Investigation of the matrix effects on structural stability and application performance of aptamers: Insights from...

In practical applications, the highly-concerned issue regarding food matrix effects on the structure and performance of aptamers has not been systematically investigated. This study first elucidated it by employing a model system for detecting tetrodotoxin in typical seafood. The matrix interference on aptamer A36 was attributed to the aptamers' impaired stability. And the formed A36-protein complexes blocked A36-tetrodotoxin binding sites. Further analysis of structure and affinity of AI-52 with stable structure revealed that it possessed higher anti-matrix interference than A36. Moreover, higher detection limits were observed in typical seafood matrix than binding buffer, with increases of 2.8 to 29.7-fold for A36-based sensor and 2.3 to 6.6-fold for AI-52-based sensor. This work elucidates the mechanism of seafood matrix interference on aptamer and reported for the first time that stable structure of aptamer was very important in enhancing aptamer detection performance, which was due to low nonspecific interaction with protein in matrix.