Search

Bismuth based hybrid perovskites light absorbers are good candidates for developing lead-free and air-stable photovoltaics, but they have historically been constrained by poor surface morphologies and large band-gap energies.

Oxidized/reduced carbon dots (CDs) with tunable optical features have emerged as a new class of CDs having a common "molecular origin" but different fluorescence (FL) behaviors. In the present work, using "banana peel" as a sole carbon source followed by doping with fluorine (F), boron (B), and nitrogen (N) over CDs, banana peel-derived carbon dots (BP-CDs) were synthesized using a well-known hydrothermal synthesis method. Moreover, as-synthesized BP-CDs were further reduced to "rBP-CDs" by NaBH

Co-exfoliated GNP/MoS2 was synthesized in one step and used for supercapacitor study.

The redox non-innocent behaviour of non-chelated μ-bis-η1-N,η1-N BTD (2,1,3-benzothiadiazole)-bridged mixed valent diruthenium and triruthenium complexes is attributed to a moderately coupled delocalised electronic state with Vab ≈ 2640–2890 cm−1.

The one-pot synthesis of Fe doped carbon dots (Fe-N@CDs) and its composite with Fe3O4 nanoparticles (Fe3O4-CDs) for detection and degradation of doxycycline.

Waste upcycling to valuable chemicals has gained significant attention in recent years as a way to reduce waste and promote circular economy. The transition to a circular economy that includes...

Recently, metal-organic frameworks (MOFs) have been widely employed as a sacrificial template for the construction of nanostructured materials for a range of applications including energy storage. Herein, we report a facile mixed-ligand strategy for the synthesis of a Cu-MOF, [Cu3(Azopy)3(BTTC)3(H2O)3·2H2O]n (where BTTC = 1,2,4,5-benzenetetracarboxylic acid and Azopy = 4,4'-azopyridine), via a slow-diffusion method at room temperature. X-ray analysis authenticates the two-dimensional (2D)-layered framework of Cu-MOF. Topologically, this 2D-layered structure is assigned as a 4-connected unimodal net with sql topology. Further, nanostructured CuO is obtained via a simple precipitation method by employing Cu-MOF as a precursor. After analysis of their physicochemical properties through various techniques, both materials are used as surface modifiers of glassy carbon electrodes for a comparative electrochemical study. The results reveal a superior charge storage performance of CuO (244.2 F g-1 at a current density of 0.8 A g-1) with a high rate capability compared to Cu-MOF. This observation paves the pathway for the strategic design of high-performing supercapacitor electrode materials.

Fluorene-chloroquine hybrids have been identified as a new promising class of antiplasmodial agents. The most active compound 9 d exhibited good in vitro antiplasmodial activity against a chloroquine-sensitive NF54 strain of the human malaria parasite Plasmodium falciparum with an IC

The increasing contamination of environmental media is a serious health issue requiring advanced methods to detect actual and emerging pollutants. In particular, high-sensitivity sensors for monitoring water pollutants are under deep investigation. Here, we review the synthesis, optical properties and applications of carbon dots for sensing contaminants in water samples. Fluorescence-based sensors have achieved ultrasensitive detection at nanomolar to picomolar concentrations. Carbon dot sensors have unique advantages such as biocompatibility, easy preparation, optical activity and wide applicability.

Thioether linked meso BODIPY DYEmer 3 was synthesized by two different routes. The reaction of dipyrrothioketone 1 and 8-chloro BODIPY 2 in the presence of triethylamine followed by complexation with BF[Formula: see text] resulted in thioether linked meso functionalized BODIPY DYEmer 3. Using another route, the reaction of 8-chloro BODIPY 2 with sodium hydrosulphide (NaSH) at room temperature resulted in the thioether linked meso BODIPY DYEmer 3. The DYEmer 3 was characterized by 1H, [Formula: see text]C, [Formula: see text]B, [Formula: see text]F NMR, HRMS, and single crystal X-ray crystallography. The properties of DYEmer 3 was compared with the previously reported thioether linked [Formula: see text] and [Formula: see text] BODIPY DYEmers 4 and 5. The structural parameters indicating the intramolecular arrangements of two BODIPY units of DYEmer were compared and corelated with the observed properties. The time-dependent DFT (TD-DFT) calculations suggested that the thioether group at meso position of BODIPY 3 stabilizes the LUMO energy than 8-chloro BODIPY 2. Compared to 8-chloro BODIPY 2 the HOMO-1 of DYEmer 3 is destabilized whereas the LUMO+1 is stabilized.

