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Antibiotics are essential medications for human and animal health, as they are used to battle urinary infections and bacterial diseases. Therefore, the rapid determination of antibiotic drugs in biological samples is necessary to address the current clinical challenge. Here, we developed a heterojunction ternary composite of BiOCl/BiVO

A needle-shaped perovskite, barium stannate (BaSnO3), was synthesized via a co-precipitation technique for the simultaneous electrochemical determination of antibiotic drug nitrofurantoin (NFTO) and pericardial drug nifedipine (NFP). The spectroscopic and microscopic result confirms that as-prepared BaSnO3 particles formed with desired crystalline nature, functional group, pore size, pore diameter, and fine needle-like morphology. The simultaneous electrochemical detection of the two pharmaceutical compounds was examined via cyclic voltammetry (CV) and differential pulse voltammetry (DPV) technique using BaSnO3-modified glassy carbon electrode (BaSnO3/GCE) at a potential range from +0.4 to − 1.2 V. The discrete and simultaneous detection of NFTO and NFP at the BaSnO3 sensor exhibits higher catalytic activity in terms of cathodic current and cathodic potential compared to bare GCE. DPV results of the BaSnO3 sensor provide improved linear ranges and limits of detection for NFTO (0.01–42.65 µM; 42.65–557.65 μM, 0.062 μM, respectively) and NFP (0.01–697.65 μM, 0.0168 μM, respectively). Besides, the BaSnO3-fabricated sensor exhibits good sensitivity, reproducibility, and repeatability. The modified electrode shows excellent recoveries of NFTO (97.0–100.7%) and NFP (98.7–101.3%) in plasma, urine, and milk samples with an acceptable relative standard deviation (RSD) of 1.6–4.8%.

Herein, we fabricated a feasible and accurate sensing platform for the quantification of toxic organic pollutant 2-nitroaniline (2-NA) in water samples through electrocatalyst made up of bismuth molybdate (Bi2MoO6, BMO) functionalized carbon nanofiber (f-CNF) modified electrode. The preparation of BMO/f-CNF composite is of two methods, such as co-precipitation (C-BMO/f-CNF) and ultrasonication method (U-BMO/f-CNF). The physicochemical properties of the composites were characterized by XRD, FTIR, Raman, BET, FE-SEM, and HR-TEM techniques. At U-BMO/f-CNF, the charge transfer resistance was low (Rct = 12.47 Ω) compared to C-BMO/f-CNF because nanosized U-BMO particles correctly aim at the defective sites of the f-CNF surface wall. Further, the electrocatalytic activity of C&U-BMO/f-CNF composites was examined by cyclic voltammetry (CV) and differential pulse voltammetry techniques (DPV) for the electrochemical detection of 2-nitroaniline (2-NA). The U-BMO/f-CNF/GCE shows a higher cathodic current, wide dynamic linear range of 0.01–168.01 µM, and superior electrocatalytic activity with a low detection limit (0.0437 µM) and good sensitivity (0.6857 μA μM−1 cm−2). The excellent selectivity nature of U-BMO/f-CNF/GCE was observed in the presence of various organic pollutants and a few toxic metal cations. The practical applicability such as stability, repeatability towards 2-NA outcomes with accepted results. Besides, the practical viability of as proposed U-BMO/f-CNF sensor was investigated in soil and lake water samples delivers good recovery results. Hence from these analyses, we conclude that U-BMO/f-CNF/GCE potential for the determination of hazardous environmental pollutant 2-NA.

In recent years, advanced functional materials have been attaining a much important role in electrochemical sensors for day-to-day life activities. The specific detection of (bio) sensor with a cost-effective method has focused much recently and more comfortable with making a low-cost device for practical applications. Herein, we used a cost-effective method for fabricating the electrochemical sensing detector for promethazine hydrochloride (PHC) using cashew like cobalt tungstate (CW). The CW was synthesized using a simple co-precipitation method and was characterized using FTIR, Raman, XRD, FE-SEM, XPS, EDAX, and elemental mapping analysis. Also, the electrochemical activity and potential impact of the CW were scrutinized by CV and used towards the oxidation of PHC. As a result, the electrochemical experiments proved that the CW exhibits superior electrochemical performance with lower LOD and sensitivity of 0.0159 µM and 0.3056 µA µM−1 cm−2, respectively. Furthermore, the selectivity, repeatability, reproducibility, and real samples analysis of the sensor confirmed the promising nature of the CW modified electrode towards the detection of PHC.

The coordination of therapeutically interesting designed complexes of stoichiometry [ML(Met)Cl2] [where M = Cu(II), Co(II), Ni(II), Mn(II) and Zn(II), L = benzylidene-4-aminoantipyrine and Met = methionine] has been ascertained on the basis of physicochemical techniques. Their interaction with CT DNA reveals that they are good intercalators. The anticancer mechanism of our complexes is documented from their enhanced DNA splitting personalities under physiological conditions. To reveal the chemotherapeutic action of these complexes, we explored the inflammatory response, analgesic and antioxidant activities. Moreover, all the complexes show good antimicrobial activity against few bacterial and fungal strains. Our study has identified the mechanism of action of these complexes on inhibiting tumor cells and suggested that they have great potential as novel anticancer agents.

