Simple and Sensitive Electrochemical Determination of L-Tryptophan at Electrochemically Activated Glassy Carbon Electrode

Document Type : Research Article


1 Department of Chemistry, College of Natural Sciences, Jimma University, P. O. Box 378, Jimma, ETHIOPIA

2 Department of Chemistry, College of Natural Sciences, Jimma University, P. O. Box 378, Jimma, ETHIOPIAty

3 Chemistry Department, Faculty of Natural and Computational Science, Mettu University, Mettu, ETHIOPIA


Herein, we reported an Activated Glassy Carbon Electrode (AGCE) for the detection of L-tryptophan (Trp). AGCE was made by successive cyclic voltammetric potential scanning of glassy carbon electrode (GCE) from -1.5 V to 2.5 V in 0.1 M pH 7.0 phosphate buffer as a supporting electrolyte. The surface morphology of AGCE and Un-Activated Glassy Carbon Electrode (UGCE) was characterized by a Scanning Electron Microscope (SEM). The voltammetric sensing of Trp is carried out using Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV). The electrochemical properties of the AGCE and UGCE were also examined by CV and Electrochemical Impedance Spectroscopy (EIS). AGCE exhibited enhanced anodic peak current and less overpotential for the oxidation of Trp than UGCE. LSV was used for the quantitative determination of Trp. Two linear ranges were obtained for the determination of Trp using LSV from 2.5 μM – 20.0 μM and 2.0 μM100.0 μM. The limit of detection (3σ/m) was 0.098 μM.  The current method was successfully used to detect Trp in urine and healthy human serum.


