In the last decade, researchers have been searching for innovative platforms, methods, and techniques able to address recurring problems with the current cancer detection methods. Early disease detection, fast results, point-of-care sensing, and cost are among the most prevalent issues that need further exploration in this field. Herein, studies are focused on overcoming these problems by developing an electrochemical device able to detect telomerase as a cancer biomarker. Electrochemical platforms and techniques are more appealing for cancer detection, offering lower costs than the established cancer detection methods, high sensitivity inherent to the technique, rapid signal processing, and their capacity of being miniaturized. Therefore, Au interdigital electrodes and electrochemical impedance spectroscopy were used to detect telomerase activity in acute T cell leukemia. Different cancer cell concentrations were evaluated, and a detection limit of 1.9 × 105 cells/mL was obtained. X-ray photoelectron spectroscopy was used to characterize the telomerase substrate (TS) DNA probe self-assembled monolayer on gold electrode surfaces. Atomic force microscopy displayed three-dimensional images of the surface to establish a height difference of 9.0 nm between the bare electrode and TS-modified Au electrodes. The TS probe is rich in guanines, thus forming secondary structures known as G-quadruplex that can be triggered with a fluorescence probe. Confocal microscopy fluorescence images showed the formation of DNA G-quadruplex because of TS elongation by telomerase on the Au electrode surface. Moreover, electrodes exposed to telomerase containing 2',3'-dideoxyguanosine-5'-triphosphate (ddGTP) did not exhibit high fluorescence, as ddGTP is a telomerase inhibitor, thus making this device suitable for telomerase inhibitors capacity studies. The electrochemical method and Au microchip device may be developed as a biosensor for a point-of-care medical device.

In this work, we designed and synthesized a special axle guest hexyldimethyl(ferrocenylmethyl)ammonium (1 + ) bromide. The binding interactions of 1 + and its oxidized form 1 2+ with cucurbit[7]uril (Q[7]) and cyclohexanocucurbit[6]uril (Cy6Q[6]) were investigated by 1H NMR, cyclic voltammogram, and isothermal titration calorimetry techniques. Our data indicate that both hosts Cy6Q[6] and Q[7] can form stable [2]pseudorotaxanes with 1 + in their different redox states. Most importantly, the combination and dissociation of the hosts with the guest as well as the binding location can be controlled by electrochemical means, which develops a special molecular switch and selector.

Nucleic acid tests integrated into digital point-of-care (POC) diagnostic systems have great potential for the future of health care. However, current methods of DNA amplification and detection require bulky and expensive equipment, many steps, and long process times, which complicate their integration into POC devices. We have combined an isothermal DNA amplification method, recombinase polymerase amplification, with an electrochemical stem-loop (S-L) probe DNA detection technique. By combining these methods, we have created a system that is able to specifically amplify and detect as few as 10 copies/μL Staphylococcus epidermidis DNA with a total time to result of 70-75 min.

In this paper, we report a simple two-step approach for the synthesis of large graphene oxide (GO) sheets with lateral dimensions of ≈10 μm or greater. The first step is a pretreatment step involving electrochemical exfoliation of graphite electrode to produce graphene in a mixture of H2SO4 and H3PO4. The second step is the oxidation step, where oxidation of exfoliated graphene sheets was performed using KMnO4 as the oxidizing agent. The oxidation was carried out for different times ranging from 1 to 12 h at ∼60 °C. Prepared GO batches were characterized using a number of spectroscopy and microscopy techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-visible spectroscopy. Raman and thermogravimetric analysis techniques were used to study the degree of oxidation in the as-synthesized GO batches. The UV-visible absorption spectrum showed an intense peak at 230 nm and an adjacent band at 300 nm corresponding to π-π* and n-π* transitions in all samples. Normalized FTIR plots were used to calculate the relative percentages of oxygen-containing functional groups, which were found to be maximum in GO (6 h). Boehm titration was used to quantify the functional groups present on the GO surface. Overall GO sheets obtained after 6 h of oxidation, GO (6 h), were found to be the best. XRD pattern of GO (6 h) revealed a characteristic peak at 2θ = 8.88°, with the corresponding interplanar spacing between the layers being 0.995 nm, which is among the best with respect to the previous methods reported in the literature. Raman spectroscopy showed that the degree of defect (I D/I G) area ratio for GO (6 h) was 1.24, which is higher than that obtained for GO (1.18) prepared by widely used Marcano's approach.

