Modeling the spectral properties of poly(x-phenylenediamine) conducting polymers using a combined TD-DFT and electrostatic embedding approach

Synthesis, characterization and NLO properties of 1,4-phenylenediamine-based Schiff bases: a combined theoretical and experimental approach

In the current study, three novel 1,4-phenylenediamine-based chromophores (3a-3c) were synthesized and characterized and then their nonlinear optical (NLO) characteristics were explored theoretically. The characterization was done by spectroscopic analysis, i.e. FT-IR, UV-Visible, and NMR spectroscopy, and elemental analysis. Notably, these chromophores exhibited UV-Visible absorption within the range of 378.635-384.757 nm in acetonitrile solvent. Additionally, the FMO findings for 3a-3c revealed the narrowest band gap (4.129 eV) for 3c. The GRPs for these chromophores were derived from HOMO-LUMO energy values, which showed correspondence with FMO results by depicting a minimum hardness (2.065 eV) for 3c. Among these compounds, 3c displayed the highest nonlinear behavior with maximum μtot, βtot and γtot values of 4.79 D, 8.00 × 10-30 and 8.13 × 10-34 a.u., respectively. Our findings disclosed that the synthesized 1,4-phenylenediamine chromophores may be considered promising candidates for nonlinear optical materials, showing potential applications in the realm of optoelectronic devices.

Engineering boron and nitrogen codoped carbon nanoarchitectures to tailor molecularly imprinted polymers for PFOS determination

Per- and polyfluoroalkyl substances (PFAS) have gained significant attention as emerging contaminants due to their persistence, abundance, and adverse health effects. Consequently, the urgent need for ubiquitous and effective sensors capable of detecting and quantifying PFAS in complex environmental samples has become a priority. In this study, we present the development of an ultrasensitive molecularly imprinted polymer (MIP) electrochemical sensor tailored by chemically vapour-deposited boron and nitrogen codoped diamond-rich carbon nanoarchitectures for the selective determination of perfluorooctanesulfonic acid (PFOS). This approach allows for a multiscale reduction of MIP heterogeneities, leading to improved selectivity and sensitivity in PFOS detection. Interestingly, the peculiar carbon nanostructures induce a specific distribution of binding sites in the MIPs that exhibit a strong affinity for PFOS. The designed sensors demonstrated a low limit of detection (1.2 μg L^-1) and exhibited satisfactory selectivity and stability. To gain further insights into the molecular interactions between diamond-rich carbon surfaces, electropolymerised MIP, and the PFOS analyte, a set of density functional theory (DFT) calculations was performed. Validation of the sensor's performance was carried out by successfully determining PFOS concentrations in real complex samples, such as tap water and treated wastewater, with average recovery rates consistent with UHPLC-MS/MS results. These findings demonstrate the potential of MIP-supported diamond-rich carbon nanoarchitectures for water pollution monitoring, specifically targeting emerging contaminants. The proposed sensor design holds promise for the development of in situ PFOS monitoring devices operating under relevant environmental concentrations and conditions.