Graphene Surface-Anchored Fluorescence Sensor for Sensitive Detection of MicroRNA Coupled with Enzyme-Free Signal Amplification of Hybridization Chain Reaction

A new enzyme-free signal amplification-based assay for microRNA (miRNA) detection is developed by using hybridization chain reaction (HCR) coupled with a graphene oxide (GO) surface-anchored fluorescence signal readout pathway. MiRNAs can efficiently initiate HCR between two species of fluorescent hairpin probes. After HCR, both of the excess hairpin probes and the HCR products will be anchored on the GO surface. The fluorescence of the hairpin probes can be completely quenched by GO, whereas the HCR products maintain strong fluorescence. Therefore, integrating HCR strategy for signal amplification with selective fluorescence quenching effects of GO provides a versatile miRNA assay

Evaluation standard for rice resistance to planthoppers based on seedling mortality (adapted from Horgan et al. 2015).

<p>Evaluation standard for rice resistance to planthoppers based on seedling mortality (adapted from Horgan et al. 2015).</p

Sex ratio, female weight and longevity (mean ± SE) of <i>Nilaparvata lugens</i> developed on rice germplasms.

<p>A: Sex ratio (n = 3). B: Female weight (n = 30). C: Female longevity (n = 15). The different letters over the bars in a panel indicate significant differences (Tukey HSD, <i>P</i> = 0.05).</p

Developmental duration (A, n = 240) and survival (B, n = 3) (mean ± SE) of <i>Nilaparvata lugens</i> nymphs on rice germplasms.

<p>Different letters over the bars in a panel indicate significant differences (Tukey HSD, <i>P</i> = 0.05).</p

Population size (no./100 hills, mean ± SE) of <i>Nilaparvata lugens</i> in field plots (n = 3) of the TN1, IR64, B5, HHZ, BR4831, 9311, HF106, and C602 rice germplasms.

<p>Population size (no./100 hills, mean ± SE) of <i>Nilaparvata lugens</i> in field plots (n = 3) of the TN1, IR64, B5, HHZ, BR4831, 9311, HF106, and C602 rice germplasms.</p

Population parameters (mean ± SE) of <i>Nilaparvata lugens</i> fed on the TN1, IR64, B5, HHZ, BR4831, 9311, HF106, and C602 rice germplasms.

<p>Population parameters (mean ± SE) of <i>Nilaparvata lugens</i> fed on the TN1, IR64, B5, HHZ, BR4831, 9311, HF106, and C602 rice germplasms.</p

Settling preferences of macropterous female <i>Nilaparvata lugens</i> adults for plants of the rice germplasm at 24 h (A), 72 h (B) and 120 h (C) after insect release in the cage tests.

<p>Data are expressed as the mean ± SE from 10 replicates. Different letters over the bars in a panel indicate significant differences (Tukey HSD, <i>P</i> = 0.05).</p

Resistance to <i>Nilaparvata lugens</i> assessed with the standard seed box test at the seedling stage of rice germplasms.

<p>Data are expressed as the mean ± SE from 10 replicates. Different letters over the bars indicate significant differences (Tukey HSD, <i>P</i> = 0.05).</p

Weight of honeydew (mean ± SE, n = 30) excreted by female <i>Nilaparvata lugens</i> adults on rice germplasms.

<p>Different letters over the bars indicate significant differences (Tukey HSD, <i>P</i> = 0.05).</p

Effects of silicon amendment to rice plants on larval survival rate of <i>Cnaphalocrocis medinalis</i>.

<p>+Si = silicon amendment at 0.32 g Si/kg soil to rice plants,–Si = no silicon amendment. Values are means ± SE from 3 replicates measured with different leaf samples. Different letters over the bars in a certain larval stadium denote significant difference at <i>P</i> < 0.05 according to Independent-samples t-test.</p