Integrated Amperometric Affinity Biosensors Using Co2+鈥揟etradentate Nitrilotriacetic Acid Modified Disposable Carbon Electrodes: Application to the Determination of 尾-Lactam Antibiotics

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• 作者：Felipe Conzuelo ; Mar铆a Gamella ; Susana Campuzano ; Paloma Mart铆nez-Ruiz ; Mar铆a Esteban-Torres ; Blanca de las Rivas ; A. Julio Reviejo ; Rosario Mu帽oz ; Jos茅 M. Pingarr贸n
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：March 19, 2013
• 年：2013
• 卷：85
• 期：6
• 页码：3246-3254
• 全文大小：341K
• 年卷期：v.85,no.6(March 19, 2013)
• ISSN：1520-6882

文摘

A novel strategy for the construction of disposable amperometric affinity biosensors is described in this work. The approach uses a recombinant bacterial penicillin binding protein (PBP) tagged by an N-terminal hexahistidine tail which was immobilized onto Co²⁺鈥搕etradentate nitrilotriacetic acid (NTA)-modified screen-printed carbon electrodes (SPCEs). The biosensor was employed for the specific detection and quantification of 尾-lactam antibiotics residues in milk, which was accomplished by means of a direct competitive assay using a tracer with horseradish peroxidase (HRP) for the enzymatic labeling. The amperometric response measured at 鈭?.20 V versus the Ag pseudoreference electrode of the SPCE upon the addition of H₂O₂ in the presence of hydroquinone (HQ) as redox mediator was used as the transduction signal. The developed affinity sensor allowed limits of detection to be obtained in the low part-per-billion level for the antibiotics tested in untreated milk samples. Moreover, the biosensor exhibited a good selectivity against other antibiotics residues frequently detected in milk and dairy products. The analysis time was of approximately 30 min.