Azulene-based materials present very appealing properties for the preparation of advanced materials. They can be irreversibly electrooxidated, leading to polymers, which can be deposited on electrodes and modified. This paper shows several experiments concerning the preparation of modified electrodes based on (E)-5-(azulen-1-yldiazenyl)-1H-tetrazole (L). L has a tetrazole complexing unit, which can be attached to the electrode’s surface and recognized. L has been deeply characterized by electrochemical techniques. Complexing modified electrodes have been prepared and tested in different conditions. Functional modified electrodes based on L obtained by controlled potential electrolysis were examined by AFM and SEM to see the influences of charge and potential on the deposited polyz films’ morphologies. The modified electrodes prepared in different conditions have been tested for heavy metal ion sensing. The new azulene-based modified electrode demonstrated its feasibility for Pb ions analysis (detection limit of 5 × 10−8 M, and linear domain between 5 × 10−8 M and 10−6 M) and potential use in future applications for real water samples analysis.

Chemically modified electrodes (CMEs) based on polymeric films of E-5-((5-isopropyl-3,8-dimethylazulen-1-yl) diazenyl)-1H-tetrazole (L) deposited on the surface of the glassy carbon electrode have been used for the recognition of heavy metal (Me) ions. The electrochemical study of L was done by three methods: differential pulse voltammetry (DPV), cyclic voltammetry (CV), and rotating disk electrode voltammetry (RDE). The CV, DPV, and RDE studies for L were performed at different concentrations in 0.1 M tetrabutylammonium perchlorate solutions in acetonitrile. The polymeric films were formed by successive cycling or by controlled potential electrolysis (CPE). The film formation was proven by recording the CV curves of the CMEs in ferrocene solution. The CMEs prepared at different charges or potentials were used for detection of heavy metal ions. Synthetic samples of heavy metal ions (Cd(II), Pb(II), Cu(II), Hg(II)) of concentrations between 10−8 and 10−4 M were analyzed. The most intense signal was obtained for Pb(II) ion (detection limit of about 10−8 M). Pb(II) ion can be detected by these CMEs in waters at such concentrations. The ability of the ligand L to form complexes with Pb(II) and Hg(II) ions was also tested by UV-Vis spectrometry. The obtained results showed the formation of Me(II)L2 complexes.

Preventing and controlling the spread of multidrug-resistant (MDR) bacteria implicated in healthcare-associated infections is the greatest challenge of the health systems. In recent decades, research has shown the need for passive antibacterial protection of surfaces in order to reduce the microbial load and microbial biofilm development, frequently associated with transmission of infections. The aim of the present study is to analyze the efficiency of photocatalytic antimicrobial protection methods of surfaces using the new photocatalytic paint activated by light in the visible spectrum. The new composition is characterized by a wide range of analytical methods, such as UV-VIS spectroscopy, electron microscopy (SEM), X-ray powder diffraction (PXRD) or X-ray photoelectron spectroscopy (XPS). The photocatalytic activity in the UV-A was compared with the one in the visible light spectrum using an internal method developed on the basis of DIN 52980: 2008-10 standard and ISO 10678—2010 standard. Migration of metal ions in the composition was tested based on SR EN1186-3: 2003 standard. The new photocatalytic antimicrobial method uses a type of photocatalytic paint that is active in the visible spectral range and generates reactive oxygen species with inhibitory effect against all tested microbial strains.

Our work presents, for the first time, a comprehensive study of the synthesis of fully metallic platinum nanoparticles (Pt-NPs) involving the ablation process in double distilled water using a KrF excimer laser. To obtain detailed information on Pt-NP morphology and optical properties, prepared colloids were characterized using High Resolution Scanning Transmission Electron Microscopy (HR-STEM) with advanced capabilities for Energy Dispersive X-ray Analysis (EDX), UV/Vis optical spectroscopy, and Direct Analysis in Real Time—Mass Spectrometry (DART-MS). The influence of the applied laser fluence and laser repetition rate (RR) values on the characteristics of the obtained Pt-NPs and the ablation process, respectively, were also analyzed. Spherical and spherical-like nanoparticles exhibiting aggregation were produced. The Pt-NP mean size values were between 2.2 ± 1.2 nm and 4.0 ± 1.0 nm, while their interplanar distance measurements showed a face-centered cubic (FFC) Pt lattice (111), as revealed by HR–STEM measurements, for all investigated samples. The smallest mean size of 2.2 nm of the Pt-NPs was obtained using a 2.3 J cm−2 laser fluence at a 10 Hz RR, and the narrowest size distribution of the NPs was obtained with a 2.3 J cm−2 laser fluence at a 40 Hz RR. A linear dependence of the Pt-NP diameters versus the laser repetition rate was found at a constant fluence of 2.3 J cm−2. The proposed eco-friendly synthesis route of Pt-NPs, because of its relative simplicity, has the potential for use in industrial production.

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