An investigation of the synergistic effect between magnetite nanoparticles and polypyrrole in nanostructured layer‐by‐layer films

Abstract

In this paper, we report the controlled fabrication of layer-by-layer (LbL) films deposited on gold substrates with three different supramolecular architectures using polypyrrole (Ppy) and magnetite nanoparticles (Fe 3 O 4-np), besides conventional poly(allylamine hydrochloride) (PAH) e poly(vinyl sulfonic acid) (PVS) polyelectrolytes, demonstrating the synergistic effect between Ppy and Fe 3 O 4-np such as a result of their interaction. Modified gold electrodes were analyzed by contact angle (wettability), surface plasmon resonance (SPR), raman spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The (Fe 3 O 4-np/Ppy) 3 architecture was also evaluated by scanning electron microscopy. The modified gold electrodes present more homogeneous covering, higher electron transfer and a decrease of resistance with the incorporation of the nanostructured materials such as Ppy and Fe 3 O 4-np forming (Fe 3 O 4-np/Ppy) 3 LbL film. The results carried out in this study suggest that the (Fe 3 O 4-np/Ppy) 3 LbL film can be applied as a possible electrochemical or optical non-enzymatic sensor for analytical detection.

Simultaneous Determination of Catechol and Paraquat Using a Flexible Electrode of PBAT and Graphite Modified with Gold Nanoparticles and Copper Phthalocyanine (g-PBAT/AuNP/CuTsPc) LbL Film

“…The lower value of contact angle attributed to LbL film was expected because of both materials (PAH and CuTsPc) present hydrophilic characteristics due to numerous hydrogen bonding interactions among amine groups (−NH) corresponding to PAH polyelectrolytes and hydroxyl (−OH) groups of water. 23,36 This modification provided a better interaction between the sensor and the aqueous medium in which measurements were taken. This could be verified by the better electrochemical response of functionalized sensor when compared to sensor without functionalization, Fig.…”

“…The objective of this work was to develop an electrochemical sensor produced from a mixture of poly (butylene adipate-co-terephthalate) (PBAT) and graphite that was later functionalized with a self-assembled film of tetrasulfonic copper phthalocyanine (CuTsPc) and gold nanoparticles (AuNPs). In addition to the use of polymer and graphite as low-cost and accessible materials, the modification was carried out using the LbL films, which consisted of alternate deposition of oppositely charged materials, 22,23 using minimal amounts of materials, allowing the production of a sensor with properties such as low cost, good stability, fast response time, low detection limit and good selectivity for some possible interferences.…”