A label-free and portable multichannel surface plasmon resonance immunosensor for on site analysis of antibiotics in milk samples.
Techniques for immunosensing like surface plasmon resonance (SPR) may respond to the need for rapid screening methods to improve food safety. This paper describes the development of a novel portable six channel SPR biosensor based on the plasmon of gold diffraction grating surface for simultaneous multianalyte antibiotic detection in milk samples. Representative congeners from three important antibiotic families (FQs: fluoroquinolones, SAs: sulfonamides and CAP: phenicols) were chosen for this study. The chips are covalently biofunctionalized with haptenized proteins by means of a previously formed mixed self assembled monolayer (m-SAM) prepared using two types of mercapto alkyl reagents containing polyethyleneglycol (PEG) units. The samples or standards are mixed with specific polyclonal antibodies and injected into the sensor device. The detectability accomplished is very good (i.e. in buffer, enrofloxacin, 0.30 μg L(-1); sulfapyridine, 0.29 μg L(-1); and chloramphenicol, 0.26 μg L(-1)) and whole milk samples can be analyzed directly without clean-up steps, by just diluting the sample five times with water to remove non-specific interferences caused by the matrix. Although the detectability of CAP regarding the MRPL (minimum required performance limit) is slightly compromised by the dilution, the detectability accomplished by FQs and SAs was far below the maximum residue levels (MRLs) established by the European Union.
Fernández
Fátima
F
Applied Molecular Receptors group, IQAC-CSIC, CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Jordi Girona 18-26, 08034 Barcelona, Spain.
Hegnerová
Kateřina
K
Piliarik
Marek
M
Sanchez-Baeza
Francisco
F
Homola
Jiří
J
Marco
M-Pilar
MP
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002701:Chloramphenicol / Q000032:analysis; D000077422:Enrofloxacin; D004867:Equipment Design; D024841:Fluoroquinolones / Q000032:analysis; D005506:Food Contamination / Q000032:analysis*; D059022:Food Safety; D056656:Lab-On-A-Chip Devices; D008892:Milk / Q000737:chemistry*; D013427:Sulfapyridine / Q000032:analysis; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data
D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D000077422:Enrofloxacin; D002701:Chloramphenicol; D013427:Sulfapyridine