Tafel analysis and electrochemical impedance spectroscopy (EIS) have been widely used to characterize many kinds of electrocatalysts. The former provides the kinetic information of an electrochemical reaction with the exchange current while the latter does with the charge transfer resistance closely related to the exchange current. Both techniques, however, suffer from practical troubles which often decrease their reliabilities. In order to circumvent those troubles, an alternative was suggested that Tafel analysis was combined with EIS, even though its theoretical background was not clearly established. Tafel analysis is based on dc measurement, and EIS is on an ac one, respectively. Here, inspired by the second generation of EIS from chronoamperometry, we try to find how those techniques are correlated by investigating an amperometric response from EIS. The first step is Fourier transform of an arbitrary dc potential signal in the time domain to obtain the amplitudes and phases of the Fourier series which are equivalent to ac signals of each frequency. Second, with the Fourier series being applied onto the impedance data, the responding currents of each frequency are calculated by Ohm's law. Third, the current in the frequency domain is transferred back to the time domain by inverse Fourier transform to yield chronoamperometric or Tafel plots depending on the type of the applied dc potential. Finally, we can study Tafel plots based on EIS at different conditions and their correlations which are expected to be a better indicator for characterizing electrocatalysts instead of the slope of the classical Tafel analysis.

Getters are among the key functional components in the tritium-producing burnable absorber rods (TPBARs) of light water reactors (LWRs) and are used to capture the released tritium gas. They are nickel-plated zircaloy-4 tubes that, upon exposure to irradiation or tritium in the light water reactors, undergo alteration in structure, chemical composition, and chemistry. Understanding the radial tritium distribution is key to gaining insight into the evolution of new chemistry upon irradiation to predict getter performance. The holy grail is to develop a method akin to selectively peeling off the layers of an onion in an effort to get a radial map of elements and particularly tritium across the getter. Toward this goal, the overall aim of this work is to establish a correlative technique that can be used to determine radial tritium distribution across getters. To this end, this work specifically focuses on the validation of a correlative method for controlled radial dissolution of nickel-plated getters. Here, pristine getters as well as getters loaded with different mass ratios of hydrogen and deuterium are used as the nonradioactive surrogates of tritium, the idea being that the methodology can be readily extended to tritiated getter components. Here, the surface nickel layers as well as the bulk zirconium layers are sequentially dissolved in a controlled, uniform way using voltage-assisted electrochemical dissolution techniques. The dissolution is complemented by periodic elemental analysis of the electrolyte solution during and post dissolution. This is complemented by microscopic analyses on the exposed surfaces to provide a correlative technique for a complete picture of the radial distribution of various elements across the getter.

Three, PO4 3-/HPO4 2- and AsO4 3--incorporated, new tetranuclear complexes of copper(II) and zinc(II) ions have been synthesized and fully characterized. In methanol-water, reactions of H3cpdp (H3cpdp = N,N'-Bis[2-carboxybenzomethyl]-N,N'-Bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol) with copper(II) chloride in the presence of either NaOH/Na2HPO4·2H2O or KOH/Na2HAsO4·7H2O lead to the isolation of the tetranuclear complexes Na3[Cu4(cpdp)2(μ4-PO4)](OH)2·14H2O (1) and K2[Cu4(cpdp)2(μ4-AsO4)](OH)·162/3H2O (2), respectively. Similarly, the reaction of H3cpdp with zinc(II) chloride in the presence of NaOH/Na2HPO4·2H2O yields a tetranuclear complex, Na(H3O)2[Zn4(cpdp)2(μ4-HPO4)]Cl3·121/2H2O (3). All complexes are characterized by single-crystal X-ray diffraction and other analytical techniques, such as Fourier transform infrared and UV-vis spectroscopy, thermogravimetric and electrochemical studies. The solid-state molecular framework of each complex contains two monocationic [M2(cpdp)]+ (M = Cu, Zn) units, which are exclusively coordinated to either phosphate/hydrogen phosphate or arsenate groups in a unique mode. All three complexes exhibit a μ4:η1:η1:η1:η1 bridging mode of the PO4 3-/HPO4 2-/AsO4 3- groups, with each bridging among four metal ions. The thermal properties of all three complexes have been investigated by thermogravimetric analysis. Low-temperature magnetic studies of complexes 1 and 2 disclose moderate antiferromagnetic interactions mediated among the copper centers through alkoxide and phosphate/arsenate bridges. Electrochemical studies of complexes 1 and 2 in dimethylformamide using cyclic voltammetry reveal the presence of a fairly assessable one-electron metal-based irreversible reduction and one quasireversible oxidation couple.

