Development of an ic-ELISA and immunochromatographic strip for detection of sparfloxacin in honey

Figures & data

Figure 1. Synthesis of immunogen and coating antigen (Protein: BSA or OVA).

Figure 2. UV scanning of BSA, SPFX-BSA, SPFX (BSA: Bovine serum albumin; SPFX–BSA: The conjugate of SPFX with BSA).

Figure 3. Inhibitive curve of SPFX mAb by ic-ELISA.

Table 1. The CR of SPFX mAb 3D5 with compete compounds.

Compound	IC50(ng/mL)	CR (%)
Sparfloxacin	0.30	100
Flumequine	7.47	4.01
Fleroxacin	88.21	3.40
Enrofloxacin	97.36	3.08
Ciprofloxacin	178.23	1.68
Ractopamine	>3.2 × 10^3	<0.009
Gentamicin	>3.2 × 10^3	<0.009
Terbutaline	>3.2 × 10^3	<0.009
Clenbuterol	>3.2 × 10^3	<0.009
Sabutamol	>3.2 × 10^3	<0.009

Figure 4. Standard curve of SPFX by ic-ELISA.

Figure 5. The spiked sample analysis with lateral-flow ICA strip by visual (n = 6). The spiked sample with SPFX: (A) 0 ng/mL; (B) 0.25 ng/mL; (C) 0.5 ng/mL; (D) 1 ng/mL; (E) 1.25 ng/mL; (F) 1.5 ng/mL; (G) 2 ng/mL; (H) 2.5 ng/mL. Negative result: the test line can be observed. Positive result: no test line is observed.

Table 2. The spiked sample analysis with ic-ELISA and lateral-flow ICA strip (n = 6).

Spiked SPFX (ng/mL)	ic-ELISA		Lateral-flow ICA strip
	Results (ng/mL)	Recovery (%)	Results (visual)
0.8	0.78 ± 0.49	97.5 ± 4.90	−
2	1.87 ± 0.87	93.5 ± 4.35	+
5	5.05 ± 0.62	101.0 ± 3.97	++

Note: −: negative; +: weakly positive; ++: positive.

Table 3. Concentrations of SPFX in honey samples determined by ic-ELISA and HPLC.

Sample (ng/mL)	ic-ELISA (ng/mL)	HPLC (ng/mL)
Sample1, 0.8	0.78 ± 0.49	0.799 ± 0.001
Sample2, 2	1.87 ± 0.87	1.985 ± 0.040
Sample3, 5	5.05 ± 0.62	4.963 ± 0.011