A new method of activating corrole macrocycles via an in situ generated SCN radical has been developed at very mild conditions at room temperature. This photoredox reaction resulted in the generation of tetrathiocyanatocorroles in good yields. The synthesis of tetrathiocyanatocorroles was never reported earlier. Single-crystal XRD analysis reveals that the insertion of four thiocyanate moieties at the four β-pyrrolic positions has imparted significant distortion to the corrole macrocycle. The generated tetrathiocyanatocorroles are different from the parent corroles in many ways. The photophysical properties of the newly synthesized tetrathiocyanatocorroles are dramatically altered from the parent corroles. The absorption feature of these modified corrole derivatives (both position and intensity) bears a nice similarity with the chlorophyll-a macrocycle. Thus, these newly synthesized molecules can be considered as spectroscopic model systems for chlorophyll-a pigments. The observed absorption and emission spectra of these tetrathiocyanatocorroles certainly point out that these newly developed ligand scaffolds and their various metal complexes will have immense potential as pigments in solar cells and also as NIR-emissive dyes. The observed C-H···Au weak interactions in a representative Au(III)-corrole complex point out that these complexes are capable of activating the unfunctionalized C-H groups and thus will have potential implications in C-H activation reactions.

Hydrogenases are versatile enzymatic catalysts with an unmet hydrogen evolution reactivity (HER) from synthetic bio-inspired systems. The binuclear active site only has one-site reactivity of the distal Fed atom. Here, binuclear complexes [Fe2(CO)5(μ-Mebdt)(P(4-C6H4OCH3)3)] 1 and [Fe2(CO)5(μ-Mebdt)(PPh2Py)] 2 are presented, which show electrocatalytic activity in the presence of weak acids as a proton source for the HER. Despite almost identical structural and spectroscopic properties (bond distances and angles from single-crystal X-ray; IR, UV/vis, and NMR), introduction of a nitrogen base atom in the phosphine ligand in 2 markedly changes site reactivity. The bridging benzenedithiolate ligand Mebdt interacts with the terminal ligand’s phenyl aromatic rings and stabilizes the reduced states of the catalysts. Although 1 with monodentate phosphine terminal ligands only shows a distal iron atom HER activity by a sequence of electrochemical and protonation steps, the lone pair of pyridine nitrogen in 2 acts as the primary site of protonation. This swaps the iron atom catalytic activity toward the proximal iron for complex 2. Density-functional theory (DFT) calculations reveal the role of terminal phosphines ligands without/with pendant amines by directing the proton transfer steps. The reactivity of 1 is a thiol-based protonation of a dangling bond in 1– and distal iron hydride mechanism, which may follow either an ECEC or EECC sequence, depending on the choice of acid. The pendant amine in 2 enables a terminal ligand protonation and an ECEC reactivity. The introduction of a terminal nitrogen atom enables the control of site reactivity in a binuclear system.

Because of a continuous increase in energy demands and environmental concerns, a focus has been on the design and construction of a highly efficient, low-cost, environmentally friendly, and noble-metal free electrocatalyst for energy technology. Herein we report facile synthesis of the mixed-valence trinuclear cobalt complex 1 by the reaction of 2-amino-1-phenylethanol and CoCl2·6H2O in methanol as the solvent at room temperature. Further, 1 was reduced by using aqueous N2H4 as a simple reducing agent, followed by calcination at 300 °C for 3 h, yielding a nitrogen-doped mixed phase cobalt [β-Co(OH)2 and CoO] nanocatalyst (N@MPCoNC). Both 1 and N@MPCoNC were characterized by various physicochemical techniques. Moreover, 1 was authenticated by single-crystal X-ray diffraction studies. The hybrid N@MPCoNC reveals a unique electronic and morphological structure, offering a low overpotential of 390 mV for a stable current density of 10 mA cm-2 with high durability. This N@MPCoNC showed excellent electrocatalytic as well as photocatalytic activity for oxygen evolution reaction compared to 1.

