Carrageenan derived polyelectrolyte complexes material: An effective bifunctional for electrochemical sensing of sulfamethazine and antibacterial activity

Biopolymer-derived polyelectrolyte complexes (PECs) are a class of materials that have emerged as promising candidates for developing advanced electrochemical sensors due to their tunable properties, biocompatibility, cost-effective production, and high surface area. PECs are formed by combining positively and negatively charged polymers, resulting in a network with intriguing properties that can be tailored for specific sensing applications. The resultant PECs-based nanocomposites were used to modify the glassy carbon electrode (GCE) to detect the sulfamethazine (SFZ) antibiotic drug. In addition, electrochemical studies using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) are used to evaluate the SFZ detection ability. Similarly, various microscopic and spectroscopic studies investigated the nano composite's structural features and morphological behavior. The κ-CGN/P(Am-co-DMDAAc)-GO modified GCE demonstrated excellent detection ability of SFZ with the nano molar range and without interference with similar structural components. Furthermore, the newly fabricated electrode κ-CGN/P(Am-co-DMDAAc)-GO was derived from naturally available materials, water-soluble, low cost, biocompatible, exhibits good conductivity, and excellent catalytic properties. Finally, κ-CGN/P(Am-co-DMDAAc)-GO- modified GCE has versatile, practical applications for detecting SFZ in real-time samples and determining the efficacy of an antibacterial activity.

Effectively Reinforced α-Bi2O3 MPs/PDA-RGO Sensor for Selective Modality Sensing of a Hazardous Phenolic Compound

The phenolic compound trichlorophenol (TCP) is an ingredient in fungicides and herbicides. This compound's high stability, bioaccumulation, toxicity, and poor biodegradability result in severe environmental and biological health issues. Consequently, it is crucial to have an affordable and sensitive method for detecting TCP in environmental samples. In this study, α-phase bismuth oxide microplates and polydopamine-functionalized reduced graphene oxide (α-Bi2O3 MPs/PDA-RGO) were synthesized using a simple ultrasonic method and characterized with various analytical and physical characterizations. The conversion of the catechol moieties present in the resulting PDA-RGO material into quinones facilitates productive interactions with diverse functional groups, such as hydroxyl, amine, and imine. Consequently, the compounds 2,4,6-trichlorophenol (TCP) engages in electrochemical interactions with the aforementioned functional groups. As a result, TCP shows more excellent selectivity on the designed α-Bi2O3 MPs/PDA-RGO/SPCE sensor. Under the optimized conditions, the sensor demonstrated a lower detection limit (0.0042 μM), a limit of quantification (0.0078 μM), good sensitivity (2.24 μA μM-1 cm2), a wide linear range (0.019-190.7 and 212.7-1649 μM), and pinpoint specificity. The efficacy of the sensor is additionally validated through the accurate identification of TCP residues in water, soil, and food samples.

Bio-mineralized tin/bismuth oxide nanoparticles with silk fibroins for efficient electrochemical detection of 2-nitroaniline in river water samples

In recent years, the usage of nitroaniline has played a vital role in pharmaceutical formulations as it is a crucial ingredient in the synthesis of pesticides and dyes. However, the level of nitroaniline existing in industrial waste keeps rising the environmental contamination. Thus, monitoring of active nitro-residuals becomes more significant in reducing the toxicity of the ecosystem. Therefore, we have taken an attempt to evaluate the hazardous pollutant 2-nitroaniline (2-NA) using the electrocatalyst viz., tin-doped bismuth oxide inserted on a biopolymer silk fibroin composite modified glassy carbon electrode (Sn-Bi₂O₃/SF@GCE). The Sn-Bi₂O₃/SF nanocomposite was synthesized through hydrothermal and co-precipitation methods. The physicochemical properties of the prepared Sn-Bi₂O₃/SF hybrid composite were examined by conventional microscopy and spectroscopic techniques like FE-SEM, HR-TEM, XRD, FTIR, Raman, and XPS. Furthermore, the bio-mineralized Sn-Bi₂O₃/SF@GCE displayed a wide linear range (0.009 μM-785.7 μM) and a lower detection limit (3.5 nM) with good sensitivity for 2-NA detection under the optimum conditions. The result shows that the Sn-Bi₂O₃/SF-modified GCE has good reproducibility, repeatability, and excellent selectivity for 2-NA detection in the presence of other co-interfering compounds. Moreover, the practical applicability of Sn-Bi₂O₃/SF@GCE sensors was investigated for the effective detection of 2-NA in real river water samples, revealing good recovery results.

Molecular docking analysis of long-chain alkanes with the β-lactamase BEL-1 from P. aeruginosa

Pseudomonas aeruginosa is a gram-negative opportunistic bacterium that is a concern worldwide due to its innate antibiotic resistance properties. This warrants the development of non-antibiotic compounds that can potentially address the growing concern. Therefore, it is of interest to document the molecular docking analysis data of three long-chain alkanes, namely, eicosane, triacontane, and nonadecane with β-lactamase BEL-1. Data shows that nonadecane have good binding features and drug-likeness when compared to triacontane and nonadecane. It is well known that nonadecane is a compound that is abundantly available from natural resources for further consideration.

Highly exfoliated functionalized MoS2 with sodium alginate-polydopamine conjugates for electrochemical sensing of cardio-selective β-blocker by voltammetric methods

Molybdenum disulfide (MoS₂) surface functionalization was performed with a catechol-containing polymer sodium alginate (SA) and dopamine (DA) through simultaneous MoS₂ exfoliation and self-polymerization of DA. The MoS₂/SA-PDA nanocomposite was characterized using spectroscopic, microscopic, and electroanalytical techniques to evaluate its electrocatalytic performance. The electrocatalytic behavior of the MoS₂/SA-PDA nanocomposite modified electrode for the detection of acebutolol (ACE), a cardio-selective β-blocker drug was explored  through cyclic voltammetric and differential pulse voltammetric techniques. The influence of scan rate, concentration, and pH value on the oxidation peak current of ACE was investigated  to optimize the deducting condition. The electrochemical activity of the MoS₂/SA-PDA nanocomposite electrode was attributed to the existence of reactive functional groups being contributed from SA, PDA, and MoS₂ exhibiting a synergic effect. The MoS₂/SA-PDA nanocomposite modified electrode exhibits admirable electrocatalytic activity with a wide linear response range (0.009 to 520 μM), low detection limit (5 nM), and high sensitivity (0.354 μA μM^-1 cm^-2) also in the presence of similar (potentially interfering) compounds. The fabricated MoS₂/SA-PDA nanocomposite modified electrode can be useful for the detection of ACE in pharmaceutical analysis.

An electrochemical platform for the selective detection of azathioprine utilizing a screen-printed carbon electrode modified with manganese oxide/reduced graphene oxide

Scheme representing the electro-reduction of AZT at Mn₂O₃–rGO/SPCE.