Biosensor-Based Determination of Riboflavin in Milk Samples

Abstract

An assay for quantification of riboflavin (Rf) in milk-based products has been developed using the principle of surface plasmon resonance with on-chip measurement. The quantification was done indirectly by measuring excess of Rf binding protein (RBP) that remains free after complexation with Rf molecules originally present in the sample solution. The chip was modified with covalently immobilized Rf in order to bind the RBP in excess. A chemical modification was performed to introduce a reactive ester group at the N-3 position of the natural Rf to bind amino groups present on the chip surface. Calibration solutions were prepared by mixing a range of Rf standard solutions with an optimized concentration of RBP. The Rf content in the milk-based products was then measured by comparison of the response against the calibration. Results obtained were very close to those from an official HPLC-fluorescence procedure. The limit of quantification was determined to 234 microg/L and the limit of detection to 70 microg/L by an injection volume of 160 microL.

Fabrication of riboflavin electrochemical sensor based on homoadenine single-stranded DNA/molybdenum disulfide–graphene nanocomposite modified gold electrode

“…5B gave the enlarged linear part, and the linear calibration equations and their corresponding parameters for the three electrodes were listed in Table 1. It was found that the correlation coefficients for all calibration models were them, the limit of detection given by the rMoS 2 -graphene/A 32 /Au electrode was well comparable with or superior to those values obtained from other analytical methods [35][36][37]. Derived from the slope of the linear calibration models, the order of the sensitivity for the three electrodes toward riboflavin can be obtained as follows: rMoS 2 -graphene/A 32 /Au electrode (0.83 lA lM À1 ) ) bare Au electrode (0.044 lA lM À1 ) > A 32 /Au electrode (0.015 lA lM À1 ).…”

“…Hence, the sensitive and selective detection of riboflavin is of great importance. At present, various analytical methods [34][35][36][37] including high-performance liquid chromatography, surface plasmon resonance, mass spectrometry, fluorescence, and spectrophotometry, have been established for the detection of this analyte. However, most of the analytical techniques require complicated instrumentation, have relatively high cost, or suffer from poor sensitivity and low selectivity.…”

Biosensors in Vitamin Analysis of Foods

“…It is important, of course, to protect samples from UV light during this preparation. The assay was assessed independently during the AOAC PTM study, being compared directly with the offi cial fl uorimetric method described above; the results are given in Table 4.4 [3,23] .…”

Survey of the year 2004 commercial optical biosensor literature

“…Of the 678 articles that stated which Biacore platform was used, most utilized 2000 and 3000 platforms [222, (33%) and 249 (37%), respectively]. Investigators also reported data obtained from Biacore X (129, 19%) and 1000 (57, 8%), as well as from S51 [273,818,831,843,865], J [223,285,737,745,759], Q [892,905,907,910,913], Bialite [492,726,787,873] and Probe [348] platforms.…”