Gan, A. W., Seah, G. E. K. K., Kwek, L. H., & Goh, S. S. (2023). Ion transfer voltammetry of amino acids with an all‐solid‐state ion‐selective electrode for non‐destructive phenylalanine sensing. Electroanalysis, 35(6). Portico. https://doi.org/10.1002/elan.202200501
Abstract:
Amino acids such as phenylalanine (Phe) are key building blocks of proteins
and other biomolecules. Although recent advancements in electrochemical
sensors have enabled the rapid detection of Phe, these sensors are often destructive
as they irreversibly oxidise Phe. In addition, most of them rely on
biorecognition elements, which suffer from limited stability at ambient conditions
and sensitivity towards environmental fluctuations. Herein, we report
the first example of ion transfer voltammetry of Phe using an all-solid-state
ion-selective electrode (ISE). The reversibility of this technique enables both
the sensor and the Phe sample to be reused. The optimal voltammetric ISE
(VISE) exhibits near Nernstian response (56.8 mv/decade) towards Phe and
selectivity against amino acids of all classes (hydrophobic, hydrophilic and
charged). Voltammetric interrogation of the ISE significantly enhances sensitivity,
linear range, selectivity, and stability as compared to traditional open
circuit potential measurements. Phe levels in a commercial nutritional supplement
and drinking waters were determined to demonstrate the viability of
our sensor in real life applications. This proof-of-concept can be applied to
develop VISEs for other amino acids and biological ions for healthcare and
nutrition sensing.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the Agency of Science, Technology and Research - Career Development Fund (CDF) Grant
Grant Reference no. : C210112021