Development of transition metal oxide platforms for aptasensing of PSA in cell cultures

• Published in: Analytical and bioanalytical chemistry Vol. 416; no. 28; pp. 6421 - 6435
• Main Authors: Kirlangiç, Irem Aydin, Üner, Göklem, Kara, Pinar, Kirmizibayrak, Petek Ballar, Ertaş, Fatma Nil
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2024; Springer Nature B.V
• Subjects: Analytical Chemistry; Aptamers; Biochemistry; Biomarkers; Biosensors; Carbodiimide; Characterization and Evaluation of Materials; Charge transfer; Chemistry; Chemistry and Materials Science; Electrochemical cells; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Electrostatic properties; Ferrocyanide; Food Science; Iron cyanides; Laboratory Medicine; Manganese; Manganese oxides; Metal oxides; Molecular structure; Monitoring/Environmental Analysis; pH effects; Prostate cancer; Prostate-specific antigen; Research Paper; Spectroscopy; Transition metal oxides; Tumor cell lines; Tumor markers; Vascular endothelial growth factor; Aptasensor; Manganese oxide; EIS; PSA
• ISSN: 1618-2642; 1618-2650; 1618-2650
• DOI: 10.1007/s00216-024-05529-w

In this study, a novel aptasensor based on a transition metal oxide–modified pencil graphite electrode (PGE) was developed for the diagnosis of early-stage prostate cancer (PCa) via monitoring the prostate-specific antigen (PSA), which is the main biomarker for PCa. Single-use PGEs modified with pulsed deposited manganese oxide (MnOx) film were used to attach the amino-terminated aptamer specific to the PSA via carbodiimide chemistry. The designed aptasensor was placed in an electrochemical cell containing ferri/ferrocyanide ions as a redox probe to measure the charge transfer resistances (R
ct
) of the electrode surface by electrochemical impedance spectroscopy (EIS) to follow the response of each modification step. The effect of the medium pH on the ionic structure of the aptamer molecule according to its pI value and, thus, the reversing of the direction of the response (ΔR
ct
) by the pH change was also discussed. The level of PSA secreted from PCa cells was investigated using impedimetric transduction. The specificity of the aptasensor was validated through selectivity studies against non-specific tumor markers like VEGF and different cancer cell lines including breast cancer and androgen-insensitive prostate cancer. The developed system showcases a label-free, fast, specific, and cost-effective approach for PSA detection, highlighting the importance of medium pH and the electrostatic environment on the aptamer’s response. Our work emphasizes the potential for such aptasensors in clinical diagnostics and paves the way for further exploration into using transition metal oxides in biosensing applications.
Graphical Abstract