The present work describes the synthesis of Ag-CoFe2O4/rGO nanocomposite as a photocatalyst through the hydrothermal process by the attachment of silver and cobalt ferrite (CoFe2O4) nanoparticles on the surface of reduced graphene oxide. The effect of Ag and reduced graphene oxide (rGO) on the structure, optical, magnetic, photocatalytic, and electrochemical performance of the CoFe2O4 is systematically explored through various analytical techniques. The analyses of the observed outcomes reveal that the graphene sheets are exfoliated and decorated with well-dispersed Ag and CoFe2O4 nanoparticles. UV-vis spectra indicate a gradual shift in the absorption edge toward the higher wavelength with the addition of Ag ions, which signifies variation in the energy gap of the samples. Photoluminescence results divulge that graphene can decline the electron-hole recombination rate and improve the photocatalytic activity of the Ag-CoFe2O4/rGO nanocomposite. In this context, the Ag-CoFe2O4/rGO sample presents good catalytic activity as compared to the CoFe2O4 and Ag-CoFe2O4 photocatalysts for the degradation of methylene blue (MB) dye and suggests that the rGO plays a vital role in the Ag-CoFe2O4/rGO nanocomposite. The deterioration rate of the samples is found to be in the order of CoFe2O4(78.03%) < Ag-CoFe2O4(83.04%) < Ag-CoFe2O4/rGO(93.25%) in 100 min for MB dye, respectively, under visible-light irradiation. The room-temperature ferromagnetic behavior of the samples is confirmed by the M-H hysteresis loop measurements. Overall, the Ag-CoFe2O4/rGO nanocomposite promises to be a strong magnetic photocatalyst for contaminated wastewater treatment. The electrochemical performance of all of the samples was examined by the cyclic voltammetry (CV) that exhibits a superior rate performance and cycle stability of the Ag-CoFe2O4/rGO nanocomposite as compared to the other samples.

Escherichia coli is a harmful Gram-negative bacterium commonly found in the gut of warm-blooded organisms and affects millions of people annually worldwide. In this study, we have synthesized a ZnO-CuO nanocomposite (NC) by a co-precipitation method and characterized the as-synthesized NC using FTIR spectroscopy, XRD, Raman spectroscopy, and FESEM techniques. To fabricate the immunosensor, the ZnO-CuO NC composite was screen-printed on gold-plated electrodes followed by physisorption of the anti-LPS E. coli antibody. The biosensor was optimized for higher specificity and sensitivity. The immunosensor exhibited a high sensitivity (11.04 μA CFU mL-1) with a low detection limit of 2 CFU mL-1 with a redox couple. The improved performance of the immunosensor is attributed to the synergistic effect of the NC and the antilipopolysaccharide antibody against E. coli. The selectivity studies were also carried out with Staphylococcus aureus to assess the specificity of the immunosensor. Testing in milk samples was done by spiking the milk samples with different concentrations of E. coli to check the potential of this immunosensor. We further checked the affinity between ZnO-CuO NC with E. coli LPS and the anti-LPS antibody using molecular docking studies. Atomic charge computation and interaction analyses were performed to support our hypothesis. Our results discern that there is a strong correlation between molecular docking studies and electrochemical characterization. The interaction analysis further displays the strong affinity between the antibody-LPS complex when immobilized with a nanoparticle composite (ZnO-CuO).

A novel greener methodology is reported for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) using gum Arabic (Acacia senegal) and the characterization of the ensuing TiO2 NPs by various techniques such as X-ray diffraction (XRD), Fourier transform infrared, Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray, transmission electron microscopy (TEM), high resolution-TEM, and UV-visible spectroscopy. The XRD analysis confirmed the formation of TiO2 NPs in the anatase phase with high crystal purity, while TEM confirmed the size to be 8.9 ± 1.5 nm with a spherical morphology. The electrode for the electrochemical detection of Pb2+ ions was modified by a carbon paste fabricated using the synthesized TiO2 NPs. Compared to the bare electrode, the fabricated electrode exhibited improved electro-catalytic activity toward the reduction of Pb2+ ions. The detection limit, quantification limit, and the sensitivity of the developed electrode were observed by using differential pulse voltammetry to be 506 ppb, 1.68 ppm, and 0.52 ± 0.01 μA μM-1, respectively. The constructed electrode was tested for the detection of lead content in plastic toys.

