Related Experiment Video
Updated: Jun 10, 2025
Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction
Published on: October 6, 2022
Dual dye-labeled aptamers for detection of dichlorvos using ratiometric fluorescence resonance energy transfer
Yibing Li1, Tongtong Li1, Jiajia Chang1
1State Key Laboratory of Toxicology and Medical Countermeasures, Laboratory of Toxicant Analysis, Academy of Military Medical Sciences, Beijing, 100850, China.
Background:
Dichlorvos (DDVP) is an efficient and highly toxic organophosphorus pesticide. Considering its effects on human health and ecosystems, pesticide residue and pollution monitoring is of great significance. Traditional methods like chromatography with mass spectrometry are not portable or rapid because they use large instruments and complex pre-processing methods. Compared with other optional on-site detection technologies, like enzymatic and antibody methods, aptamers are advantageous because they are stable, readily modified, and inexpensive. Therefore, screening and developing a specific adapter for DDVP detection is necessary and will be of practical value.
Results:
We screened, modified, and compared two dual-labeled aptamer probes (Cy3-DV55-Cy5 and Cy3-DV65-Cy5). The kinetics studied showed that 5 min was sufficient for the detection reaction. Both aptamers showed selectivity for DDVP but DV55 was superior to DV65. To research the binding stabilities and the mechanism between the aptamers and DDVP, the secondary structures, melting temperatures, fluorescence quenching types, and constants were investigated. Which showed that DV55 was specific for DDVP and showed better binding than DV65. Comparison of the UV absorption and FRET for DV55 and the truncated structures suggested that loop 3 in DV55 might play an important role in the binding of DV55 to DDVP. The Cy3-DV55-Cy5 aptamer had a linear range of 0-100 μM for DDVP detection and the limit of detection was 150 nM. Simulated pesticide residue detection experiments showed that the method was simple, fast, and had acceptable recovery (89.8%-105.2 %).
Significance:
Pesticide detection is important but on-site detection methods are usually not portable or rapid. We developed two dual-labeled aptamer probes that could feasibly be practically applied to rapid on-site DDVP detection of pesticide residues and pollutants. This research provides experimental and theoretical data for the development and design of similar pesticide probes.