Organic materials possessing solid-state emission responsive to external stimuli have significance in a variety of material, biomedical, and optoelectronic applications. Organic molecules having different donor-acceptor architectures integrated with aggregation-induced emission (AIE) fluorophores have been utilized in development of mechanofluorochromic (MFC) materials. In this work, we have designed and synthesized phenanthroimidazole (PI) based derivatives TPE-PI-1, TPE-PI-2, TPE-PI-3, PTZ-PI-1, PTZ-PI-2, and PTZ-PI-3 where in donors tetraphenylethylene-TPE (D) and phenothiazine-PTZ (D') of contrasting donor abilities are attached to the N and C atom positions of PI. The position and mode of attachment of the donors have been changed, and an additional PTZ spacer has been introduced which has a direct consequence on their photophysical and electronic properties. The PI derivatives manifest AIE, solvatochromic, and mechanochromic behavior. The single crystal X-ray analysis of TPE-PI-1 and PTZ-PI-2 reveals bent structures for the PTZ unit and a twisted conformation for TPE moieties. The density functional theory calculations were used to obtain optimized ground-state structures of the PI derivatives. The work shows a comprehensive comparison of the photophysical, electronic, AIE, and MFC properties of the PI derivatives as an effect of variations in the position of donor, donor-acceptor strength, and change in molecular conformation on use of spacer.

Being cognizant of modern electronic devices, the scientists are continuing to investigate renewable green-energy resources for a decade. Amid different energy harvesting systems, the triboelectric nanogenerators (TENGs) have been found to be the most promising mechanical harvesting technology and have drawn attention to generate electrical energy. Thanks to its instant output power, choice to opt for wide-ranging materials, low maintenance cost, easy fabrication process and environmentally friendly nature. Due to numerous working modes of TENGs, it is dedicated to desired application at ambient conditions. In this review, an advance correlation of TENGs have been explained based on the variety of nanostructures, including 0D, 1D, 2D, 3D, metal organic frameworks (MOFs), coordination polymers (CPs), covalent organic frameworks (COFs), and perovskite materials. Moreover, an overview of previous and current perspectives of various nanomaterials, synthesis, fabrication and their applications in potential fields have been discussed in detail.

The recent trends and current state of perovskite solar cells (PSCs) suggested their potential for practical applications. Since their origin, organic-inorganic lead halide (MAPbX3) perovskite material-based PSCs have been widely attractive to the scientific community due to their simple manufacturing process, high performance, and cost effectiveness. In spite of the high performance, the lead halide perovskite solar cells are still agonizing due to the long-term stability and toxic nature of Pb. In the last 4 years or so, many alternative perovskite or perovskite-like materials were explored for the development of Pb-free PSCs. However, antimony (Sb)-based perovskite-like materials have shown enhanced stability and average photovoltaic performance. In this mini-review, we discuss the fabrication, recent trends, and current state of the Sb-based PSCs.

The development of a cost-effective and highly sensitive hydrogen peroxide sensor is of great importance. Electrochemical sensing is considered the most sensitive technique for hydrogen peroxide detection. Herein, we reported a cost-effective and highly sensitive hydrogen peroxide sensor using Co-doped δ-MnO2 (Co@δ-MnO2) flower-modified screen-printed carbon electrode. The δ-MnO2 and Co@δ-MnO2 flowers were synthesized by employing a hydrothermal approach. Advanced techniques such as PXRD, SEM, FTIR, Raman, UV, EDX, BET, and TEM were utilized to confirm the formation of δ-MnO2 and Co-doped δ-MnO2 flowers. The fabricated sensor exhibited an excellent detection limit (0.12 μM) and sensitivity of 5.3 μAμM−1 cm−2. Graphical abstract

