Competitive inhibition assay for the detection of progesterone in dairy milk using a fiber optic SPR biosensor

Abstract

Analytical methods that are often used for the quantification of progesterone in bovine milk include immunoassays and chromatographic techniques. Depending on the selected method, the main disadvantages are the cost, time-to-result, labor intensity and usability as an automated at-line device. This paper reports for the first time on a robust and practical method to quantify small molecules, such as progesterone, in complex biological samples using an automated fiber optic surface plasmon resonance (FO-SPR) biosensor. A FO-SPR competitive inhibition assay was developed to determine biologically relevant concentrations of progesterone in bovine milk (1-10 ng/mL), after optimizing the immobilization of progesterone-bovine serum albumin (P4-BSA) conjugate, the specific detection with anti-progesterone antibody and the signal amplification with goat anti-mouse gold nanoparticles (GAM-Au NPs). The progesterone was detected in a bovine milk sample with minimal sample preparation, namely ½ dilution of the sample. Furthermore, the developed bioassay was benchmarked against a commercially available ELISA, showing excellent agreement (R = 0.95). Therefore, it is concluded that the automated FO-SPR platform can combine the advantages of the different existing methods for quantification of progesterone: sensitivity, accuracy, cost, time-to-result and ease-of-use.

Biomarkers of fitness and welfare in dairy animals: healthy living

“…Stress cannot be measured with a single biomarker but requires the use of a combination of physiological and behavioral indicators. The hypothesis of non-invasively monitoring HPA axis activation at the farm level has not been tested so far, although the development of technologies for measuring cortisol in milk may not be a limitation (Daems et al ., 2017). Milk cortisol concentrations can change as a result of several genetic and environmental factors (Sgorlon et al ., 2015; Pošćić et al ., 2017), which require more thorough analysis and mathematical modeling before this biomarker could be exploited in the field.…”

Cytokeratins Biosensing Using Tilted Fiber Gratings

“…SPR consists of oscillations of electrons at the interface between positive and negative permittivity materials that are excited by incident light. These oscillations are sensitive to surface adsorption onto the metallic interface, often made of thin continuous films [ 4 ] or immobilized nanoparticles [ 5 ].…”

Nano-Biosensing Platforms for Detection of Cow’s Milk Allergens: An Overview

“…The surface plasmon resonance (SPR) approach offers distinct benefits such as (i) flexibility and versatility and (ii) rapid, automated, and real-time analysis of diverse molecular interactions ranging from peptide-peptide and protein-protein to protein-cell interactions. Different optical biosensing approaches have been exploited for different applications in clinical, environmental, and food analysis [85][86][87][88][89]. SPR biosensors have also been developed for label-free and sensitive sensing of milk proteins [65,66].…”