Selective and highly sensitive measurement of H₂O₂ and organic hydroperoxides with PtNP/Poly(Brilliant Green)/SPCE

This research presents a novel electrochemical approach for the selective measurement of hydrogen peroxide and organic hydroperoxides, which is pivotal in many fields. The study details the development of an advanced sensor using a one-pot, one-step synthesis to embed platinum nanoparticles within a 3D-polymeric matrix of poly (brilliant green) on screen-printed carbon electrodes. The modified surfaces were characterized using scanning and transmission electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results obtained by amperometry showed that, at 0.1 V, only H₂O₂ produced an electrochemical signal, while, at higher potential (0.5 V), all the hydroperoxides tested exhibited an electrochemical signal. Sensitivities obtained for H₂O₂ by flow injection analysis were 431 ± 3 and 465 ± 4 μC mM^-1 at 0.1 and 0.5 V, respectively, with detection limits (S/N = 3) 116 and 30 nM, respectively. For organic hydroperoxides, sensitivities ranged from 22.3 to 32.6 μC mM^-1 at 0.5 V, and limits of detection from 1.15 to 5.95 μM. Chemometric analysis indicated the sensor can satisfactorily measure H₂O₂ in the presence of the organic hydroperoxides herein analysed. The proposed sensor showed excellent properties in terms of repeatability, reproducibility and stability, with minimal interference. The reliability of the sensor was verified by measuring hydroperoxides spiked in aqueous extracts from real air quality monitoring filters. These features highlight the suitability of the sensor for hydroperoxide measurement and underscore its reliability as a practical tool for real-world applications.