Rapid and label-free detection of aflatoxin B1 using a rationally truncated aptamer and via circular dichroism measurement

Abstract

Rationally truncating aptamer enhances sensitivity of an aptamer assay for rapid detection of aflatoxin B1 (AFB1) via circular dichroism measurement.

CRISPR/Cas12a-Assisted Chemiluminescence Sensor for Aflatoxin B1 Detection in Cereal Based on Functional Nucleic Acid and In-Pipet Rolling Circle Amplification

“…In comparison to the pure aptamer, CD 280 nm increased and CD 220 nm decreased when the aptamer binds with AFB 1 , resulting from the alteration of base pair stacking and the helicity of the polynucleotide. 35 Similarly, when the duplex reacts with AFB 1 , an increase in CD 280 nm and a decrease in CD 220 nm were observed, demonstrating that AFB 1 binds to aptamers in the duplex. Subsequently, we used various concentrations of AFB 1 to react with the aptamer− activator duplex, and there was a positive dependence between the released activator and AFB 1 concentration (Figure 2A).…”

“…We also demonstrated the binding of AFB 1 to the aptamer and the release of the activator from the duplex by circular dichroism (CD) (Figure S2 of the Supporting Information). In comparison to the pure aptamer, CD 280 nm increased and CD 220 nm decreased when the aptamer binds with AFB 1 , resulting from the alteration of base pair stacking and the helicity of the polynucleotide . Similarly, when the duplex reacts with AFB 1 , an increase in CD 280 nm and a decrease in CD 220 nm were observed, demonstrating that AFB 1 binds to aptamers in the duplex.…”

“…As shown in Figure 4D, only AFB 1 can cause a significant change in the ΔCL value, while other analogues elicited a negligible change. The excellent selectivity of this sensor for AFB 1 detection is mainly attributed to the aptamer with a high affinity for AFB 1 and comprises a dissociation constant of less than 2.0 × 10 −6 M. 32,35 3.4. Accuracy and Reproducibility of the CRISPR/ Cas12a-Assisted Chemiluminescence Sensor.…”

A biosensor encompassing fusarinine C-magnetic nanoparticles and aptamer-red/green carbon dots for dual-channel fluorescent and RGB discrimination ofCampylobacterandAliarcobacter

“…The sequence of C. jejuni -specific aptamer was described in our previous study [34]. The truncation of C. jejuni -specific and A. butzleri -specific aptamers was performed as described previously [35, 36]. Briefly, DNAMAN was used to predict secondary structure of these aptamers; the predicted binding motif regions from the original aptamers were truncated [36] and individually synthesized.…”

“…The sequence of C. jejuni-specific aptamer was described in our previous study [34]. The truncation of C. jejuni-specific and A. butzleri-specific aptamers was performed as described previously [35,36].…”