Main Subjects

[6] Li J., Jiang J., Xu Z., Liu M., Tang S., Yang C., Qian D., Facile synthesis of Pd−Cu@Cu2O/N-RGO Hybrid and its Application for Electrochemical Detection of Tryptophan, Electrochim. Acta, 260: 526-535 (2018).
[7] Lian W., Ma D. J., Xu X., Chen Y., Wu Y. L., Rapid High-Performance Liquid Chromatography Method For Determination of Tryptophan in Gastric Juice, J. Dig. Dis., 13: 100-106 (2012).
[8] Kumar J. V., Karthik R., Chen S.-M., Marikkani S., Elangovan A., Muthuraj V., Green Synthesis of a Novel Flower-Like Cerium Vanadate Microstructure for Electrochemical Detection of Tryptophan in Food and Biological Samples, J. Colloid Interface Sci., 496: 78-86 (2017).
[10] Zhang L., Li Y., Zhou H., Li L., Wang Y., Zhang, Y., Determination of Eight Amino Acids in Mice Embryonic Stem Cells by Pre-Column Derivatization HPLC with Fluorescence Detection, J. Pharm. Biomed. Anal., 66: 356-358 (2012).
[11] Dario M.F., Freire T.B., Pinto C.A., Prado M.S., Baby A.R., Velasco M.V., Tryptophan and Kynurenine Determination in Human Hair by Liquid Chromatography. J. Chromatogr. B, 1065-1066: 59-62 (2017).
[12] Qiu H., Luo C., Sun M., Lu F., Fan L., Li X., Determination of L-Tryptophan Based on Graphene Oxide–Magnetite-Molecularly Imprinted Polymers and Chemiluminescence, Talanta, 98: 226-230 (2012).
[13] Lin Z., Chen X., Cai Z., Li P., Chen X., Wang X., Chemiluminescence of Tryptophan and Histidine in Ru(bpy)32+-KMnO4 Aqueous Solution, Talanta, 75: 544-550 (2008).
[14] Li H., Li F., Han C., Cui Z., Xie G., Zhang A., Highly Sensitive and Selective Tryptophan Colorimetric Sensor Based on 4,4-Bipyridine-Functionalized Silver Nanoparticles, Sensor. Actuat. B: Chem., 145: 194-199 (2010).
[17] Han J., Zhao J., Li Z., Zhang H., Yan Y., Cao D., Wang G., Nanoporous Carbon Derived From Dandelion Pappus as an Enhanced Electrode Material with Low Cost for Amperometric Detection of Tryptophan, J. Electroanal. Chem., 818: 149-156 (2018).
[19] Gautam J., Raj M., Goyal R. N., Determination of Tryptophan at Carbon Nanomaterials Modified Glassy Carbon Sensors: A Comparison, J. Electrochem. Soc., 167: 066504 (2020).
[20] Dekanski A., Stevanović J., Stevanović R., Nikolić B. Ž., Jovanović V. M., Glassy carbon Electrodes: I. Characterization and Electrochemical Activation. Carbon, 39: 1195-1205 (2001).
[21] Van der Linden W. E., Dieker J. W., Glassy Carbon as Electrode Material in Electro-Analytical Chemistry, Anal. Chim. Acta, 119: 1-24 (1980). 
[22] Bystron T., Sramkova E., Dvorak F., Bouzek K., Glassy Carbon Electrode Activation – A Way Towards Highly Active, Reproducible And Stable Electrode Surface, Electrochim. Acta, 299: 963-970 (2019).
[23] Altuner E.E., Ozalp V.C., Yilmaz M.D., Sudagidan M., Aygun A., Acar E.E., Tasbasi B.B., Sen F., Development of Electrochemical Aptasensors Detecting Phosphate Ions on TMB Substrate with Epoxy-Based Mesoporous Silica Nanoparticles, Chemosphere, 297: 134077 (2022).
[24] Altuner E.E., Ozalp V.C., Yilmaz M.D., Bekmezci M., Sen F., High-Efficiency Application of CTS-Co NPs Mimicking Peroxidase Enzyme on TMB(ox). Chemosphere, 292: 133429 (2022).
[25] Biallozor S., Kupniewska A., Conducting Polymers Electrodeposited on Active Metals, Synth. Met., 155: 443-449 (2005).
[26] Shahrokhian S., Naderi L., Ghalkhani M., Modified Glassy Carbon Electrodes Based on Carbon Nanostructures for Ultrasensitive Electrochemical Determination of Furazolidone, Mater. Sci. Eng. C., 61: 842-850 (2016).
[27] Chang G., Shu H., Ji K., Oyama M., Liu X., He Y., Gold Nanoparticles Directly Modified Glassy Carbon Electrode for Non-Enzymatic Detection of Glucose, Appl. Surf. Sci., 288: 524-529 (2014).
[28] Ghoreishi S. M., Behpour M., Saeidinejad F., Electrochemical Determination of Tryptophan, Uric Acid and Ascorbic Acid at a Gold Nanoparticles Modified Carbon Paste Electrode, Anal. Methods, 4: 2447-2453 (2012).
[29] Jandaghi N., Jahani S., Foroughi M. M., Kazemipour M., Ansari M., Cerium-Doped Flower-Shaped ZnO Nano-Crystallites as a Sensing Component for Simultaneous Electrochemical Determination of Epirubicin and Methotrexate, Microchim. Acta, 187: 24 (2019).
[31] Foroughi M. M., Jahani S., Aramesh-Boroujeni Z., Rostaminasab Dolatabad M., Shahbazkhani K., Synthesis of 3D Cubic of Eu3+/Cu2O with Clover-Like Faces Nanostructures and their Application as an Electrochemical Sensor for Determination of Antiretroviral Drug Nevirapine, Ceram. Int., 47: 19727-19736 (2021).
[33] Karimi-Maleh H., Moazampour M., Ahmar H., Beitollahi H., Ensafi A.A., A Sensitive Nanocomposite-Based Electrochemical Sensor for Voltammetric Simultaneous Determination of Isoproterenol, Acetaminophen and Tryptophan, Measurement, 51: 91-99 (2014).
[35] Tilahun Yai F., Shimeles Addisu K., Dereje Y., Gebru G., Simultaneous Electrochemical Determination of Paracetamol and Caffeine using Activated Glassy Carbon Electrode, Anal. Bioanal. Electrochem., 12: 93-106 (2020).
[36] Sunil Kumar Naik T. S., Kumara Swamy B. E., Pre-Treated Glassy Carbon Electrode Sensor for Catechol: A Voltammetric Study, J. Electroanal. Chem., 826: 23-28 (2018).
[38] Hailemichael A., Lebohang H., Voltammetric Determination of Chloramphenicol at Electrochemically Pretreated Glassy Carbon Electrode, Bull. Chem. Soc. Ethiop., 21: 1-12 (2007).
[39] Rana A., Baig N., Saleh T. A., Electrochemically Pretreated Carbon Electrodes and their Electroanalytical Applications – A Review, J. Electroanal. Chem., 833: 313-332 (2019).
[40] Qiao J. X., Luo H. Q., Li N. B., Electrochemical Behavior of Uric Acid and Epinephrine at an Electrochemically Activated Glassy Carbon Electrode, Colloid. Surface B., 62: 31-35 (2008).
[41] Hadi M., Rouhollahi A., Yousefi M., Taidy F., Malekfar R., Electrochemical Characterization of a Pyrolytic Carbon Film Electrode and the Effect of Anodization. Electroanalysis, 18: 787-792 (2006).
[42] Nagaoka T., Fukunaga, T., Yoshino T., Watanabe I., Nakayama T., Okazaki S., Uptake of Ions by Electrochemically Treated Glassy Carbon. Anal. Chem., 60: 2766-2769 (1988).
[43] Abdel-Aziz A.M., Hassan H.H., Badr I.H.A., Glassy Carbon Electrode Electromodification in the Presence of Organic Monomers: Electropolymerization versus Activation, Anal. Chem., 92: 7947-7954 (2020).
[44] Allen J. Bard, Faulkner L. R., Electrochemical Methods: Fundamentals and Applications. 2nd ed.; Wiley: 2000.
[45] Chang B.-Y., Park S.-M., Electrochemical Impedance Spectroscopy, Annu. Rev. Anal. Chem., 3: 207-229 (2010).
[47] Frith K.A., Limson J.L., pH tuning of Nafion® for Selective Detection of Tryptophan, Electrochim. Acta, 54: 3600-3605 (2009).
[49] Kemmegne-Mbouguen J. C., Angnes L., Mouafo-Tchinda E., Ngameni E., Electrochemical Determination of Uric Acid, Dopamine and Tryptophan at Zinc Hexacyanoferrate Clay Modified Electrode. Electroanalysis, 27: 2387-2398 (2015).
[50] Safavi  A., Momeni S., Electrocatalytic Oxidation of Tryptophan at Gold Nanoparticle-Modified Carbon Ionic Liquid Electrode, Electroanalysis, 22: 2848-2855 (2010).
[53] Liu J., Dong S., He Q., Yang S., Xie M., Deng P., Xia, Y., Li G., Facile Preparation of Fe3O4/C Nanocomposite and Its Application for Cost-Effective and Sensitive Detection of Tryptophan, Biomolecules, 9: 245 (2019).