In this study, we report the deposition of a thin layer of Cd(OH)₂ over δ-MnO₂ deposited on a fluorine-doped tin oxide (FTO) glass substrate, thereby forming a heterojunction with synergistic effects. Electrodes fabricated by a room-temperature, facile, and cost-effective chemical bath deposition method display enhanced photoactivity when used as cathodes for the hydrogen evolution reaction (HER) in a photoelectrochemical cell, with an observed photocurrent of 0.3 mA/cm² at 0 V vs reversible hydrogen electrode (RHE). The electrodes also showcase a dark electrocatalytic current of 2.9 mA/cm² without illumination. The δ-MnO₂/Cd(OH)₂ nano-heterostructure is analyzed thoroughly via various physicochemical, optical and electrochemical methods to understand the phenomena involved in the conduction characteristics. The enhanced photoconductivity is attributed to effective charge separation and transport by the presence of synergistic materials with optimal band gap energies. These results show promise for the use of birnessite-based materials as sustainable electro- or photocatalysts for the hydrogen evolution reaction.

MCM-41-supported ZnO-Cu(OH)Cl nanoparticles were synthesized via an incipient wetness impregnation technique using zinc chloride and copper chloride salts as well as water at room temperature. The catalyst was characterized by powder X-ray diffraction (PXRD), infrared spectroscopy (IR), and TGA, whereas surface and morphological studies were performed by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The above studies revealed the incorporation of metal species into the pores of MCM-41, leading to a decrease in surface area of the nanoparticles that was found to be 239.079 m2 /g. The substituents attached to the ketone determine the rate of the reaction, and the utilization of the green solvent 'water' astonishingly completes the hydrogenation reaction in 45 minutes at 40 °C with 100% conversion and 100% selectivity as analyzed by gas chromatography-mass spectrometry. Hence, ZnO-Cu(OH)Cl/MCM-41 nanoparticles with 2.46 wt% zinc and 6.39 wt% copper were demonstrated as an active catalyst for the reduction of ketones without using any gaseous hydrogen source making it highly efficient as well as environmentally and economically benign.

To get an idea about the most probable microporous supramolecular environment in the gel state, gelator molecule 1 has been crystallized from its gelling solvent (dimethylformamide). Crystal structure analysis of 1 shows a strong π···π stacking interaction between the electron-deficient pentafluorophenyl ring and electron-rich naphthyl ring. The gelling solvent situated in the "molecular pocket" stitches the gelators through weak H-bonding interactions to facilitate the formation of an organogel. Scanning electron microscopy analysis exhibits a ribbonlike fibrous morphology that resembles the supramolecular arrangement of 1 in its crystalline state, as evidenced by powder X-ray diffraction. In the presence of external stimuli (tetrabutylammonium fluoride), the organogel of 1 disassembles into sol. This sol-gel transformation phenomenon has been explained on the basis of X-ray single-crystal analysis. Single crystals obtained from the sol state show that naphthylic -OH of 1 gets deprotonated, resulting in C-C bond rotation that plays a major role in the sol-gel transformation. Gelator 1 exhibits weak green fluorescence in the gel state, whereas it shows highly intense yellow fluorescence in the sol state. Furthermore, a reversible sol-gel transformation associated with changes in the spectroscopic properties has been observed in the presence of acids and fluoride ions, respectively.

A new Na/Co-based heterometallic metal-organic framework, [Na2Co(SDCA)(μ2-OH)2(μ2-H2O)2(Azopy)]n (where Azopy = 4,4'-Azopyridine and SDCA = 2,5'-thiophenedicarboxylic acid) (1) with nanorod-shaped morphology was synthesized using mixed-ligand approach via slow-diffusion technique under ambient conditions. The crystal structure study demonstrates the proportion of Co(II) and Na(I) metal node to be 1:2 and the acquired coordination network reveals as a 3D architecture. Topologically, the 4-c Na(I) ion directs in situ assembly of 4-c SDCA linker and 6-c Co(II) ion, resulting in the formation of 4,4,6-c net with a topology named as smm3. Additionally, 1 was incorporated as a binder-free material for a glassy carbon electrode (1-GCE) to explore its supercapacitor performance, which reveals a high specific capacitance of 321.8 F g-1 at 4 A g-1 and notable rate performance (∼78.9% of initial capacitance up to 16 A g-1) as well as excellent cycling stability (retains 97.4% after 5000 cycles). The demonstrated strategy of employing different heterometallic clusters with mixed ligands markedly increases MOF's complexity and induces synergistic properties, which is highly favorable for electrochemical applications. Hence, the present approach can be extended to build a wide range of MOFs and synergistically enhanced electrochemical performance can be achieved.

