A Rapid and Sensitive Aptamer-Based Biosensor for Amnesic Shellfish Toxin Domoic Acid

Abstract

With the incidence of harmful algal blooms (HABs) increasing in recent years, the urgent demand for the detection of domoic acid (DA), an amnesic shellfish toxin mainly produced by red tide algae Pseudonitzschia, has aroused increasing attention. Aptamers, a new molecular recognition element, provide clarity in the monitoring of DA. In this study, aptamers of DA were successfully screened by Capture-SELEX. Through identification and truncation optimization, aptamer C1-d with a high affinity (KD value, 109 nM) and high specificity for DA was obtained. The binding mechanism between DA and the aptamer was explored by molecular docking and molecular dynamics (MD) simulation, revealing the critical sites for DA–aptamer interaction. Meanwhile, a BLI-based aptasensor was constructed by C1-d, which displayed a linear range from 0.625 to 10 μM and a LOD of 13.7 nM. This aptasensor exhibited high specificity, good precision and repeatability, and high recovery rates for real samples; the process of detection could be completed in 7 min. This study is the first to identify and investigate the binding mechanism of DA–aptamer interaction and constructed a BLI-based aptasensor for DA, which lays a theoretical foundation for the detection and prevention of DA.

Aptamer-Based Point-of-Care Devices: Emerging Technologies and Integration of Computational Methods

“…They explored the binding mechanism between DA and the aptamer using a molecular docking calculation and MD simulation. In their study, the time of the process of detection was 7 min [220].…”

Online highly selective recognition of domoic acid by an aptamer@MOFs affinity monolithic column coupled with HPLC for shellfish safety monitoring

“…Based on ref. 34, oligonucleotide aptamer targeting DA (5 ′ -P-C6-ATAGG AGTCA CGACG ACCAG AAAAA TAATT TAAAT TTTCT ACCCA ATGCT TTTCG CATAA TATGT GCGTC TACCT CTTGA-3 ′ , denoted as Apt), and control oligonucleotide (5 ′ -P-C6-AAAAA ACCCC CCTTT TTTGG GGGGT TTTTT AAAAA AAAAA AACCC CCCTT TTTTT TGGGG GGTTT TTTTT AAAAA A-3 ′ , denoted as control ssDNA), were synthesized by Sangon Biotech. Co. (Shanghai, China).…”