Preparation of ultra-thin polypyrrole nanosheets decorated with Ag nanoparticles and their application in hydrogen peroxide detection

Water-Chloroform Interface Assisted Microstructure Tuning of Polypyrrole-Silver Sheets

The liquid-liquid interface of two immiscible solvents remarkably controls the morphology of polymeric nanostructures as compared to the polymerization in single solvent systems. The polymerization of pyrrole in the water-chloroform medium using silver nitrate (AgNO₃) as oxidant yields polypyrrole/silver (PPy/Ag) sheets. The water-chloroform interface acts as a template for the growth of PPy/Ag hybrids into sheets by preventing the secondary growth of silver associated pyrrole oligomers in a three-dimensional (3-D) manner. On the contrary, the 3-D growth of pyrrole oligomers into spherical shapes at the water-chloroform interface is observed when ammonium persulfate (APS) is used as the oxidant. Transmission electron microscopic and scanning electron microscopic images reveal the sheetlike morphology of PPy/Ag with a relatively uniform distribution of Ag NPs (∼100 nm) on PPy sheets. The ratio of aqueous-organic bisolvent and the concentration/type of oxidant have a distinct effect on morphology, crystallinity, and electrical properties of PPy/Ag sheets. The dispersed PPy/Ag sheets are stable in moderately polar solvents up to 2 weeks. The electrochemical behavior of PPy/Ag sheets is confirmed by H₂O₂ sensing capability through cyclic voltammetry experiments. The antibacterial activity toward E. coli and S. aureus is quantitatively assessed using the minimum bactericidal concentration (MBC) determination.

Nanocomposite based on restacked crystallites of β-NiS and Ppy for the determination of theophylline and uric acid on screen-printed electrodes

We synthesized calcinated β-NiS with a highly crystalline porous nature and mixed it with Ppy to prepare a nanocomposite, which exhibited high electrocatalytic activity and this was then used to detect theophylline and uric acid with high sensitivity and stability.

A sensitive electrochemical Hg2+ ions sensor based on polypyrrole coated nanospherical platinum

We report the synthesis and characterization of polypyrrole coated on nanospherical platinum (Pt/PPy NSs) composites for the detection of mercury ions.

Fabrication of polypyrrole nanoplates decorated with silver and gold nanoparticles for sensor applications

The PPyNPT–Ag and PPyNPT–Au nanohybrids fabricated by self-assembly process exhibit excellent electrocatalytic activity toward H₂O₂ and DA, respectively.

A sensitive dopamine biosensor based on ultra-thin polypyrrole nanosheets decorated with Pt nanoparticles

A Pt/UltraPPy modified glassy carbon electrode is a highly sensitive new sensor for the detection of dopamine.

Dispersed CuO nanoparticles on a silicon nanowire for improved performance of nonenzymatic H2O2 detection

A finely dispersed CuO nanoparticle electrocatalyst on a silicon nanowire (SiNW) was achieved via a designed, precursor-mediated strategy by combining metal-assisted chemical etching, electroless deposition, and thermal oxidation. The CuO assembled on silicon nanowires (CuO-SiNWs) showed a competent sensitivity of 22.27 μA/mM, a wider linear range from 0.01 to 13.18 mM, and a comparable detection limit of 1.6 μM (3S/N) for nonenzymatic H2O2 detection. The archetype sensor also demonstrated eligible selectivity against common interfering species. By the introduction of the SiNW carrier, which led to mitigated conglomeration of the electrocatalyst and a favorable microstructure of the electrocatalyst-carrier system, improved signal-concentration linearity and higher electrocatalyst utilization efficiency were obtained with CuO-SiNWs. These results demonstrated the feasibility of the synthetic strategy and the potential of the nanocomposite as a promising candidate for H2O2 sensing.