Efficiency of water oxidation catalysts in terms of overpotential, current density, and voltage stability over time with facile methods of their fabrication remains a key challenge in developing competent mechanisms of storing energy in the form of green hydrogen fuels. In this work, a rapid one-step aerosol-assisted chemical vapor deposition (AACVD) method is employed to synthesize amorphous and highly active cobalt-vanadium mixed oxide catalysts (CoVOx) directly over fluorine-doped tin oxide (FTO) substrates. Morphological and structural characterizations made by field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy techniques revealed the formation of pure-phase amorphous films with a gradual variation of topography as a function of deposition time. Of these films, the most active film (CoVOx-20) was obtained in 20 min deposition, showing a spongy networking of interwoven nanofibers with a homogeneous distribution of 3-4 nm pores, achieving an overpotential of 308 mV at 10 mA/cm2 current density. A much higher current density of 175 mA/cm2 could be achieved just at 380 mV of overpotential with Tafel slope as low as 62 mV/dec for this whole range while exhibiting long-term stability. Mass activity, electrochemical impedance spectroscopy data, and the estimation of electrochemically active surface area all endorsed this high catalytic performance of CoVOx-20, which is unprecedented for a low-cost, upscalable, and relatively less conductive substrate such as FTO used here. Our findings, thus, not only highlight the benefits of using AACVD in preparing two-dimensional amorphous catalysts but also prove the high efficiency of CoVOx materials thus obtained, as outlined in a plausible reaction mechanism.

Carbon quantum dots (CQDs), a novel fluorescent nanomaterial, have been extensively employed/explored in various applications, that is, biosensors, bioimaging, nanomedicine, therapeutics, photocatalysis, electrocatalysis, energy storage system, and so forth. In this study, we report the synthesis, characterization, and the application of phosphorus-doped CQDs (PCQDs), synthesized using trisodium citrate and phosphoric acid by the hydrothermal method. The effect of phosphorus doping on optical features and the formation of PCQDs have been explored elaborately by controlling the concentrations of precursors, reaction time, and the temperature. The fluorescent quantum yield for PCQDs was determined to be 16.1% at an excitation/emission wavelength of 310/440 nm. Also, the optical and structural properties of PCQDs were determined by using various spectroscopic and microscopic techniques. Static quenching of fluorescence was determined upon the addition of Fe3+ to PCQDs because of the formation of the fluorescent inactive complex (PCQDs-Fe3+). Hence, this chemistry leads to the development of a new fluorometric assay for the detection of Fe3+. The lower limit of Fe3+ detection is determined to be 9.5 nM (3σ/slope), with the linear fit from 20 nM to 3.0 μM (R 2 = 0.99). We have validated this new assay in the raw, ejected, and purified water samples of the RO plant by the standard addition method. These results suggest the possibility of developing a new commercial assay for Fe3+ detection in blood, urine, and various industrial waste and sewage water samples. Furthermore, recycling the pollutant water into the freshwater using filters that consist of PCQDs offers a great deal.

The microbiologically influenced corrosion (MIC) behavior of carbon steel is investigated in the presence of Vibrio and Pseudomonas. Sterilized natural seawater inoculated with Pseudomonas, Vibrio, and the mixture of Pseudomonas and Vibrio, separately, and they are utilized as the media for corrosion characterizations, which are closer to the natural environment in seawater. Weight loss measurements, electrochemical techniques (the open-circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization curves), and surface analysis (scanning electron microscopy (SEM)) are performed to explore the synergistic effect of Pseudomonas and Vibrio on the corrosion behavior of carbon steel. As seen from the growth curves of bacteria, the growth and propagation of Pseudomonas and Vibrio are affected by their metabolic activities. Besides, the results obtained by SEM show that more severe pitting corrosion is observed on the coupons exposed to the sterilized natural seawater inoculated with the mixture of Pseudomonas and Vibrio. Further, the results from electrochemical measurements and weight loss measurements suggest that under the synergistic effect of Pseudomonas and Vibrio, the initial corrosion rate of carbon steel is inhibited, while the latter corrosion is enhanced.

