Immunosensor for trace penicillin G detection in milk based on supported bilayer lipid membrane modified with gold nanoparticles

• Published in: Journal of biotechnology 2015-06, Vol.203, p.97-103
• Main Authors: Li, Han, Xu, Bing, Wang, Danqi, Zhou, Yin, Zhang, Hongling, Xia, Wei, Xu, Shunqing, Li, Yuanyuan
• Format: Article
• Language: English
• Subjects: Animals; Antibodies - immunology; Biosensing Techniques; Biosensor; Biosensors; Cholesterol - chemistry; Dielectric Spectroscopy; Electrodes; Gold; Gold - chemistry; Gold nanoparticles; Immunosensors; Lipid Bilayers - chemistry; Lipids; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Milk; Milk - chemistry; Nanoparticles; Penicillin G; Penicillin G - analysis; Penicillin G - immunology; Phosphatidylcholines - chemistry; Scanning electron microscopy; Supported bilayer lipid membrane
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2015.03.013

In this work, we developed an immunosensor for electrochemical detection of penicillin G at trace level. The biosensor was fabricated by immobilizing anti-penicillin G in a supported bilayer lipid membrane (s-BLM) modified with gold nanoparticles, and the modified electrodes were characterized by the scanning electron microscope (SEM), cyclic voltammetry and electrochemical impedance spectroscopy. The biosensor was able to detect penicillin G with a linear correlation ranging from 3.34×10−3ng/L to 3.34×103ng/L and a detection limit of 2.7×10−4ng/L, much lower than the maximum residue limit (MRL) of penicillin G in milk (4ppb, equal to 4×103ng/L) set out by the European Union. The mean coefficient variation (CV) of the intra-assays and the inter-assays were 5.4% and 7.7%, respectively. In addition, the concentration of penicillin G in milk samples determined by this biosensor was in good agreement with that determined by high performance liquid chromatography (HPLC) assay.