Waveguide interrogated optical immunosensor (WIOS) for detection of sulfonamide antibiotics in milk

作者：Adrian Javier; Pasche Stephanie^*; Diserens Jean Marc; Sanchez Baeza Francisco; Gao Hui; Marco M Pilar; Voirin Guy

来源：Biosensors and Bioelectronics, 2009, 24(11): 3340-3346.

DOI：10.1016/j.bios.2009.04.036

• Sulfonamide antibiotics
• Immunoassay
• Label-free optical biosensor
• Milk contamination
• Class-selective antibodies

An immunosensor was developed for the detection of sulfonamide antibiotics in milk. Detection relied on a competitive immunoassay format, using immunoreagents previously developed for the generic detection of sulfonamide antibiotics and evaluated by enzyme-linked immunosorbent assay. The immunoassay was implemented onto a microsystem platform, the wavelength interrogated optical sensing device, which uses the evanescent field to probe changes at the interface of a waveguiding layer, and thus allows sensitive detection of biomolecule adsorption. The immunoreagents were immobilized onto the surface of the waveguide chip, and a fluidic cell allowed flowing analyte and detection solutions above the surface. Sulfapyridine was used as reference sulfonamide and detected with the immunosensor in buffer and ;in milk with a limit of detection (IC(90)) of 0.2 +/- 0.1 mu g L(-1) and 0.5 +/- 0.1 mu g L(-1), respectively. The analysis time was below 30 min, including regeneration of the sensing surface, with minimum sample preparation required. The reproducibility of the detection was better than 10%. A blind assay allowed identifying milk samples that were contaminated with different sulfonamide antibiotics at or above the maximum residue limits established by the European Union for these compounds (100 mu g L(-1)). Thus, the developed immunosensor presents great potential as a generic sensing device for the fast and early detection of food contaminants on the field by non-skilled users.

• 出版日期2009-7-15