Herein, we present a greener approach to achieve an ultrasensitive, selective, and viable sensor engineered by amino acids as a recognition layer for simultaneous electrochemical sensing of toxic heavy metals (HMs). Electrochemical techniques like electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and square-wave anodic stripping voltammetry (SWASV) were applied to demonstrate sensing capabilities of the designed analytical tool. The comparative results of different amino acids demonstrate alanine's superior performance with a well-resolved and enhanced current signal for target metal ions due to strong complexation of its functional moieties. The working conditions for alanine-modified GCE were optimized by investigating the effect of alanine concentration, different supporting electrolytes, pH values, accumulation potentials, and time. The limits of detection for Zn2+, Cd2+, Cu2+, and Hg2+ were found to be 8.92, 5.77, 3.01, and 5.89 pM, respectively. The alanine-modified electrode revealed absolute discrimination ability, stability, and ultrasensitivity toward metal ions even in the presence of multifold interfering species. Likewise, greener modifier-designed electrodes possessed remarkable electrocatalytic activity, cost affordability, reproducibility, and applicability for picomolar level detection of HM ions in real water sample matrixes. Theoretical calculations for the HM-amino acid interaction also support a significantly improved mediator role of the alanine modifier that is consistent with the experimental findings.

Here, we report the use of Li2Mn(SO4)2 as a potential energy storage material and describe its route of synthesis and structural characterization over one electrochemical cycle. Li2Mn(SO4)2 is synthesized by ball milling of MnSO4·H2O and Li2SO4·H2O and characterized using a suite of techniques, in particular, ex situ X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy on the Mn and S K-edges to investigate the electronic and local geometry around the absorbing atoms. The prepared Li2Mn(SO4)2 electrodes undergo electrochemical cycles to different potential points on the charge-discharge curve and are then extracted from the cells at these points for ex situ structural analysis. Analysis of X-ray absorption spectroscopy (both near and fine structure part of the data) data suggests that there are minimal changes to the oxidation state of Mn and S ions during charge-discharge cycles. However, X-ray photoelectron spectroscopy analysis suggests that there are changes in the oxidation state of Mn, which appears to be different from the conclusion drawn from X-ray absorption spectroscopy. This difference in results during cycling can thus be attributed to electrochemical reactions being dominant at the surface of the Li2Mn(SO4)2 particles rather than in the bulk.

In this work, CdS nanoparticles were grown on top of a hematite (α-Fe2O3) film as photoanodes for the photoelectrochemical water splitting. Such type of composition was chosen to enhance the electrical conductivity and photoactivity of traditionally used bare hematite nanostructures. The fabricated thin film was probed by various physicochemical, electrochemical, and optical techniques, revealing high crystallinity of the prepared nanocomposite and the presence of two distinct phases with different band gaps. Furthermore, photoassisted water splitting tests exhibit a noteworthy photocurrent of 0.6 mA/cm2 and a relatively low onset potential of 0.4 V (vs reversible hydrogen electrode) for the composite electrode. The high photocurrent generation ability was attributed to the synergistic interplay between conduction and valence band (VB) levels of CdS and α-Fe2O3, which was further interpreted by J-V curves. Finally, electrochemical impedance spectroscopy investigation of the obtained films suggests that the photogenerated holes could be transferred from the VB of α-Fe2O3 to the electrolyte more efficiently in the hybrid nanostructure.

Copper oxide nanoparticles (CuO Nps) were synthesized using Caesalpinia bonducella seed extract via a green synthetic pathway and were evaluated for electrocatalytic properties by carrying out electrochemical detection of riboflavin [vitamin B2 (VB2)]. The seeds of C. bonducella are known to have strong antioxidant properties arising due to the presence of various components, including citrulline, phytosterinin, β-carotene, and flavonoids, which serve as reducing, stabilizing, and capping agents. The synthesized CuO Nps were characterized using UV-visible spectroscopy, Fourier transform infrared spectroscopy, thermogravimetrc analysis-differential thermal analysis, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy and further used as a modifier for a graphite electrode surface. The modified electrode was electrochemically characterized by cyclic voltammetry, square-wave voltammetry, and chronoamperometry techniques and then assessed for electrocatalysis by carrying out the detection of VB2. The electrochemical sensor could be used for nanomolar detection of VB2 with an observed linear range of 3.13-56.3 nM with a limit of detection of 1.04 nM. The electrode showed good stability and reproducibility over a period of 120 days. The CuO Nps were further analyzed for antibacterial effect with Gram-positive and Gram-negative bacteria, and in both cases, high antibacterial activity was clearly observed. The newly synthesized nanoparticles, thus, proved to be an interesting material for electrochemical and biological studies.

