A fluorescent aptasensor for the detection of Aflatoxin B1 by graphene oxide mediated quenching and release of fluorescence

Nuclease Triggered “Signal-On” and Amplified Fluorescent Sensing of Fumonisin B1 Incorporating Graphene Oxide and Specific Aptamer

“…To achieve amplified monitoring of FB 1 [ 35 , 36 ], the fluorophore-modified aptamer was dissolved and diluted to 100 nM with Tris buffer. Then, graphene oxide at a concentration of 20 μg mL −1 was incubated with the aptamer solution at room temperature for 15 min to produce an aptamer/GO compound ( Figure 5 ), together with a remarkably reduced fluorescent signal.…”

“…In addition to the fluorescence quenching performance, GO can protect ssDNA aptamers from nuclease digestion because of the hydrophobic stacking reactions between nucleobases and GO [ 32 , 33 , 34 ]. As a consequence, fluorescent aptasensing coupled with GO nanomaterials has been developed to monitor AFM1 and AFB1 in our previous research and another recent attempt, respectively [ 35 , 36 ]. To the best of our knowledge, an aptamer-based sensor combining fluorescence-quenching and aptamer protection of GO with nuclease amplification for detection of FB 1 has not yet been found.…”

Establishment of a Dual-Signal Enhanced Fluorescent Aptasensor for Highly Sensitive Detection of Ochratoxin A

“…1,13 Among various nanomaterials in fabricating the fluorescent aptasensing platform, graphene oxide (GO) with a large twodimensional (2-D) conjugate structure, easily modified surface, good biocompatibility, and excellent dispersibility in water is commonly used as an excellent energy acceptor for effectively quenching the fluorescence of various fluorophores including carboxyfluorescein (FAM) through fluorescence resonance energy transfer (FRET). 10,14 More excitingly, single-stranded DNA (ssDNA) like aptamer can be adsorbed onto the surface of GO through hydrophobic and π−π stacking interactions. 10,15 Then, FAM-labeled aptamer can be assembled on GO to completely quench the fluorescence of FAM, and GO is regarded as an excellent signal enhancer to improve the performance of the developing fluorescent sensing platforms.…”

Target-responsive aptamer-cross-linked hydrogel sensors for the visual quantitative detection of aflatoxin B1 using exonuclease I-Triggered target cyclic amplification

“…To address these issues, in the early 1990s, Ellington and Szostak obtained a nucleic acid sequence after multiple rounds of Systematic Evolution of Ligands by Exponential Enrichment (SELEX), which they named an “aptamer ( Ellington & Szostak, 1990 ).” Aptamers are of interest because can be easily prepared and modified, and they are also known to exhibit a strong thermal stability, low immunogenicity properties, almost no batch-to-batch variation, and facile storage and transportation; as such, they are expected to replace antibodies for various applications ( Ni, et al, 2020 ). In recent years, there have been many reports on the application of aptamers in the detection of mycotoxins, such as in target-responsive DNA smart hydrogel sensors ( Liu et al, 2015 , Sun et al, 2020 ), electrochemical sensors ( Jahangiri-Dehaghani et al, 2022 , Zhong et al, 2022 , Chen et al, 2022 , Zhong et al, 2022 ) ( Jahangiri–Dehaghani, Zare, Shekari, & Benvidi, 2022 ), fluorescence colorimetric sensors ( Setlem et al, 2022 , Zhang et al, 2022 , He et al, 2020 , Qi et al, 2022 ) etc. Among them, target-responsive DNA smart hydrogel sensors have attracted extensive attention owing to their flexibility, stability, cost-effectiveness, portability, and ease of storage, and they are considered to have great prospects for application in the field of on-site detection.…”