Engineering constructed of high selectivity dexamethasone aptamer based on truncation and mutation technology

Abstract

Various biosensors based on aptamers are currently the most popular rapid detection approaches, but the performance of these sensors is closely related to the affinity of aptamers. In this work, a strategy for constructed high-affinity aptamer was proposed. By truncating the bases flanking the 59 nt dexamethasones (DEX) original aptamer sequence to improve the sensitivity of the aptamer to DEX, and then base mutation was introduced to further improve the sensitivity and selectivity of aptamers. Finally, the 33 nt aptamer Apt-M13 with G-quadruplex structures was obtained. The dissociation constant (Kd) was determined to be 200 nM by Graphene oxide (GO)-based fluorometry. As-prepared Apt-M13 was used for a label-free colorimetric aptamer sensor based on gold nanoparticles, the LOD was 3.2-fold lower than the original aptamer described in previous works. The anti-interference ability of DEX analogs is also further improved. It indicates that truncation technology effectively improves the specificity of the aptamer to DEX in this work, and the introduction of mutation further improves the affinity and selectivity of the aptamer to DEX. Therefore, the proposed aptamer optimization method is also expected to become a general strategy for various aptamer sequences.

High-Density Au Anchored to Ti3C2-Based Colorimetric-Fluorescence Dual-Mode Lateral Flow Immunoassay for All-Domain-Enhanced Performance and Signal Intercalibration

“…The results showed that hydrocortisone, cortisone, prednisone, prednisolone, and betamethasone exhibited a CR of 23.8, 0.9, 43.1, 41.0, and 92.5%, respectively, whereas progesterone and hydroxy progesterone caproate showed no CR with DXMS (Figure S3A, Table S1). These results were similar to the previous study . The presence of different CRs might stem from the different structural similarities between these structural analogues and DXMS (Table S1), leading to differences in the structure of the Ag recognition site.…”

“…These results were similar to the previous study. 33 The presence of different CRs might stem from the different structural similarities between these structural analogues and DXMS (Table S1), leading to differences in the structure of the Ag recognition site. Overall, the method has a broad spectrum of detection and can simultaneously detect five glucocorticoid drugs.…”

Detection of Cadmium(II) in Aquatic Products Using a Rolling-Circle Amplification-Coupled Ratio Fluorescent Probe Based on an Aptamer–Peptide Conjugate

“…Modulation of the affinity between an aptamer and target is usually achieved by direct mutation of the nucleic acid sequence, including base substitutions, truncation of the aptamer strand, and so on. − However, the aptamer sequence mutation-based approach is both time-consuming and inefficient. − In contrast, our previous work demonstrated that it is possible to combine the two recognition elements through a strategy of coupling aptamers and peptides to simply and conveniently increase affinity by increasing the binding sites . This strategy involves a simple copper-catalyzed alkyne azide cycloaddition (CuAAC) synthesis technique, which can effectively solve the complex process of peptide and aptamer coupling.…”