Graphene and Chitosan Composite Film Modified Electrode as a Sensitive Voltammetric Sensor for Tyrosine Detection in Food and Biological Samples

Abstract

A voltammetric sensor made from a graphene and chitosan modified glassy carbon electrode (GR-CTS/GCE) was fabricated for accurate analysis of tyrosine (Tyr) in both food and biological samples. The surface morphology of the electrode and the properties of the electrode-electrolyte interface were determined by scanning electron microscopy and cyclic voltammetry. Compared with a bare GCE, the synergistic effect of GR and CTS is obvious. The peak current increases 35.6 times. The experimental conditions were optimized by second derivative linear sweep voltammetry (SDLSV) and Tyr was quantitatively analyzed on the electrode. The study shows that the oxidation peak current of Tyr obtained in 0.1 M pH 2.7 phosphate buffer is proportional to its concentration between 0.006-0.8 and 0.8-10.0 μM, with the low detection limit being 4.0 nM (signal/noise = 3). Excellent anti-interference ability was demonstrated by investigating the voltammetric response of Tyr in mixtures containing other biomolecules. In addition, the sensor exhibited good stability and repeatability. Through the detection of Tyr in milk and serum samples, the effectiveness of the sensor was studied, and the results were satisfactory.

The Modified Glassy Carbon Electrode by MWCNTs-PLL to Detect Both Paracetamol and Ibuprofen in Human Biological Fluid

“…Regardless of this, it is worth noting that the electroanalytical techniques have several unique characteristics for drug quality monitoring such as great sensibility and selectivity, cheapness, and clarity and these have a higher analytical frequency when being compared to the enormous previous approaches, this is proven through several updated works. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] There are a few reports about determining PAR and IBU, but, up to this point, there are seldom published on determining simultaneously these substances in biological fluid samples applying electrochemical approaches. Therefore, this report could be seen as the updated information to refer for the next research and the valuable material to scientists for applying to the determination of PAR and IBU in the medication.…”