DNA binding investigations are critical for designing better pharmaceutical compounds since the binding of a compound to dsDNA in the minor groove is critical in drug discovery. Although only one in vitro study on the DNA binding mode of apigenin (APG) has been conducted, there have been no electrochemical and theoretical studies reported. We hereby report the mechanism of binding interaction of APG and a new class of sulfonamide-modified flavonoids, apigenin disulfonamide (ADSAM) and apigenin trisulfonamide (ATSAM), with deoxyribonucleic acid (DNA). This study was conducted using multispectroscopic instrumentation techniques, which include UV-vis absorption, thermal denaturation, fluorescence, and Fourier transform infrared (FTIR) spectroscopy, and electrochemical and viscosity measurement methods. Also, molecular docking studies were conducted at room temperature under physiological conditions (pH 7.4). The molecular docking studies showed that, in all cases, the lowest energy docking poses bind to the minor groove of DNA and the apigenin-DNA complex was stabilized by several hydrogen bonds. Also, π-sulfur interactions played a role in the stabilization of the ADSAM-DNA and ATSAM-DNA complexes. The binding affinities of the lowest energy docking pose (schematic diagram of table of content (TOC)) of APG-DNA, ADSAM-DNA, and ATSAM-DNA complexes were found to be -8.2, -8.5, and -8.4 kcal mol-1, respectively. The electrochemical binding constants K b were determined to be (1.05 × 105) ± 0.04, (0.47 × 105) ± 0.02, and (8.13 × 105) ± 0.03 for APG, ADSAM, and ATSAM, respectively (all of the tests were run in triplicate and expressed as the mean and standard deviation (SD)). The K b constants calculated for APG, ADSAM, and ATSAM are in harmony for all techniques. As a result of the incorporation of dimethylsulfamate groups into the APG structure, in the ADSAM-dsDNA and ATSAM-dsDNA complexes, in addition to hydrogen bonds, π-sulfur interactions have also contributed to the stabilization of the ligand-DNA complexes. This work provides new insights that could lead to the development of prospective drugs and vaccines.

Humic acid (HA), a natural polymer and soil component, was explored as a photosensitizer in dye-sensitized solar cells (DSSCs). Photophysical and electrochemical properties show that HA covers a broad visible range of the electromagnetic spectrum and exhibits a quasi-reversible nature in cyclic voltammetry (CV). Because of its abundant functionalities, HA was able to bind onto the nano-titania surface and possessed good thermal stability. HA was employed as a sensitizer in DSSCs and characterized by various photovoltaic techniques such as I-V, incident-photo-to-current conversion efficiency (IPCE), electrochemical impedance spectroscopy (EIS), and Tafel polarization. The HA-based device shows a power conversion efficiency (PCE) of 1.4% under 1 sun illumination. The device performance was enhanced when a coadsorbent, chenodeoxycholic acid (CDCA), along with HA was used and displayed 2.4% PCE under 0.5 sun illumination. The DSSCs employing HA with CDCA showed excellent stability up to 1000 h. The reported efficiency of devices with HA is better than that of devices with all natural sensitizers reported so far.

A simple S-S (disulfide)-bridged dimeric Schiff base probe, L, has been designed, synthesized, and successfully characterized for the specific recognition of Al3+ and Fe2+ ions as fluorometric and colorimetric "turn-on" responses in a dimethylformamide (DMF)-H2O solvent mixture, respectively. The probe L and each metal ion bind through a 1:1 complex stoichiometry, and the plausible sensing mechanism is proposed based on the inhibition of the photoinduced electron transfer process (PET). The reversible chemosensor L showed high sensitivity toward Al3+ and Fe2+ ions, which was analyzed by fluorescence and UV-vis spectroscopy techniques up to nanomolar detection limits, 38.26 × 10-9 and 17.54 × 10-9 M, respectively. These experimental details were advocated by density functional theory (DFT) calculations. The practical utility of the chemosensor L was further demonstrated in electrochemical sensing, in vitro antimicrobial activity, molecular logic gate function, and quantification of the trace amount of Al3+ and Fe2+ ions in real water samples.