Table 1.

Sensitivity and reproducibility of the QDs-AuNP FRET biosensor to different concentrations of AuNPs-conjugated target DNA. ∆F₁, ∆F₂ and ∆F₃ are fluorescence signal quenching corresponding to three samples. $\overline{\Delta \mathrm{F}}$ is the average value of fluorescence signal quenching, s is standard deviation and RSD is relative standard deviation, where $\mathrm{s}=\sqrt{\frac{{\displaystyle \sum _{\mathrm{i}=1}^{\mathrm{n}}{(\Delta {\mathrm{F}}_i-\overline{\Delta \mathrm{F}})}^2}}{\mathrm{n}-1}}$ $\mathrm{RSD}=\frac{\mathrm{s}}{\overline{\mathsf{\Delta }\mathrm{F}}}\times 100\%$.

Target DNA	∆F (a.u.)			$\overline{\mathbf{\Delta }\mathbf{F}}$ (a.u.)	s (a.u.)	RSD	$\overline{\mathbf{\Delta }\mathbf{F}}$ ± s (a.u.)
	∆F1	∆F2	∆F3
Complementary DNA (0.25 μM)	45.8	47.9	49.3	47.4	1.8	3.8%	47.4 ± 1.8
Complementary DNA (0.5 μM)	70.0	77.3	69.4	72.2	4.4	6.0%	72.2 ± 4.4
Complementary DNA (1.0 μM)	103.0	101.9	106.6	103.8	2.5	2.4%	103.8 ± 2.5
Complementary DNA (2.0 μM)	148.9	168.8	171.9	163.2	12.5	7.7%	163.2 ± 12.5
Complementary DNA (4.0 μM)	201.1	211.0	200.9	204.3	5.8	2.8%	204.3 ± 5.8
Complementary DNA (6.0 μM)	253.2	246.7	255.0	251.6	4.4	1.7%	251.6 ± 4.4
Complementary DNA (8.0 μM)	347.8	353.1	346.1	349.0	3.7	1.1%	349.0 ± 3.7
Complementary DNA (10.0 μM)	409.9	410.5	415.3	411.9	3.0	0.7%	411.9 ± 3.0