Organic–inorganic nanohybrids are widely used as electrode materials for various applications due to their high conductivity with porosity and tuneable nanostructures. However, the poor stability of organic–inorganic hybrid materials in aqueous alkaline electrolytes and the presence of binders restrict their use in various electrochemical applications such as energy storage and electrocatalytic water splitting. A class of electrodeposited binder-free organic–inorganic hybrid materials based on a benzo[2,1,3]selenadiazole-5-carbonyl N-capped dipeptide (BSeLW) and metal hydroxide (Ni(OH)2) are prepared for electrochemical applications. The binder-free electrodeposited nanohybrids grown on carbon paper (CP) ((1 : 20) BSeLW/Ni(OH)2/CP) are stable in aqueous 1 M KOH electrolyte solution and exhibit pseudo-capacitive behavior with a high charge storage efficiency of 742 F g−1 at 1.5 A g−1. A prominent 71% specific capacitance retention at 10 A g−1 after 1000 cycles indicates higher stability of dipeptide-based organic–inorganic nanohybrids on the carbon paper-based electrode surface. Additionally, the nanohybrid shows catalytic activity for electrocatalytic water splitting with a low overpotential for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline aqueous 1 M KOH solution. This work elucidates the rational engineering of organic–inorganic binder-free multi-functional nanohybrid electrodes as a favorable candidate for high-performance energy storage and electrocatalyst for electrocatalytic water splitting.

Metal–organic frameworks (MOFs) are porous crystalline materials in which multidentate organic ligands and transition metal cations are linked via coordination bonds. The porosity of MOFs enables them to be used as drug carriers. Moreover, the presence of multiple coordination bonds makes them a desirable candidate for sustainable release of drugs which is a prerequisite for the treatment of many chronic and virulent intracellular infections by bacteria. These properties of MOFs have been extensively studied and utilized in various antibacterial studies where MOFs were used as antibacterial drug carriers or they themselves showed antibacterial activity or in composite form with many other available antimicrobial nanomaterials. This review focuses on the recent advances in MOFs and MOF composites for antibacterial drug delivery in various biological systems.

Mixed-metal metal-organic frameworks (M-MOFs) consist of at least two different metal ions as nodes in the same framework. The incorporation of a second or more metal ions provides structural/compositional diversity, multi-functionality and stability to the framework. Moreover, the periodical array of different metal ions in the framework may alter the physical/chemical properties of M-MOFs and result in fascinating applications. M-MOFs with exciting structural features offer superior supercapacitor performances compared to single metal MOFs due to the synergic effect of different metal ions. In this review, we summarize several synthetic methods to construct M-MOFs by employing various organic ligands or metalloligands. Further, we discuss the electrochemical performance of several M-MOFs and their derived composite materials for supercapacitor applications.

Mechanochromic emitters with an appropriate combination of properties for white hyperfluorescent solution-processable organic light emitting diodes (OLEDs) were developed involving phenothiazine, tetraphenylethylene, and electron withdrawing (cyano (–CN)) or phenyl acrylonitrile (–CHC(CN)Ph) groups. Among the four studied compounds, the best performance in white hyperfluorescent OLEDs was shown by one compound (named PTZTPE-3) due to its orange emission with a high photoluminescence quantum yield of 66% observed for toluene solution and of 39% for doped films, low-dispersity hole-transporting properties, appropriate ionization potential (5.5 eV) and electron affinity (3.24 eV). The perfect combination of these characteristics is required for efficient white hyperfluorescence. Mechanoluminescence properties with hypsochromically shifted emission under external stimuli were additionally detected and studied in detail for the developed PTZTPE compounds discovering their multifunctionality for either sensing, imaging, security, memory or other proposes. Using PTZTPE compounds hyperfluorescence systems were developed and utilized in simple processed white organic light-emitting diodes involving a conventional host, a host with thermally activated delayed fluorescence (TADF) properties and singlet emitters. Due to Forster resonance energy transfer from co-hosts to blue and orange emitters, hyperfluorescence based white OLEDs were developed. They were characterized by high quality of white electroluminescence with a color rendering index of 67 and CIE1931 color coordinates of (0.28, 0.38), in the best case. The maximum external quantum efficiency (8.2%) of the solution-processed OLED was higher than the theoretical limit (5–7.5%) of the devices based on conventional fluorescent emitters.