The DNA interaction efficacies of mixed-ligand complexes [ML(phen)2]Cl [L = a Schiff base derived from p-substituted benzaldehyde (L1 = NO2/L2 = –OCH3) and methionine; phen = 1,10-phenanthroline, the co-ligand] have been explored by absorption, electrochemistry, viscosity measurements, and agarose gel electrophoresis. The results indicate that these complexes can bind to calf thymus DNA via an intercalative mode and show efficient cleavage activity in the presence of H2O2. They are dose dependent. The antioxidative properties reveal that one complex has a stronger radical-scavenging potency than ligands. The complexes exhibit superoxide dismutase (SOD)-like activity with their IC 50 values ranging from 0.46 to 2.93 µM. Moreover, all the complexes have shown relatively high antibacterial and antifungal potencies. The in vitro chemosensitivity of the studied complexes exhibits significant cytotoxic effects, comparable to those reported for cisplatin. These findings represent a prompting to search for the probable interaction of these complexes with other cellular elements of fundamental consequence in cell proliferation.

Few new mixed ligand transition metal complexes of the stoichiometry [ML(A) 2 ], where M = Co(II), Ni(II), Cu(II) and Zn(II), L = FFAP (furfurylidene-4-aminoantipyrine) and A = amino acid (glycine/alanine/valine), have been designed, synthesized and characterized. The molar conductivity of the complexes in DMF at 10 −3 M concentration shows that they are non-electrolytes. The interaction of these complexes with CT-DNA indicates that the valine mixed ligand complexes are having higher binding constant than alanine and glycine mixed ligand complexes. This analysis reveals that binding constant depends on the size of the alkyl group present in the amino acid. The binding constants of valine mixed ligand complexes are in the order of 10 4 to 10 5 M −1 revealing that the complexes interact with DNA through moderate intercalation mode. The metal complexes exhibit effective cleavage of pUC19 DNA but it is not preceded via radical cleavage and superoxide anion radical. They are good antimicrobial agents than the free ligand. On comparing the IC 50 values, [Ni(L)(Gly) 2 ] is considered as a potential drug to eliminate the hydroxyl radical.

This work reports an effort to understand the role of amino acid with DNA interactions in binding of biologically imperative metallointercalators [Cu(II), Ni(II) and Zn(II)], incorporated by benzylidine-4-aminoantipyrine (L) and l -methionine (Met) ligands. Herein, the pre-clinical evaluations of synthesized amino acid mixed-ligand complexes, inflammatory response and analgesic activity, have been done. In vivo and in vitro anti-tumor functions of the complexes against Ehrlich ascites carcinoma tumor model have been investigated. All these metal chelates are strong SOD mimetic compounds and also behave as peroxyl radical scavengers. Towards non-cancerous cell line, Cu(II) complex exhibits very low toxicity. On the other hand all the complexes have been found to exhibit cytotoxic effects against cancerous cell lines with potency more than that of the widely used drug cisplatin and hence they have the potential to act as promising anticancer agents. Captivatingly, they are non-toxic to normal cell lymphocytes, revealing that they are selective in killing only the cancer cells.

Three novel mixed-ligand complexes using pyrazolone derivative (4-chloro-benzylidene-4-aminoantipyrine) as primary ligand and l -methionine as co-ligand, were synthesized and characterized by physico-chemical analytical techniques. The DNA interaction of these complexes was investigated by electronic absorption spectroscopy, viscosity, cyclic voltammetry and gel electrophoresis measurements. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens.

Transition metals have an important place within medicinal inorganic chemistry. Transition metals exhibit different oxidation states and can interact with a number of negatively charged molecules. This activity of transition metals led to the recent development of drugs which are based on metals and are considered to be potential candidates for pharmacological and therapeutic applications. This review focuses on research undertaken over the past few decades which has sought to possess preclinical pharmacological screenings like anti-microbial, anti-inflammatory and anti-tumor action of synthetic transition metal complexes. It concentrates primarily on a limited number of first row transition metal complexes particularly V(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes and traces the pharmacological applications of these coordination compounds. In the first part, the nitrogen, oxygen and sulfur donor ligands chelating to transition metals used in metallodrugs are described. The second part describes the pre-clinical screenings viz., anti-microbial, anti-inflammatory and anti-tumor responses of the above coordination compounds incorporating these nitrogen, oxygen and sulfur donor ligands. This survey encourages further research in this field for future applications.

A new family of tryptophan based mixed-ligand complexes has been synthesized and characterized. DNA (Calf thymus) binding properties of the complexes have been explored by UV–vis, viscosity measurements and cyclic voltammetry. All the experimental evidence suggest that the ancillary ligand 2,2′-bipyridine influences the intercalative binding of these complexes to CT DNA. The DNA cleavage efficiencies of these complexes with pBR322 DNA were investigated by gel electrophoresis. The complexes were found to promote the cleavage of pBR322 DNA from the supercoiled form I to the open circular form II in the presence of an oxidizing agent (H2O2). Microbial property of these complexes as antibacterial agents has been investigated against Gram-negative and Gram-positive bacteria.

