Microwave plasma treated Sn/SnO2 and graphite nanocomposites to synergistically promote electrochemical sensing performance toward dopamine and uric acid

BACKGROUND

The investigation of biomolecules is essential due to abnormalities in biological metabolism in the human body. Dopamine (DA) and uric acid (UA) are important chemicals that coexist in biological systems and play crucial roles in various physiological processes related to human metabolism. This study explores the application of carbon and SnO2 nanoparticles for DA and UA sensing, focusing on the preparation of Sn/SnO2 nanocomposites through electrospinning and plasma treatment. The research aims to measure these concentrations quickly and accurately, offering advantages such as low manufacturing costs and environmental friendliness.

RESULT

This study presents a novel Sn/SnO2 nanocomposites as an electrocatalyst for the detection of dopamine (DA) and uric acid (UA) levels. Sn/SnO2 nanocomposites were effectively obtained by argon microwave plasma (ArMP) treatment, a dry and green process, on electrospun fibers containing SnCl2 within 120 s. The resultant Sn/SnO2 nanocomposites provide excellent electrochemical catalytic effects to quantify the levels of DA and uric acid UA, which are the two important physiological molecules. To further incorporate graphite into ArMP-Sn/SnO2 can modulate precise differentiation of the oxidation peaks of DA, UA, and ascorbic acid (AA), solving the problems of overlapped oxidation potential among biomolecules. The as-established nanocomposites revealed excellent applicability to be incorporated onto difference substrates including gold electrode (AuE), screen-printed carbon electrodes (SPCE), and flexible carbon electrodes (FCE), providing great potential for building point-of-care sensing platform.

SIGNIFICANCE

The 1%g-120s-ArMP-Sn/SnO2@AuE resulting the highest sensing performance for DA and UA, which the linear detection range was 0.1-400 μM and 0.1-900 μM, with sensitivity of 473.72 and 169.21 μA/mM.cm2, and LOD 0.003 and 0.010 μM, respectively. Additionally, in the areal human fluid matrix the sensor obtains a recovery rate between 95.28 % and 102.72 % with a high selectivity (less than 5 %) upon the presence of common interferences in body fluid.

Electrodeposition of Cu on PEDOT for a Hybrid Solid-State Electronic Device

Conductive polymers are nowadays attracting great attention for their peculiar mechanical, electrical and optical proprieties. In particular, PEDOT can be used in a wide range of innovative applications, from electroluminescent devices to photovoltaics. In this work, the electrochemical deposition of 3,4 ethylenedioxythiophene (EDOT) was performed on various substrates (ITO, thin films of gold and palladium on silicon wafers) by means of both potentiostatic and potentiodynamic techniques. This was intended to further expand the applications of electrochemically deposited PEDOT, particularly regarding the preparation of thin films in tight contact with electrode surfaces. This allows one to obtain systems prone to be used as electrodes in stacked devices. Chronoamperometric experiments were performed to study the nucleation and growth process of PEDOT. SEM, ESEM and AFM analysis allowed the characterization of the morphology of the polymeric films obtained. Raman and visible spectroscopy confirmed the high-quality of the coatings on the different substrates. Then, the PEDOT films were used as the base material for the further electrodeposition of a copper layer. In this way, a hybrid electronic device was obtained, by using electrochemical methods only. The high conductivity and ohmic behavior of the device were confirmed over a wide range of frequencies with electrical impedance spectroscopy analysis.