Rapid detection of praziquantel using monoclonal antibody-based ic-ELISA and immunochromatographic strips

Figures & data

Figure 1. Hapten synthesis of PZQ-HS.

Figure 2. LC–MS analysis of PZQ derivatives.

Figure 3. The indirect competitive inhibition non-linear standard curve for praziquantel of 4E9. (a) the variable of methanol content in PBS, (b) the variable of pH in PBS, (c) the variable of ionic strength in PBS, and (d) standard inhibition curve for the ic-ELISA.

Table 1. Recovery of PZQ in mackerel by ic-ELISA and strip assay.

		ic-ELISA			Strip
Sample	Spiked level (ng/g)	Mean^a (ng/mL) ± SD	Recovery (%)	CV (%)
	5	1.484 ± 0.046	89	2.875	± ± ±
mackerel	10	3.196 ± 0.062	96	1.860	± ± ±
	25	7.702 ± 0.164	92	1.968	± ± ±
	50	14.418 ± 0.251	87	1.506	+ + +

^aThe working range of ic-ELISA was 2.4–22.8 ng/mL. The spiked mackerel was diluted three times in the pretreatment; ±: weakly positive: the concentration of PZQ was 1–50 ng/mL; +: positive: the concentration of PZQ was ≥ 50 ng/mL.

Figure 4. Optimisation of different antibodies and coating antigens. Antibody 4E9 and coating 1 were better. 1 = 0 ng/mL, 2 = 50 ng/mL.

Figure 5. Immunochromatography strips. (a) Images of the detection of PZQ in PBS. 1 = 0 ng/mL, 2 = 0.5 ng/mL, 3 = 1 ng/mL, 4 = 2.5 ng/mL, 5 = 5 ng/mL, 6 = 10 ng/mL, 7 = 25 ng/mL. (b) Images of the detection of PZQ in mackerel. 1 = 0 ng/mL, 2 = 1 ng/mL, 3 = 2.5 ng/mL, 4 = 5 ng/mL, 5 = 10 ng/mL, 6 = 25 ng/mL, 7 = 50 ng/mL.