A Non-Enzymatic Electrochemical Biosensor for the Detection of Phenylalanine using Bismuth Telluride Nanosheets

Abstract

In newborns, phenylketonuria occurs due to the disruption in the breakdown of Phenylalanine (Phe). Phe is an essential amino acid, which is involved in the biosynthesis of proteins and regulation of neurotransmitter hormones. Deficiency of Phe causes damage to the brain and nervous system, further leading to the development of epileptic seizures. In this aspect, a non-enzymatic electrochemical sensor with bismuth telluride nanosheets (Bi2Te3) was developed for the detection of Phe. The scanning electron microscope image confirmed the layered like structure of solvothermal synthesized Bi2Te3. XPS data indicated the presence of Bi³⁺ and Te²⁻ species, which enhanced the charge transfer during electrochemical oxidation of Phe. This sensor effectively detected Phe in the range from 5 nM - 863 µM, with a detection limit of 3.03 nM and a quantification limit of 9.09 nM. The sensor performance was examined in the presence of spiked Phe in human blood serum samples. The figure of merits of of the surface modified electrode with electrocatalytic efficiency makes it suitable for the real-time detection of Phe.