Simple and rapid detection of ractopamine in pork with comparison of LSPR and LFIA sensors

Min Ji Lee ^a, Sheik Aliya ^a, Eun-Seon Lee ^c, Tae-Joon Jeon ^a,b,*, Mi-Hwa Oh ^c,**, Yun Suk Huh ^a,b,***

^a Department of Biological Science and Bioengineering, Inha University, Incheon 22212, Republic of Korea

^b Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea

^c National Institute of Animal Science, Rural Development Administration, Wanju 55365, Republic of Korea

This study developed a simple and rapid strategic technique to detect ractopamine (chemical growth-promoting agent) in pork. Two highly sensitive and specific gold nanoparticle-based portable sensors, i.e., localized surface plasmon resonance (LSPR) sensors, and lateral flow immunoassay (LFIA) strips were developed to detect veterinary drug residues in food products, that have detrimental effects on humans. Optimization studies were conducted on several sensor devices to improve sensitivity. Each sensor comprised functionalized gold nanoparticles conjugated with ractopamine antibodies. The LSPR sensor chip achieved excellent detection sensitivity = 1.19 fg/mL and was advantageous for quantitative analysis due to its wide dynamic range. On the other hand, LFIA strips provided visual test confirmation and achieved 2.27 ng/mL detection sensitivity, significantly less sensitive than LSPR. The complementary sensors help overcome each other's shortcomings with both the techniques offering ease of use, affordability and rapid diagnosis. Thus, these sensors can be applied on-site for routine screening of harmful drug residues in pork meat. They also provide useful direction for advanced technologies to enhance assay performance for detecting various other food drug contaminants.

Keywords: Biosensors, Lateral flow immunoassay, Localized surface plasmon resonance, Ractopamine, Veterinary drugs

https://doi.org/10.38212/2224-6614.3410