Electroactive MnO₂ nanorods-integrated grafted pectic acid nanocomposite for enzyme-free hydrogen peroxide...

Grafting pectic acid (PecA) is fueled by free radical copolymerization of acrylic acid (AcA) and acrylamide (AAm), [PecA-g-poly (AAm-co-AcA)], embedded with manganese dioxide-nanorods (MnO₂-NRs) produced an inventive nanocomposite, [PecA-g-poly (AAm-co-AcA)/MnO₂-NRs]. Fourier-transform infrared (FT-IR) spectroscopic analysis, thermal gravimetric (TG) measurement, scanning and transmission electron microscopes (SEM and TEM) analyses, in addition to X-ray diffraction (XRD), alongside cyclic voltametric (CV) measurements with spectroscopic investigation of electrochemical impedance (EIS), were applied for evaluating PecA-g-poly (AAm-co-AcA)/MnO₂-NRs. Based on the TEM images, MnO₂-NRs have a width size extent from 9 to 33 nm, PecA-g-poly (AAm-co-AcA) has cluster nanoporous framework shapes with a particle size close to 45 nm, and observative nanorods covered the nanoparticles for PecA-g-poly (AAm-co-AcA)/MnO₂-NRs with the polymeric particle's diameters between 21 and 50 nm. The MnO₂-based nanocomposite showed significantly higher electrical capacitance than its grafted copolymer, PecA-g-poly (AAm-co-AcA). Screen-printed carbon electrode (SPCE) modification using PecA-g-poly (AAm-co-AcA)/MnO₂-NRs was examined for its ability to detect hydrogen peroxide (H₂O₂) effectively. Across a range of 0.1 to 1000 μM, it showed remarkable stability, reproducibility, rapid, linear sensitivity, and instantaneous electron transmission. Furthermore, the sensor demonstrated good recovery rates while analysing milk and salami samples. This nanocomposite is thus suitable for detecting hydrogen peroxide as one of reactive oxygen species and its decomposition due to the markedly improved electrical properties.