Mixed-ligand Cu(II), Ni(II), Co(II), and Zn(II) complexes using a tryptophan-derived Schiff base (obtained by the condensation of tryptophan and benzaldehyde) as the primary ligand and 1,10-phenanthroline as the co-ligand were synthesized and characterized analytically and spectroscopically by performing elemental analyses, magnetic susceptibility and molar conductance measurements, UV-Vis, IR, NMR, and FAB-MS. The binding properties of metal complexes with DNA were investigated by electronic absorption spectroscopy, cyclic voltammetry, and by performing viscosity measurements, and the results showed that these complexes have the ability to interact with DNA via an intercalative mode. The DNA cleavage efficiencies of these complexes with pUC19 DNA were investigated by gel electrophoresis. The complexes were found to promote the cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and the linear form III in the presence of ascorbic acid. Finally, the in vitro antibacterial activities of the Schiff base and its mixed-ligand metal complexes were screened against the bacteria Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhi. The antibacterial screening data revealed that the complexes show growth inhibitory activity against bacteria.

A new series of cysteine-based metal(II) complexes with 2,2'-bipyridine or 1,10-phenanthroline as co-ligand have been prepared and characterized. Their DNA binding and cleavage properties have been studied. The analytical and spectroscopic data of complexes 1-18 reveal that the complexes adopt an octahedral geometry around the central metal ion in which the cysteine is coordinated through NS and NN atoms, respectively. Spectroscopic titration and viscosity measurements reveal that the complexes bind to DNA through an intercalative mode. Electrophoresis measurements exhibit that they cleave pBR322 DNA efficiently in the presence of 3-mercaptopropionic acid (MPA), probably via hydrolytic mechanism with the involvement of (•)OH. The in vitro anticancer activities indicate that the Cu(II) complexes are active against four selected human tumor cell lines. Furthermore, it is remarkable that all the complexes exhibit significant photocytotoxicity against human breast cancer cell lines (MCF-7) with a potency more than the widely used drugs photofrin and cisplatin indicating that they have the potential to act as effective anticancer drugs in a dose-dependent manner.

Pyrazolone incorporating N-acetylcysteine (NAC) mixed-ligand complexes are described as promising anti-inflammatory, anticonvulsant, SODs mimetic and cytotoxic compounds possibly due to its antioxidant profile. In this study, we have evaluated the pharmacologic activity, antioxidant and toxicological profiles of compounds ( 1 – 6 ). Among them, compounds 1 and 4 were haemobiocompatible than the others. Both complexes 1 and 4 display efficient photo-nuclease activity upon irradiation with UV-A light of 365 nm and red light of 647 nm as compared with others. Mechanistic studies reveal that the DNA cleavage oxidative pathway involves H 2 O 2 and singlet oxygen as the reactive oxygen species. Interestingly, both compounds 1 and 4 , show non-toxic effects in vitro to human normal lymphocyte cells, revealing that they are selective in killing only the cancer cells as expected for a better drug. In addition, considering the safety profile, these compounds are promising as preventive and/or therapeutic agents against oxidative damage.

The 4-aminoantipyrine derivatives ( NO 2 , OCH 3 ) and their mixed-ligand complexes with amino acids have been synthesized and investigated for their binding with CT DNA using UV–visible spectroscopy, cyclic voltammetry, and viscosity measurements under physiological conditions of pH (stomach 4.7; blood 7.4). The results from all techniques i.e. binding constant ( K b ), and free energy change (Δ G ) were in good agreement and inferred spontaneous compound–DNA complexes formation via intercalation. Among all the compounds 1 and 4 showed comparatively greater binding at pH 7.4 as evident from its greater K b values. All the complexes exhibit oxidative cleavage of supercoiled (SC) pBR322 plasmid DNA in the presence of H 2 O 2 as an activator. It is remarkable that at 25 μM concentration 1 and 4 completely degrade SC DNA into undetectable minor fragments and thus they act as efficient chemical nucleases. Among the new complexes, complexes 1 and 4 have highest potential against all the microorganisms tested. The results of the above biological experiments also reveal that the choice of different metal ions has little influence on the DNA binding, DNA cleavage and antimicrobial assay.

Few transition metal complexes of tetradentate N(2)O(2) donor Schiff base ligands containing 2-hydroxybenzylidene-4-aminoantipyrine and amino acids (alanine/valine) abbreviated to KHL(1)/KHL(2) have been synthesized. All the metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The Schiff bases KHL(1)/KHL(2) are found to act as tetradentate ligands using N(2)O(2) donor set of atoms leading to a square-planar geometry for the complexes around the metal ions. The binding behaviors of the complexes to calf thymus DNA have been investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through minor groove binding mode. The studies on mechanism of photocleavage reveal that singlet oxygen ((1)O(2)) and superoxide anion radical (O(2)(-)) may play an important role in the photocleavage. The Schiff bases and their metal complexes have been screened for their in vitro antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae and antifungal activities against Aspergillus niger, Fusarium solani, Culvularia lunata, Rhizoctonia bataicola and Candida albicans by MIC method.