to nanoparticle aggregations and weak interactions. Raman spectroscopy shows broadened intensity peaks in the nanocomposite with increasing BiOCl concentrations, indicating the presence of defects and oxygen vacancies. These findings offer promising prospects for photocatalytic applications. The thermal analysis reveals enhanced thermal stability, fire resistance, and insulation in the nanocomposites compared to pure LDPE. The incorporation of BiOCl increases activation energy, melting, and glass transition temperatures, highlighting their positive impact on enhancing the thermal properties of LDPE. The red shift in absorption peaks of LDPE nanocomposites indicates π-delocalization, suggesting small band gaps. Additionally, higher weight percentages of BiOCl nanoparticles in the LDPE matrix result in increased absorption intensities in the UV region, providing enhanced UV radiation protection, with a maximum absorption of 96% of UV light. The results include improved interaction, morphology, alignment, thermal stability, fire resistance, and UV protection of BiOCl: LDPE nanocomposite, with potential for diverse industries.

Phage-targeting bimetallic nanoplasmonic biochip functionalized with bacterial outer membranes as a biorecognition element

The use of phages—a natural predator of bacteria—has emerged as a therapeutic strategy for treating multidrug-resistant bacterial infections; thus, the isolation and detection of phages from the environment is crucial for advancing phage therapy. Herein, for the first time, we propose a nanoplasmonic-based biodetection platform for phages that utilizes bacterial outer membranes (OMs) as a biorecognition element. Conventional biosensors based on phage-bacteria interactions encounter multiple challenges due to the bacteriolytic phages and potentially toxic bacteria, resulting in instability and risk in the measurement. Therefore, instead of whole living bacteria, we employ a safe biochemical OMs fraction presenting phage-specific receptors, allowing the robust and reliable phage detection. In addition, the biochip is constructed on bimetallic nanoplasmonic islands through solid-state dewetting for synergy between Au and Ag, whereby sensitive detection of phage-OMs interactions is achieved by monitoring the absorption peak shift. For high detection performance, the nanoplasmonic chip is optimized by systematically investigating the morphological features, e.g., size and packing density of the nanoislands. Using our optimized device, phages are detected with high sensitivity (≥∼104 plaques), specificity (little cross-reactivity), and affinity (stronger binding to the host OMs than anti-bacterial antibodies), further exhibiting the cell-killing activities.

Formation of whey protein isolate–dextran conjugates by Maillard reaction with ethanol-water pretreatment

A simple, efficient, and low-cost Maillard reaction method was developed through ethanol-water pretreatment. The formation of whey protein isolate (WPI)–dextran conjugates was confirmed using the degree of glycosylation, ultraviolet absorbance, browning intensity, color, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The significant conformational changes were illuminated because of the higher wavenumber shift of absorption peaks of FTIR amide I, II, and III bands, the reduction of fluorescent signal, and the decrease of surface hydrophobicity. Scanning electron microscopy revealed the morphological transition of WPI from a smooth sphere to an inhomogeneous block structure with rough and uneven surface before and after covalent grafting of dextran. The strong steric hindrance and abundant hydrophilic hydroxyl groups from covalently conjugated dextran dramatically inhibited the aggregation between conjugate molecules which exhibited low turbidity and good solubility in a wide pH range from 2.0 to 10.0. Emulsifying activity and emulsifying stability of WPI were significantly improved after glycosylation. This work will be beneficial to control the formation of light-colored Maillard reaction products under high substrate concentration, high reaction rate, and low water content at mild temperatures for short processing time, and to facilitate the large-scale preparation of glycosylated protein with desirable physicochemical properties.

The Role of Virgin Coconut Oil in Corn Starch/NCC-Based Nanocomposite Film Matrix: Physical, Mechanical, and Water Vapor Transmission Characteristics.

Corn starch-based nanocomposite films usually have low moisture barrier properties. Adding virgin coconut oil (VCO) as a hydrophobic component can improve the nanocomposite film's characteristics, especially the film's permeability and elongation properties. This study aimed to determine the role of VCO with various concentrations (0, 3, 5 wt%) on the physical, mechanical, and water vapor transmission characteristics of corn starch/NCC-based nanocomposite films. Adding 3% VCO to the film showed the lowest WVTR value by 4.721 g/m2.h. At the same time, the value of tensile strength was 4.243 MPa, elongation 69.28%, modulus of elasticity 0.062 MPa, thickness 0.219 mm, lightness 98.77, and water solubility 40.51%. However, adding 5 wt% VCO to the film increased the film's elongation properties by 83.87%. The SEM test showed that adding VCO formed a finer structure with pores in several areas. The FTIR films showed that adding VCO caused a slightly higher absorption peak shift at the O-H groups and new absorption peaks at wave numbers 1741 cm-1 and 1742 cm-1. The results of this study may provide opportunities for the development of nanocomposite films as biodegradable packaging in the future.

