@article{TIAN2026, 
author = {Haibing TIAN and Yingying SHENG and Mina NAN and Yueqi LIN and Huali XUE and Yang BI},
title = {Effects of pH and Metal Ions on the Interaction between Aptamers and Ochratoxin A Studied by Spectroscopy},
year = {2026},
journal = {Food Science},
volume = {47},
number = {5},
pages = {62-70},
keywords = {aptamer, fluorescence spectroscopy, ochratoxin A, circular dichroism spectroscopy, ultraviolet absorption spectroscopy},
url = {https://www.sciopen.com/article/10.7506/spkx1002-6630-20250924-195},
doi = {10.7506/spkx1002-6630-20250924-195},
abstract = {In this study, ultraviolet (UV) spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular docking were utilized to systematically elucidate the binding mechanism between aptamers and ochratoxin A (OTA) at different solution conditions (pH, metal ions, and Ca2+ concentrations). The results indicated that the optimal pH for aptamer binding to OTA was 6–7. In the presence of Ca2+, the primary binding mode between aptamers and OTA was intercalation. Compared with monovalent metal ions, Ca2+ significantly enhances the stability of aptamer-OTA complexes. In addition, the CD spectra showed that Ca2+ and Mg2+ induced the formation of a hybrid G-quadruplex structure between aptamers and OTA. Molecular docking demonstrated that hydrogen bonds were formed between the aptamer bases DG-5 and DG-27 and OTA, with a dissociation constant (Kd) of 725 nmol/L. In summary, this study provides a systematic analysis of how solution conditions influence the interaction between aptamers and OTA, offering a theoretical basis for advancing the application of aptamers in biosensors.}
}