Cocrystallization of the geometrically demanding triptycene (TripH) with the compact and electron-rich ferrocene (FcH) and its derivatives afforded C–H---πCp assembled supramolecular chains of alternating (C5H5)(C5H4R)Fe and TripH molecules in a series of binary crystals: FcH/TripH (1), (C10H9)FeCHO/TripH (2), diferrocenyldiacetylene/TripH (3), paracyclophane-CC–Fc/TripH (4), and (C10H9)2Fe2/TripH (5). Analysis of the structure of cocrystals 1–5 (single crystal XRD) showed significant Hbridgehead---πCp interaction along with C–H---π and π---π interactions. Upon varying the groups on FcH, the appreciable Hbridgehead---πCp interaction remains in action to maintain the efficient packing and dense arrangement in the form of properly crystallized chains among the TripH and FcH derivatives mostly. In the case of 5, the effective close packing of such chain oligomers could not be achieved, so at this point, we reached a borderline at the structural landscape of TripH. This borderline can be described as an intermediate area between the native TripH and co-crystals domains, where TripH and Fc2 molecules form 2D ribbons, which are packed closely by T-shaped C–H---πPh interactions between TripH molecules which exactly reproduce the geometry of TripH---TripH interaction in the TripH native crystal.

Herein, we have reported a novel composite of nitrogen doped reduced graphene oxide (N-rGO) and strontium zirconate (SrZrO3). This new composite (N-rGO/SrZrO3) was synthesized using the reflux method. The physicochemical properties of N-rGO/SrZrO3 were determined using different advanced techniques such XRD, FE-SEM, EDX, FTIR and BET. Furthermore, a glassy carbon electrode was modified with N-rGO/SrZrO3 (GCE-2). This modified electrode was employed for the sensing of HQ. The electrochemically active surface area (ECSA) of this modified electrode (GCE-2) was calculated by employing the Randles–Sevcik equation. Furthermore, GCE-2 exhibited a good detection limit (0.61 μM) including high selectivity towards HQ.

The development of solid-state stimuli responsive materials has escalated following their intriguing colour switching properties and versatile material and optoelectronic applications. In this article, we have designed and synthesized donor–acceptor (D–A) isomers, namely p-PTZ, m-PTZ and o-PTZ, by functionalizing the para, meta and ortho positions of the benzothiazole (BT) ring with the phenothiazine (PTZ) moiety. The Suzuki cross-coupling reaction of the mono boronate ester of phenothiazine PTZ with the corresponding bromo derivatives of phenyl BT generated the isomers p-PTZ, m-PTZ and o-PTZ. The attachment of donor PTZ at different positions of the acceptor phenyl BT could exert influence on the donor–acceptor character and the molecular packing modes in the isomers, resulting in discrete photophysical and electronic properties. The isomers manifest contrasting emission properties in different solvents as a consequence of the twisted intramolecular charge transfer (TICT) state. The non-planar twisted structures of the isomers bring about aggregation induced emission (AIE) characteristics and reversible mechanofluorochromism (MFC) behaviour. The isomers display self-reversible colour switching by virtue of the different accessible conformers of the PTZ moiety. The p-PTZ isomer occurs as polymorphs owing to the conformational flexibility of the PTZ moiety. The structural and morphological differences in the polymorphs of p-PTZ were studied in detail using single crystal X-ray analysis, scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD) studies. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations were used to explore the electronic properties of the isomers in the ground and excited state. The isomers were capable of sensing trifluoroacetic acid in solution. A detailed comparison of the photophysical, electronic and structural properties of p-PTZ, m-PTZ and o-PTZ has been done with a view to studying the outcome of the positional change. The adopted design opens up different possibilities for study of novel stimuli responsive materials.

