Paper-based enzymatic platform coupled to screen printed graphene-modified electrode for the fast neonatal screening
Cristian M Moreira1, Sirley V Pereira1, Julio Raba1
1INQUISAL, Departamento de Química, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Chacabuco 917, D5700BWS San Luis, Argentina.
Introduction:
The PKU is an inborn error of amino acid metabolism, in which phenylalanine (Phe) accumulated in the blood causing alterations at the central nervous system. We report a novel paper-based enzymatic platform coupled to screen printed graphene-modified electrode for the neonatal screening of phenylketonuria (PKU0.
Methods:
The paper-based analytical device coupled to electrochemical detection (EPAD) is based on the use of paper microzones modified with phenylalanine dehydrogenase enzyme (PheDH). The modified PADs were placed on the surface of an electrode modified with electrochemically reduced graphene (ERGO). PheDH in the presence of NAD+ catalyzes the reversible deamination of Phe to form phenylpyruvate, ammonia, and NADH. The electrochemical oxidation of NADH was monitored by differential pulse amperometry (DPA) at 0.6 V. The method was linear in the concentration range from 1 to 600 μmol/L of Phe with a LOQ of 1 μmol/L and LOD of 0.2 μmol/L. Within day precision was 5.7% across 3 levels of control samples. Between-day precision was 8.3%. The comparison with the standard Phe enzyme assay kit showed good agreement. The time required for the overall assay was <5 min. The non-sophisticated equipment required, the short assay time and the appropriate LOQ and LOD achieved by our EPAD make it an attractive and easy to use alternative compared to existing methods applied to the screening of PKU in neonatal samples.
Related Concept Videos
02:46Genetic Screens
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which...
03:02Standard Electrode Potentials
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
01:21G-protein Coupled Receptors
01:17Spin–Spin Coupling: One-Bond Coupling