Fluorometric Determination of Alkaline Phosphatase Activity in Food Using Magnetoliposomes as On-flow Microcontainer Devices

• Published in: Journal of agricultural and food chemistry Vol. 62; no. 8; pp. 1819 - 1825
• Main Authors: Román-Pizarro, Vanessa, Fernández-Romero, Juan Manuel, Gómez-Hens, Agustina
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26-02-2014; American Chemical Society, Books and Journals Division
• Subjects: alkaline phosphatase; Alkaline Phosphatase - chemistry; Alkaline Phosphatase - isolation & purification; Animals; detection limit; Flow Injection Analysis - instrumentation; Flow Injection Analysis - methods; fluorometry; Fluorometry - instrumentation; Fluorometry - methods; Gold - chemistry; Metal Nanoparticles - chemistry; milk; Milk - chemistry; Milk - enzymology; Milk Proteins - chemistry; Milk Proteins - isolation & purification; nanogold; temperature; magnetic gold nanoparticle liposome hybrids; alkaline phosphatase activity; on-flow microcontainers; food analysis; flow injection; fluorometric detection
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf5004804

Liposomes containing magnetic gold nanoparticles (AuNPs) and an enzymatic substrate (4-methylumbelliferyl-phosphate) have been used as on-flow microcontainers for reagent preconcentration in a flow injection method for the determination of alkaline phosphatase (ALP) activity. The dynamic range of the calibration graph was 6.4 × 10–3–0.25 U L–1 ALP, and the detection limit was 1.9 × 10–3 U L–1. The precision, expressed as relative standard deviation (RSD%), was in the range of 0.7–2.4%. The overall method showed a sampling frequency of 10 h–1. The method was applied to the determination of ALP in milk samples with recovery values ranging between 87.5 and 104.6%. The residual ALP activity in milk samples subjected to temperature treatments was also determined. The results obtained in the analysis of all milk samples were compared with those obtained by applying a previously described flow injection method.