Herein, we report novel CaTiO3 pyramids, prepared by a hydrothermal approach using calcium nitrate and titanium butoxide in the presence of sodium hydroxide. The physio-chemical properties of the synthesized CaTiO3 pyramids were probed by PXRD, FTIR, BET, SEM and EDX. The synthesized CaTiO3 pyramids possess a good specific surface area which is beneficial for electrochemical applications. Thus, the CaTiO3 pyramids were applied as an electrode modifier to develop an electrochemical sensor. The working surface area of the glassy carbon (GC) electrode was fabricated with CaTiO3 pyramids using the drop casting method. This fabricated electrode was employed to determine urea using the cyclic voltammetry and I–V techniques. The fabricated electrode exhibited a good detection limit of 1.6 μM.

Though a large amount of literature has been reported on outlining the biological significance of zinc(II) Schiff base complexes, yet none of them have explored the influence of nuclearity on their properties. This report elaborates the targeted syntheses of two different hemi-salen ligands for their ability to produce Zn(II)-complexes with different nuclearity. Herein, one dimeric, [Zn2L12(N3)2] (1) and one trimeric [Zn3L22(N3)4] (2) [HL1 = (2-(((2-(diethylamino)ethyl)imino)methyl)phenol, HL2 = 2-(((3-(dimethylamino)-2,2-dimethylpropyl)imino)methyl)-6-methoxyphenol] complexes of hemi-salen ligands have been thoroughly screened for various biological studies including cytotoxic assay, DNA/protein-complex interplay, fluorescence imaging, and antibacterial pathogen tests. The trimer features the IC50 value of 9.651 ± 0.026 μM against the HeLa cancer cell line, one of the best figure by any Zn(II) hemi-salen complex to date. How the nuclearity dependency affects the supramolecular interactions is also a key point of interest in this study. The compounds exhibit strong DNA binding affinity and the dimer 1 predominantly binds to the minor grooves of DNA (binding energy = −5.8 kcal mol−1), whereas trimer 2 prefers the intercalative mode (binding energy = −7.1 kcal mol−1) in contrast to groove binding (binding energy = −6.2 kcal mol−1). The atypical phenomenon behind the conformational changes of biomolecules by these zinc complexes has been investigated through experimental procedures and further corroborated theoretically. Apart from this, it has been found that even at very low concentration (≤10 μM) of the ligand, HL1 and complexes can be effective for live cell imaging. It is worth mentioning that HL1 could be useful for the specific staining of the cell cytoplasm. Furthermore, the complexes have shown promising anti-bacterial activity; thus, they can be convenient for multiple biological applications.

Stimuli modulated photophysical properties of a new asymmetric multifunctional molecular probe, 2-(pyren-1-yl)-5-(pyridin-4-yl)thiazolo [5,4-d]thiazole (PYTZ-P) bearing electron-rich pyrene and electron-deficient pyridine units linked through a π-conjugated thiazolo [5,4-d]thiazole (TTz) bridge are reported. Its sensitivity towards protons (TFA) in solution is manifested in the form of bathochromically shifted emission that spreads all over the visible region, and is related to the increased acceptor strength of pyridine upon protonation and subsequent enhanced magnitude of intramolecular charge-transfer in the probe. Similar modulation of the luminescence behaviour of the probe was also observed in the solid state. These observations are well rationalised by the theoretical calculations. The applicability of the sensitivity of the probe towards TFA has been demonstrated by developing the ready-to-use portable paper strips. Furthermore, PYTZ-P showed different acid/base induced absorption/emission switching property. Interestingly, when the response of the probe was noted in the presence of several cations, modulation of the electronic properties was observed only in the presence of Hg

Despite being the most common component of numerous metalloenzymes in the human body, zinc complexes are still under-rated as chemotherapeutic agents. Herein, the present study opens up a key route toward enhanced chemotherapy with the help of two Zn