Facile engineering of gadolinium cobaltite anchored on functionalized carbon black as dynamic electrocatalyst for ultra-sensitive detection of nitroaromatic drug.

There has been a significant increase in the production and use of antibiotic drugs. However, the overuse and improper disposal of nitro-based antibiotics pose a significant threat to human health and the ecosystem. Specifically, the residues of antibiotic drugs such as nitrofurantoin (NFT) are dangerous to public health and pose a threat to the environment. In this study, we prepared a novel nanocomposite consisting of gadolinium cobaltite embedded functionalized carbon black (GdCoO3/f-CB) via a simple hydrothermal technique and utilized this nanocomposite as an electrode material for the electrochemical detection of NFT. The structural and morphological properties of the GdCoO3/f-CB nanocomposite was analyzed using a range of techniques, including XRD, Raman, XPS, EDX-Mapping, and HR-TEM. The electrocatalytic activity of the GdCoO3/f-CB nanocomposite was investigated using both CV and DPV techniques for the detection of NFT. Our results demonstrated that the prepared GdCoO3/f-CB nanocomposite delivered the excellent activities toward the detection of NFT at an extremely low limit of detection (LOD) of 2 nM and exhibited high sensitivity of 31 µA·µM-1·cm-2. Additionally, the proposed NFT sensor using GdCoO3/f-CB nanocomposite provided excellent reproducibility, repeatability, and selectivity, even in the presence of interfering molecules such as metal ions, biomolecules, and similar nitro compounds. These findings suggest that the GdCoO3/f-CB nanocomposite provides significant potential for the electrochemical detection of antibiotic drug residues for public health and the environment.

Highly stretchable transparent bar coated Ag NW/PEDOT:PSS hybrid electrode for wearable and stretchable devices.

In this study, we demonstrated poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) as a composite with Ag nanowire (Ag NW) to enhance the stretchability of the Ag NW network electrode. The composite Ag NW/PEDOT:PSS hybrid ink (AP ink) was prepared at a ratio of 1 : 10, 1 : 20, and 1 : 30, respectively and bar coated on polyurethane substrate. The different ink ratios were studied and optimized with a sheet resistance of 14.93 Ω sq-1. and a transmittance of 88.6% showing a high performance in mechanical stress tests such as bending, folding, rolling, twisting, and stretching. It also showed a conductive bridge effect where the PEDOT:PSS acted as an anchor or support to Ag NW during mechanical strain and PEDOT:PSS also enhanced the electrical conductivity of the Ag NW. Therefore, to prove the real time performance of the electrode as a wearable device, we fabricated transparent electroluminescence devices and thin film heater devices which are highly flexible and demonstrated excellent performance proving that the AP electrode is more suitable candidate for future wearable transparent devices.

High-performance flexible transparent micro-supercapacitors from nanocomposite electrodes encapsulated with solution processed MoS2 nanosheets.

Two-dimensional molybdenum disulfide (MoS2) nanosheets have emerged as a promising material for transparent, flexible micro-supercapacitors, but their use in electrodes is hindered by their poor electrical conductivity and cycling stability because of restacking. In this paper, we report a novel electrode architecture to exploit electrochemical activity of MoS2 nanosheets. Electrochemically exfoliated MoS2 dispersion was spin coated on mesh-like silver networks encapsulated with a flexible conducting film exhibiting a pseudocapacitive behavior. MoS2 nanosheets were electrochemically active over the whole electrode surface and the conductive layer provided a pathway to transport electrons between the MoS2 and the electrolyte. As the result, the composite electrode achieved a large areal capacitance (89.44 mF cm-2 at 6 mA cm-2) and high energy and power densities (12.42 µWh cm-2 and P = 6043 µW cm-2 at 6 mA cm-2) in a symmetric cell configuration with 3 M KOH solution while exhibiting a high optical transmittance of ~80%. Because the system was stable against mechanical bending and charge/discharge cycles, a flexible micro-supercapacitor that can power electronics at different bending states was realized.