Overall detection efficiency of Sn samples prepared by different methods.

Sample no.	1 μg Sn	2 μg Sn	2 μg Sn with sandwich structure	4 μg Sn	4 μg Sn with sandwich structure
1	7.40 × 10−4	4.97 × 10−4	2.4 × 10−4	6.33 × 10−5	3.76 × 10−4
2	4.7 × 10−4	3.05 × 10−4	3.1 × 10−4	1.52 × 10−4	7.83 × 10−4
3	3.0 × 10−4	2.98 × 10−4	2.34 × 10−4	8.90 × 10−5	5.96 × 10−4
4	2.8 × 10−4	2.30 × 10−4	1.18 × 10−4	2.37 × 10−5	5.81 × 10−5
5	2.3 × 10−4	1.55 × 10−4	1.73 × 10−4	2.58 × 10−5	3.87 × 10−4
6	2.8 × 10−4	2.3 × 10−4	2.11 × 10−4	6.10 × 10−5	1.42 × 10−4
7	2.4 × 10−4	2.8 × 10−4	1.47 × 10−4	2.69 × 10−5	5.40 × 10−5
8	—	9.5 × 10−5	1.92 × 10−4	—	—
9	—	1.6 × 10−4	1.58 × 10−4	—	—
10	—	1.8 × 10−4	1.27 × 10−4	—	—
Average values	3.63 × 10−4	2.43 × 10−4	1.91 × 10−4	6.31 × 10−5	3.42 × 10−4
RSD/%	50.8	46.9	31.0	73.3	81.4