A Simple Electropolymer Based Voltammetric Sensor for the Simultaneous Determination of Melanoma Biomarkers–L-Dopa and L-Tyrosine

Abstract

This article describes the development of a simple electropolymer based voltammetric sensor for the sensitive determination of melanoma biomarkers, L-Dopa and L-Tyrosine. A glassy carbon electrode modified with poly para toluene sulphonic acid which is an excellent electro-catalyst for the oxidation of L-Dopa and L-Tyrosine enables their simultaneous determination. Fabrication, characterization, calibration, real sample applicability as well as consistency in performance of the sensor are discussed in detail. For the simultaneous determination, linear calibration plot has been obtained in two dynamic ranges for both the analytes. For L-Dopa it is from 9.00 × 10−5 M to 2.00 × 10−5 M and from1.00 × 10−5 to 1.00 × 10−6 M and for L-Tyrosine, 7.00 × 10−5 M to 2.00 × 10−5 M and from1.00 × 10−5 to 1.00 × 10−6 M are the two dynamic ranges. The recovery values obtained through spike recovery analysis demonstrates its practical application in real sample analysis.

Simultaneous Determination of Serotonin and Tryptamine Using Polyglutamic Acid-Silver Nanoparticles Composite Film Modified Glassy Carbon Electrode

“…11c). 32 The slope value, 0.9, which was determined from the log scan rate against log peak current plot of Tryp, is near to the theoretical value, 1 (Fig. 11d).…”

“…11b). This implies that the electron transfer between the modifier and ST is a diffusion-controlled 32 and the that for Tryp is an adsorption-controlled process. 26 The linear regression equations corresponding to the plots for ST and Tryp are given as I P = 6.39 × 10 -6 ν √ −4.70 × 10 -7 (R 2 = 0.99 & ν = scan rate) and I P = 1.35 × 10 -5 ν+8.18 × 10 -8 (R 2 = 0.99 & ν = scan rate), respectively.…”

“…This confirms that the number of protons transferred during the electrooxidation of both ST and Tryp is the same as that of the number of electrons transferred. 26,32 That means two electrons and protons are involved in the electrooxidation of ST, and one electron and proton are involved in the oxidation of Tryp. The linear regression equations obtained from the plot of E P versus pH for ST and Tryp are given as E P = −0.05 pH+0.75 (R 2 = 0.99) and E P = −0.05 pH+1.17 (R 2 = 0.98), respectively.…”

A Copolymer Based Voltammetric Sensor for the Simultaneous Determination of Neuroendocrine Tumour Biomarkers

“…POC devices are becoming a necessity for the routine monitoring of markers for diseases like cancer for the early diagnosis. 22,23 Hence electrochemical sensors for such biomarkers always remain a necessity in the field of diagnosis. Voltammetry is a widely used electrochemical technique which enables the simultaneous determination of multiple analytes.…”

Hydrogel Microneedle-Assisted Assay Integrating Aptamer Probes and Fluorescence Detection for Reagentless Biomarker Quantification

“…Our reagentless fluorescence assay for minimally invasive detection (RFMID) integrates a rapid and simple approach to link aptamer probes to the MeHA matrix. We demonstrate the application of our biosensor for ex vivo detection of four clinically important biomolecules: glucose, which is crucial to avoiding diabetic complications; adenosine triphosphate (ATP), an important molecule that provides energy to drive many processes in living cells; l -tyrosinamide, a mimic of l -tyrosine, which is a biomarker of metabolic syndrome and melanoma; , and thrombin, a proteinase that plays an imperative role in regulating hemostasis and maintaining blood coagulation systems . RFMID patches functionalized with aptamer probes can detect the analyte concentrations with high sensitivity and specificity.…”