Investigation of thymine as a potential cancer biomarker employing tryptophan with nanomaterials as a biosensor

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 301; p. 122928
• Main Authors: Abou El-Nour, Kholoud M., El-Sherbiny, Ibrahim M., Khairy, Gasser.M., Abbas, Abbas M., Salem, Eman H.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.11.2023
• Subjects: Fluorescence; Gold-silver nanocomposite; Graphene oxide; Nanomaterials; Thymine; Tryptophan; Fluorescence; Tryptophan; Nanomaterials; Graphene oxide; Gold-silver nanocomposite; Thymine
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2023.122928

[Display omitted] •This study is recognized as the first to directly assess thymine (Thy) as a potential cancer biomarker using tryptophan (Trp) and tryptophan-based nanomaterial sensors.•Through the quenching of tryptophan and tryptophan-based nanomaterials, fluorescence in a physiological buffer, thymine was determined.•The tryptophan and tryptophan/nanomaterials method for determining thy has a linear dynamic range of 10 to 200 M and detection limit of 3.21 µM.•The binding constant (Ka) of thymine with trp and trp-based nanomaterials, as well as the enthalpy (H°) and entropy (S°) change values, were evaluated.•A recovery study was carried out using a human serum sample, the results for thymine determination indicate excellent recovery. Tryptophan and tryptophan-based nanomaterials sensors in a solution have been developed to directly evaluate thymine. The determination of thymine has been done via quenching of the fluorescence of tryptophan and tryptophan-based nanomaterials such as graphene (Gr), graphene oxide (GO), gold nanoparticles (AuNPs), gold-silver nanocomposite (Au-Ag NC) in a physiological buffer. As the concentration of thymine rises, the fluorescence of tryptophan and tryptophan/nanomaterials becomes less intense. Trp, Trp/Gr, and tryptophan/(Au-Ag) NC systems' quenching mechanisms were dynamic, but tryptophan /GO and tryptophan/AuNPs' quenching mechanisms were static. The linear dynamic range for the determination of thy by tryptophan and tryptophan /nanomaterials is 10 to 200 μM. The detection limits for tryptophan, tryptophan /Gr, tryptophan /GO, tryptophan /AuNPs, and tryptophan/Au-Ag NC were 3.21, 14.20, 6.35, 4.67and 7.79 Μm, respectively. Thermodynamic parameters for the interaction of the Probes with Thy include the enthalpy (H°) and entropy (S°) change values, were assessed, as well as the binding constant (Ka) of Thy with Trp and Trp-based nanomaterials. A recovery study was conducted utilizing a human serum sample after the addition of the required quantity of the investigational thymine.