We describe a simple strategy to modify zeolitic imidazolate framework-8 (ZIF-8) using polyaniline (PANI) via a controlled interfacial polymerization method, without using a template, to synthesize ZIF-8/PANI nanocomposites. Our method avoids the agglomeration of ZIF-8/PANI, boosts the utilization of active materials, and exposes more active sites, and hence, it is advantageous to facile electron transfer. Because of its unique hierarchical structure, ZIF-8/PANI has a high surface area (610.8 m2·g–1) and the ZIF-8/PANI electrode exhibited a capacitance value of 395.4 F·g–1 at 0.2 A·g–1, which is the highest among the metal–organic framework (MOF)-based composites reported to date. A solid-state asymmetric supercapacitor (SASC) fabricated with ZIF-8/PANI as the electrode showed good capacitive behavior over a wide potential window from 0 to 2.5 V without nonaqueous electrolytes. It exhibited a specific areal capacitance of 28.1 mF·cm–2 at 0.1 mA·cm–2, which is much higher than the values reported for other MOF-based supercapacitors. The SASC also possessed a high energy density (3.2 μW h·cm–2) and power density (1.1 mW·cm–2), good cycling stability, and flexibility. These characteristics make our ZIF-8/PANI nanocomposite an excellent MOF-based electrode for highly flexible and lightweight energy storage applications.

Consumption of cranberries is associated with the putative effects of preventing urinary tract infections (UTIs). Cranberry proanthocyanidins (PAC) contain unusual double A-type linkages, which are associated with strong interactions with surface virulence factors found on UTI-causing bacteria such as extra-intestinal pathogenic Escherichia coli (ExPEC), depicting in bacterial agglutination processes. In this work, we demonstrated the efficacy of cranberry PAC (200 μg/mL) to agglutinate ExPEC (5.0×108 CFU/mL) in vitro as a selective interaction for the design of functionalized biosensors for potential detection of UTIs. We fabricated functionalized screen-printed electrodes (SPEs) by modifying with PAC-polyaniline (PANI) nanocomposites and tested the effectiveness of the PAC-PANI/SPE biosensor for detecting the presence of ExPEC in aqueous suspensions. Results indicated that the PAC-PANI/SPE was highly sensitive (limit of quantification of 1 CFU/mL of ExPEC), and its response was linear over the concentration range of 1–70,000CFU/mL, suggesting cranberry PAC-functionalized biosensors are an innovative alternative for the detection and diagnosis of ExPEC-associated UTIs. The biosensor was also highly selective, reproducible, and stable.

Monodispersed colloidal gold nanoparticles (AuNPs) were synthesized by an easy, cost-effective, and eco-friendly method for electrochemical detection of As(iii).