ENGINEERING of a NOVEL SCREEN-PRINTED ELECTRODE MODIFIED by Pt DECORATED SINGLE WALLED CARBON NANOTUBE NANOHYBRID for MONITORING SULFITE in REAL SAMPLES: A NEW APPROACH to a SUSTAINABLE ENVIRONMENT and HEALTH

Authors : Ceren KARAMAN

Pages : 228-244

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Publication Date : 2022-09-30

Article Type : Research Paper

Abstract :Sensitive and selective monitoring of sulfite anions, a food additive, in real-time applications is still a challenging issue to be solved. It is crucial to engineering highly selective and sensitive, facile, and low-cost analytical tools for monitoring trace levels of sulfite anions in real samples. In light of this, the goal of this work was to tailor a Pt-decorated single-walled carbon nanotubes (Pt@SWCNTs) nanohybrid to be utilized in the engineering of an electrochemical sensor to monitor sulfite anions in real samples. The microstructural features of the fabricated nanocatalysts were assessed via transmission electron microscope (TEM), whereas the electrochemical characteristics were enlightened via differential pulse voltammetry (DPV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) methods. The screen-printed electrode (SPE), as an electrochemical sensor, was modified via Pt@SWCNTs nanocatalysts and the resultant electrochemical sensor (Pt@SWCNTs/SPE) was employed as a powerful electroanalytical tool for monitoring sulfite in the concentration range of 0.1 - 250 µM with a limit of detection value of 10 nM. The optimal catalyst concentration was determined as 9.0mg Pt@SWCNTs, and the pH 5.0 was selected as the optimal pH. At the optimal operating conditions, it was observed that the oxidation current of sulfite was enhanced almost 2.53-fold, and the oxidation potential of it diminished ca.50 mV at the surface of Pt@SWCNTs/SPE in comparison to bare SPE. The sulfite anions monitoring ability of proposed Pt@SWCNTs/SPE was further confirmed in red wine and tap water samples by the standard addition method, and the recovery range was determined as 98.5 – 102.3%. The enhanced electrochemical performance of the fabricated electrochemical sensor compared to bare SPE was directly ascribed to the coupled effects of co-existing Pt nanoparticles and SWCNTs architecture, which facilitated both the electron transfer and mass transfer. This works paws the way for tailoring of hybrid nanocatalysts to be utilized in electrochemical engineering applications for sustaining the environment and health.
Keywords : sulfite, electrochemical sensor, monitoring, Pt@SWCNT, screen printed electrode