Toll-like receptor-immobilized carbon paste electrodes with plasma functionalized amine termination: Towards real-time electrochemical based triaging of gram-negative bacteria.

Chronic wounds caused due to bacterial biofilms are detrimental to a patient, and an immediate diagnosis of these bacteria can aid in an effective treatment, which is still an unmet clinical need. An instant and accurate identification of bacterial type could be made by utilizing the Toll-Like Receptors (TLRs) combined with Myeloid Differentiation factor 2 (MD-2). Given this, we have developed an electrochemical sensing platform to identify the gram-negative (gram-ve) bacteria using TLR4/MD-2 complex. The nonthermal plasma (NTP) technique was utilized to functionalize amine groups onto the carbon surface to fabricate cost-effective carbon paste working electrodes (CPEs). The proposed electrochemical sensor platform with a specially engineered electrochemical cell (E-Cell) identified the Escherichia coli (E. coli) in a wide linear range of 1.5×10° - 1.5×106 C.F.U./mL, accounting for a very low detection limit of 0.087 C.F.U./mL. The novel and cost-effective sensor platform identified gram-ve bacteria predominantly in a mixture of gram positive (gram+ve) bacteria and fungi. Further, towards real-time detection of bacteria and point-of-care (PoC) applications, the effect of the pond water matrix was studied, which was minimal, and the sensor could identify E. coli concentrations selectively, showing the potential application of the proposed platform towards real-time bacterial detection.

Plasma Functionalized Carbon Interfaces for Biosensor Application: Toward the Real-Time Detection of Escherichia coli O157:H7.

Nonthermal plasma, a nondestructive, fast, and highly reproducible surface functionalization technique, was used to introduce desired functional groups onto the surface of carbon powder. The primary benefit is that it is highly scalable, with a high throughput, making it easily adaptable to bulk production. The plasma functionalized carbon powder was later used to create highly specific and low-cost electrochemical biosensors. The functional groups on the carbon surface were confirmed using NH3-temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) analysis. In addition, for biosensing applications, a novel, cost-effective, robust, and scalable electrochemical sensor platform comprising in-house-fabricated carbon paste electrodes and a miniaturized E-cell was developed. Biotin-Streptavidin was chosen as a model ligand-analyte combination to demonstrate its applicability toward biosensor application, and then, the specific identification of the target Escherchia coli O157:H7 was accomplished using an anti-E. coli O157:H7 antibody-modified electrode. The proposed biosensing platform detected E. coli O157:H7 in a broad linear range of (1 × 10-1-1 × 106) CFU/mL, with a limit of detection (LOD) of 0.1 CFU/mL. In addition, the developed plasma functionalized carbon paste electrodes demonstrated high specificity for the target E. coli O157:H7 spiked in pond water, making them ideal for real-time bacterial detection.

Promising Utilization of CO2 for Syngas Production over Mg2+- and Ce2+-Promoted Ni/γ-Al2O3 Assisted by Nonthermal Plasma.

Dry reforming of methane is conducted in a catalyst packed-bed dielectric barrier discharge (DBD) reactor aiming to improve the reaction efficiency. The MgO- and CeO2-promoted Ni/γ-Al2O3 catalyst is tested to carry out the reaction. An interesting observation is that Ni/MgO_Al2O3 integration provides ∼35 and 13% conversion of CH4 and CO2, respectively. The highest syngas ratio of 0.94 is obtained with Ni/MgO_Al2O3, whereas the ratio is only 0.57 with Ni/CeO2_Al2O3 and 0.64 with bare DBD. In addition, Ni/CeO2_Al2O3 offers the highest selectivity (68%) of CO due to the oxygen buffer property of CeO2. Finally, the optimal acid/base property is highly desirable for the dry reforming reaction.

A facile method to decompose CO2 using a g-C3N4-assisted DBD plasma reactor.

The present study accomplishes the partial reduction of CO2 to carbon monoxide in a dielectric barrier discharge (DBD) reactor packed with g-C3N4 and TiO2 or ZnO mixed with g-C3N4. Typical results indicate that the ZnO + g-C3N4 packed reactor provides ~12% CO2 conversion at SIE of 4.8 J/mL, whereas DBD yields only ~7.5% conversion under the same experimental conditions. The best performance of the ZnO integrated system is due to the presence of more basic sites than those of the TiO2 packed system, which enables effective adsorption of acidic CO2 on its surface. The highest energy efficiency of 1.106 mmol/kJ is achieved with 5% ZnO + g-C3N4 at SIE of 4.8 J/mL, whereas DBD exhibits only 0.746 mmol/kJ under the same conditions. Notably, catalyst packing also enables the highest carbon balance of ~97%.

Ag(I)-Catalyzed Domino Cyclization-Addition Sequence with Simultaneous Carbonyl and Alkyne Activation as a Route to 2,2'-Disubstituted Bisindolylarylmethanes.

An efficient synthesis of symmetrical 3, 3'-bisindolylarylmethanes with various substituents on the indole moiety has been developed by Ag(I)-catalyzed cycloisomerization and an deoxygenative addition sequence on o-alkynylanilines and aryl aldehydes. Ag(I) is proposed to activate alkyne unit and carbonyl moiety simultaneously leading to a domino first 5-endo-dig indole annulation, addition to C═O, second indole annulation, and its dehydroxylative addition.