**Ways to Reach Lower Detection Limits of Lateral Flow Immunoassays**

Anatoly V. Zherdev and Boris B. Dzantiev

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.76926

### **Abstract**

This chapter considers factors influencing sensitivity of lateral flow immunoassay and modern developments that are focused on reaching lower detection limits. The existing variety of proposed approaches is classified in accordance with the "big five rules" for these assays, including proper sample, receptor, interaction, response, and output. The solutions for rapid extraction of target analytes and preventing negative influence of extractants are considered. Role to antibodies affinity and specificity is characterized. Potential of alternate bioreceptor molecules is discussed. Immunoreactants' compositions, concentrations, and locations on the test strip are characterized as factors determining assay parameters. The existing variety of labels is compared in terms of their optical and alternate registration. Tools to modulate a sequence of analytical reactions and to form aggregates of the detected labels are considered. The discussed approaches are illustrated through developments of test strips for detection of mycotoxins, veterinary drugs, and other analytes.-

**Keywords:** immunochromatography, test strips, nonequilibrium interactions, increasing assay sensitivity, nano-sized labels, signal amplification, digital optical measurements-
