Silver decorated silanized graphene oxide based molecularly surface imprinted electrochemical sensor for the trace level detection of L- Tryptophan

L-Tryptophan (TRP) is a major precursor for neurotransmitter Serotonin, neurohormone Melatonin, Vitamin B3, phytohormone Auxins, Catecholamine Adrenalin, Dopamine, and Melamine. It has some adverse effects like the production of toxic substances in the brain leading to Hallucination Delusion, Schizophrenia, Parkinson's disease, and Alzheimer's disease. The oxidative by-product accumulation also leads to the generation of cancer. Due to its importance as well as toxic effects, there is an increased significance for the accurate determination of TRP. Silver decorated Silanized graphene oxide (Silanized Ag-GO) based molecularly imprinted electrochemical sensor was synthesized and used for the selective and specific detection of TRP. Silyl functionalization was done by using vinyl trimethoxysilane (VTMS). Pre-polymerization mixture was prepared by mixing the template TRP and the monomers such as methacrylic acid (MAA) and styrene in dimethyl sulfoxide (DMSO). The electrochemical properties of the synthesized materials were characterized using Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltam-metry (CV), and Differential Pulse Voltammetry (DPV). Working electrodes were prepared by modifying the Bare Glassy Carbon electrode (Bare GCE) with TRP imprinted polymer (TRP/MIP) and non-imprinted polymer (TRP/ NIP). The surface area of TRP/NIP, TRP/MIP modified Bare GCE electrodes (TRP/NIP/GCE and TRP/MIP/GCE) was calculated as 0.2437, and 0.443 cm2 respectively. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 3.23 x 10-10 M and 10.76 x 10-10 M with a correlation coefficient (R2) value of 0.9958. In addition to this, herein reported electrochemical sensor was successfully used for the detection of TRP in the blood serum sample. This exposes the perspective clinical application of the synthesized electrochemical sensor.