Fabrication of Coral-like Polyaniline/Continuously Reinforced Carbon Nanotube Woven Composite Films for Flexible High-Stability Supercapacitor Electrodes

Reagent-free anti-fouling electrochemical immunosensor based on AL-BSA/AuNPs/PANI coating for the point-of-care detection of C-reactive protein in plasma and whole blood

Developing the portable CRP detection technologies that are suitable for point-of-care (POC) and primary care management is of utmost importance, and advancing the electrochemical immunosensors hold promise for POC implementation. Nevertheless, non-specific adsorption of numerous interfering proteins in complex biological media contaminates immunosensors, thereby restricting the reliability in detection efficacy. In this study, a three-dimensional flower-leaf shape amyloid bovine serum albumin/gold nanoparticles/polyaniline (AL-BSA/AuNPs/PANI) coating on the surface of the electrode was developed, which demonstrated strong anti-adsorption properties against bovine serum albumin, plasma, and cells. The immunosensor exhibited a good linear relationship to CRP response, featuring a detection limit of 0.09 μg/mL, consistent with clinical reference range. In addition, the CRP immunosensor demonstrated excellent specificity in other inflammation-related proteins and commendable anti-interference performance for CRP detection in plasma and whole blood tests. Importantly, by combining the development of a USB flash disk-type portable electrochemical workstation with a reagent-free mode, the developed CRP electrochemical immunosensor delivered ideal results in clinical samples. The anti-fouling performance, sensitivity and specificity of the immunosensor, as well as its flexible test modes in clinical samples, provide important scientific basis for developing POC detection technologies of vital biomarkers in complex biological media.

Recent Progress in Polyaniline and its Composites for Supercapacitors

Polyaniline (PANI) has piqued the interest of nanotechnology researchers due to its potential as an electrode material for supercapacitors. Despite its ease of synthesis and ability to be doped with a wide range of materials, PANI's poor mechanical properties have limited its use in practical applications. To address this issue, researchers investigated using PANI composites with materials with highly specific surface areas, active sites, porous architectures, and high conductivity. The resulting composite materials have improved energy storage performance, making them promising electrode materials for supercapacitors. Here, we provide an overview of recent developments in PANI-based supercapacitors, focusing on using electrochemically active carbon and redox-active materials as composites. We discuss challenges and opportunities of synthesizing PANI-based composites for supercapacitor applications. Furthermore, we provide theoretical insights into the electrical properties of PANI composites and their potential as active electrode materials. The need for this review stems from the growing interest in PANI-based composites to improve supercapacitor performance. By examining recent progress in this field, we provide a comprehensive overview of the current state-of-the-art and potential of PANI-based composites for supercapacitor applications. This review adds value by highlighting challenges and opportunities associated with synthesizing and utilizing PANI-based composites, thereby guiding future research directions.

Proton is Essential or Not: A Fresh Look on Pseudocapacitive Energy Storage of PANI Composites

Protonation has been considered essential for the pseudocapacitive energy storage of polyaniline (PANI) for years, as proton doping in PANI chains not only activates electron transport pathways, but also promotes the proceeding of redox reactions. Rarely has the ability for PANI of storing energy without protonation been investigated, and it remains uncertain whether PANI has pseudocapacitive charge storage properties in an alkaline electrolyte. Here, this work first demonstrates the pseudocapacitive energy storage for PANI without protonation using a PANI/graphene composite as a model material in an alkaline electrolyte. Using in situ Raman spectroscopy coupled with electrochemical quartz crystal microbalance (EQCM) measurements, this work determines the formation of -N= group over potential on a PANI chain and demonstrates the direct contribution of OH- in the nonprotonation type of oxidation reactions. This work finds that the PANI/graphene composite in an alkaline electrolyte has excellent cycling stability with a wider operation voltage of 1 V as well as a slightly higher specific capacitance than that in an acidic electrolyte. The findings provide a new perspective on pseudocapacitive energy storage of PANI-based composites, which will influence the selection of electrolytes for PANI materials and expand their application in energy storage fields.