A T7exonuclease‐assisted target recycling amplification with graphene oxide acting as the signal amplifier for fluorescence polarization detection of human immunodeficiency virus (HIV) DNA

Abstract

We report a fluorescence polarization (FP) platform for human immunodeficiency virus (HIV) DNA detection based on T7exonuclease-assisted target recycling amplification with graphene oxide (GO) acting as a FP signal amplifier. In the sensing method, the presence of the target DNA leads to target recycling with the assistance of T7exonuclease, furthermore, the amplification products are absorbed onto the surface of GO, so the all FP values are enhanced by GO. More importantly, this FP sensor exhibits high detection sensitivity; under optimal conditions, the change in FP is linear with the concentration of the target DNA within a concentration range of 50-2000 pmol/L, and the detection limit of this method is as low as 38.6 pmol/L. This FP sensor also exhibits high selectivity, even single-base mismatched DNA can be effectively discriminated from complementary target DNA. Above all, the proposed FP sensor may serve as a general platform for the sensitive assay of disease-related genes.

Recent advances in fluorescence anisotropy/polarization signal amplification

“…79,80 In addition, to further improve the sensitivity of the GO-enhancer FA/FP method, exonuclease and nicking enzymes have been employed to achieve target recycling for signal amplification detection. 81,82…”

Graphene-based analytical lab-on-chip devices for detection of viruses: A review

“…Gong et al 102 used rGO for the fabrication of impedimetric DNA biosensor to detect HIV with a LOD of 3.0 × 10 -13 M. Later on, they modified 103 the detection approach by modifying glassy carbon electrode using rGO-nafion composite film for the detection of HIV gene with a LOD of 2.3 x 10 -14 M. Here stability of graphene coating was enhanced by nafion which increases graphene dispersion. They have also used polyaniline/graphene nanocomposite and dropcasted it onto a glassy carbon electrode for HIV detection 104 and this time the LOD is 1.0 × 10 -16 M. Detection of HIV using fluorescence polarization was achieved by Wang et al 105 employing GO as a signal amplifier and the LODof the fabricated chip was 38.6 pmol/L. Kwon et al 106 used a photolithographic approach to fabricate a scalable and flexible, liquid ion-gated GFET structure and decorated it with close-packed carboxylated polypyrrole nanoparticle arrays to sense the HIV with LOD of 1 pM.…”

Recent progress in nanomaterial-enhanced fluorescence polarization/anisotropy sensors

“…Recently, a number of nanomaterial, such as carbon nanoparticles (CNPs), gold nanoparticals (AuNPs), metal-organic frameworks (MOFs), SiO2 nanoparticals (SiO2 NPs), graphene oxide (GO), quantum dots (QDs), carbon nanotubes (CNTs), 2D transition metal dichalcogenide nanosheets (TMD NSs), MnO2 nanosheets were introduced into FP/FA sensor system, has brought revolutionary effect for greatly improving detection sensitivity and application range of FP/FA, due to its unique structure and extraordinary properties such as simple/controllable synthesis and modification, different sizes, large volumes and masses, chemical compositions and morphologies, excellent optical and chemical properties [26][27][28][29][30][31][40][41][42][43][44]. Table 1 lists various targets of interest, FP/FA enhancer and signal amplification methods, analytical performance, and so on [40][41][42][43][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60].…”

“…In addition, this strategy could be easily extended to other DNA or RNA assay by simply switching the corresponding sequences of nucleic acids substrates. In addition, Zhao et al developed a lot of amplified FP system for the determination of DNA or miRNA based on hybridization chain reaction (HCR) and SiO2 NPs [52], T7 exo-assisted target recycling amplification and GO [53], T7 exo-assisted quadratic recycling amplification and GO [85], dendrite-modified Au NPs [86], T7 exo-assisted dual-cycle signal amplification and PS NP [87], respectively. These amplification strategies are not limited to the particular DNA but are perceived to provide universal platforms for highly sensitive determination of a wide spectrum of nucleic acids.…”