Progress in immunoassays for nitrofurans detection

Figures & data

Figure 1. Structures of four kinds of nitrofurans and their metabolites.

Figure 2. Schematic diagram of ic-ELISA and ic-TRFIA for nitrofurans detection.

Figure 3. Schematic diagram of fluorescence polarization immunoassay for nitrofurans detection.

Figure 4. Schematic diagram of the immunochromatographic assay for nitrofurans detection.

Table 1. Comparison of immunoassay of nitrofurans in animal food.

Method		Advantage		Disadvantage
Enzyme-linked immunosorbent assay	Enzyme-linked immunosorbent assay	High specificity, high sensitivity, requires few pieces of equipment and is suitable for batch testing		ELISA entails heterogeneous reactions, and full automation is difficult to realize. It requires manual operation, cannot perform simultaneous detection of multiple components. Long detection time.
Fluorescence immunoassay	Fluorescence polarization immunoassay	High sensitivity, could realize automated high-throughput screening, easy to operate		Not as sensitive as ELISA
	Time-resolved fluoroimmunoassay	High sensitivity, kit reagents are stable		Requires the use of rare and expensive earth elements
Chemiluminescence immunoassay	Direct competitive chemiluminescence enzyme immunoassay	Easy to operate, involves a few steps, the detection time is short		Less sensitive than indirect competitive chemiluminescence enzyme immunoassay
	Indirect competitive chemiluminescence enzyme immunoassay	Higher sensitivity		Relatively cumbersome operation and long detection time
	Magnetic particle chemiluminescence enzyme-linked immunoassay	High degree of automation, simultaneous testing of multiple components possible, high detection efficiency and reliable results		Currently less studied on small molecules such as veterinary drug residues
Immunochromatography	Colloidal gold immunochromatographic assay	Low-cost, easy to operate	Convenient operation, suitable for on-site detection, high sensitivity and short detection time	Low sensitivity, challenging to achieve accurate quantification
	Immuno-functionalized magnetic bead-based multiplex immunochromatographic assay	Higher sensitivity		The brown-colored signal is not as vibrant and high in contrast as the bright red color of colloidal gold, not suitable for high-throughput screening.
	Latex bead immunochromatographic assay	More uniform than colloidal gold, more stable and more comfortable with observing on		It was mostly used for the detection of large molecules in the early days, with fewer studies performed on small molecules.
	Quantum dot immunochromatographic assay	High sensitivity		Quantification is tedious; the operation among individuals varies greatly, challenging to realize automation.
Immunosensor assay	Immunosensor assay	Fast, highly sensitive and selective, easy to realize automation		Requires high-sensitivity biosensor