Development of Nano-Micro Fused LSPR Chip for In Situ Single-Cell Secretion Analysis.

Single-cell analysis has become increasingly important in uncovering cell heterogeneity, which has great implications in medicine and biology for a deep understanding of cell characteristics. Owing to its significance, it is vital to create novel devices that can reveal special or unique cells. In this work, we developed a single-cell secretion detection chip consisting of microwells that can trap single cells. Each well is surrounded by Au nanopillars capable of localized surface plasmon resonance (LSPR) measurement. Using microfabrication and nanofabrication techniques, Au nanopillar and microwell structures were fabricated on a COP film. The Au nanopillar was modified with IL-6 antibodies for the direct detection of single-cell secreted IL-6 via LSPR absorbance peak shift. Specific IL-6 detection was successfully demonstrated using a null and IL-6 oversecreting Jurkat cell. A high single-cell trapping efficiency of over 80% was also achieved. Overall, the development of this single-cell secretion detection chip with a simple LSPR measurement setup represents a significant development in the field of cell biology and immunology, providing researchers with a powerful tool for studying individual cells and their secreted cytokines, and is useful for point-of-care testing (POCT) diagnostics.

Application of Localized Surface Plasmon Resonance of Conjugated Gold Nanoparticles in Spectral Diagnosis of SARS-CoV-2: A Numerical Study.

Severe respiratory syndrome COVID-19 (SARS-CoV-2) outbreak has became the most important global health issue, and simultaneous efforts to fast and low-cost diagnosis of this virus were performed by researchers. One of the most usual tests was colorimetric methods based on the change of color of gold nanoparticles in the presence of viral antibodies, antigens, and other biological agents. This spectral change can be due to the aggregation of the particles or the shift of localized surface plasmon resonance due to the electrical interactions of surface agents. It is known that surface agents could easily shift the absorption peak of metallic nanocolloids which is attributed to the localized surface plasmon resonance. Experimental diagnosis assays for colorimetric detection of SARS-CoV-2 using Au NPs were reviewed, and the shift of absorption peak was studied from the viewpoint of numerical analysis. Using the numerical method, the refractive index and real and imaginary parts of the effective relative permittivity of the viral biological shell around Au NPs were obtained. This model gives a quantitative description of colorimetric assays of the detection of SARS-CoV-2 using Au NPs.

Synthesis of Ni doped-TiO2 Thin Film Photocatalysts on Glass Surfaces

Thin film of TiO2 modified Ni2+ cationic (Ni doped-TiO2) thin films were synthesized from titanium tetraisopropoxide (TTIP) and Ni(NO3)2.6H2O using the combined sol-gel and dip coating method followed by calcination at 500oC for an hour. This study aims to determine the concentration of Ni2+ and the optimum number of layers for application as self-cleaning. Frontier transform infrared (FTIR) spectrophotometric analysis observed a shift in the vibration absorption peak of Ti-O towards a smaller wave number as an indication that the Ni2+ cationic have incorporated in the TiO2matrix in forming Ni-TiO2. Based on the of x-ray diffraction (XRD) it is known that Ni-TiO2 has anatase crystalline phase with a crystallite size of 149.20 nm. Diffuse reflectance ultraviolet-visible (DRSUV-Vis) spectrophotometry showed a decrease in the bandgap energy (3.2 eV to 2.22 eV). Surface morphological by scanning electron microscopy (SEM) method showed that the addition of polyethylene glycol (PEG) resulted in a more homogeneous distribution of particles than thin films without PEG. The self-cleaning activity of Ni-TiO2 was tested for surface hydrophilic properties by measuring the contact angle of water and oil droplets under visible light illumination.

Poly(3-amino-carbazole) derivatives containing 1,10-phenanthroline and 8-hydroxyquinoline ligands: Synthesis, properties and application as ion sensors

As we know, excessive metal ions can even damage human health. Herein, two novel kinds of fluorescent sensing materials Poly(3-amino-carbazole) derivatives containing 1,10-phenanthroline and 8-hydroxyquinoline were synthesized and further applied to fluorescence detection for ions. The results show that Ni2+, Cu2+, and Pd2+ have excellent quenching effects on the fluorescence of Poly[9-(1,10-phenanthroline-2-yl)-9H-carbazol-3-amine] (PPNC), the LOD for these ions reaches 5.2 nM, 12.7 nM, 33.5 nM respectively. In the process of ion response, there is no shift of UV absorption peak, combined with IR spectra and theoretical calculation simulation, the quenching is considered to be caused by the coordination between metal ions and the second amine (–NH-) or 1,10-phenanthroline ligand of PPNC, which leads to the charge transfer from ligands to metal ions. In addition, an acid test was done for PPNC to verify and detect the presence of secondary amine (–NH-), and the results show that PPNC has good acid sensing ability which also supports the secondary amine (–NH-) structure. Finally, the paper test was performed on PPNC, indicating that PPNC has the potential for visual application.