An ultrasensitive aptasensor for detection of Ochratoxin A based on shielding effect-induced inhibition of fluorescence resonance energy transfer

Sensitive colorimetric detection of ochratoxin A by a dual-functional Au/Fe3O4 nanohybrid-based aptasensor

“…The sequence of OTA aptamer was 5′-GAT CGG GTG TGG GTGGCG TAA AGG GAG CAT CGG ACA-3′ 32 and the sequence of its partially complementary oligonucleotide was 5′-SH-TGTCCG ATG CTC CCT TTA-C6-biotin-3′ (biotin-cDNA-SH). Both of them were chemically synthesized and purified by Sangon Biotech Co. Ltd. (Shanghai, China).…”

Nano-Aptasensing in Mycotoxin Analysis: Recent Updates and Progress

“…The use of gold nanoparticles is also exploited for Förster resonance energy transfer (FRET)-based aptasensors. Gold nanoparticle based fluorescence aptasensors have been employed to detect mycotoxins such as Ochratoxin A [ 56 ], and Aflatoxins [ 57 ] based on different mechanisms. Mainly, nanoparticle has been employed to mediate the quenching of fluorescent dyes, increasing the sensitivity and efficiency of the assays.…”

“…As compared to the assays described above, this aptasensor showed a high sensitivity (LOD = 1.4 ng/L) with a good applicability in spiked wheat and green coffee bean extractives. This may return to the fact that the aptamer was used without any conjugation resulting in a free folding and enhanced affinity to the target [ 56 ] ( Figure 3 ). In another report, AuNPs have been used as quencher to silica nanoparticles coated with streptavidin (used as fluorescence enhancers) to construct a fluorescent aptasensor for OTA detection in grape juice and serum samples.…”

QD-aptamer as a donor for a FRET-based chemosensor and evaluation of affinity between acetamiprid and its aptamer

“…The resonance energy transfer mechanism of FRET and/or surface energy transfer could be responsible for quenching of the donor in the presence of acceptor. 20 Since the distance of 4.815 nm is shorter than 10 nm, the quenching of QD-C-aptamer uorescence is mainly attributable to the FRET mechanism.…”

“…19 A sensor composed of a free aptamer, a gold nanoparticle coated with biotinylated partially complementary DNA, and Cy3-conjugated streptavidin was assembled to detect ochratoxin A based on shielding effect-induced inhibition of FRET. 20 An aptamer-based strategy was presented using multicolour dyes as donors and carbon nanoparticles as acceptors in FRET for the simultaneous detection of V. parahaemolyticus, S. aureus, and S. typhimurium with their corresponding aptamers. 21,22 Hu and co-workers 14 developed an aptamer-based upconversion nanosensor with FRET between a Yb and Ho codoped upconversion material and gold nanoparticles to quantify acetamiprid.…”