title: Simple and suitable immunosensor for β-lactam antibiotics analysis in real matrixes: milk, serum, urine.
abstract: The anti-penicillin G was conjugated to avidin-peroxidase and biotin to obtain immunogen and competitor which were then used to develop a competitive immunosensor assay for the detection of penicillin G and other β-lactam antibiotics, with Kaff values of the order of 10(8) M(-1). The new immunosensor appears to afford a number of advantages in terms of sensitivity, possibility of "in situ" analysis, but especially of simplicity and lower costs, compared with other existing devices, or different chemical instrumental methods reported in the literature and used for the analysis of β-lactam compounds. Satisfactory results were found in the analysis of real matrixes and good recoveries were obtained by applying the standard addition method to spiked milk, urine, serum and drug samples. The new device uses an amperometric electrode for hydrogen peroxide as transducer, the BSA-penicillin G immobilized on polymeric membrane overlapping the amperometric transducer and the peroxidase enzyme as marker. It proved to be highly sensitive, inexpensive and easily reproducible; LOD was of the order of 10(-11)M. Lastly, the new immunosensor displayed low selectivity versus the entire class of β-lactam antibiotics and higher selectivity toward other classes of non-β-lactam antibiotics.
authors.affiliation: Department of Chemistry, "Sapienza" University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Merola
authors.affiliation: Department of Chemistry, "Sapienza" University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Martini
authors.affiliation: Department of Chemistry, "Sapienza" University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Tomassetti
authors.affiliation: Department of Chemistry, "Sapienza" University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy. Electronic address: luigi.campanella@uniroma1.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Campanella
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry; D010400:Penicillin G / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047090:beta-Lactams / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D010400:Penicillin G
keywords: Competitive assay; Drugs and real biological matrixes analysis; Immunosensor; Penicillin G; β-Lactam antibiotics