1. Development of a surface plasmon resonance based immunosensor for diclofenac quantification in water.
- Author
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Herrera-Domínguez, Marcela, Lambert, Alexander S., Morales-Luna, Gesuri, Pisano, Eduardo, Aguilar-Hernandez, Iris, Mahlknecht, Jürgen, Cheng, Quan, and Ornelas-Soto, Nancy
- Subjects
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SURFACE plasmon resonance , *DICLOFENAC , *CARRIER proteins , *BOLTZMANN'S equation , *SERUM albumin , *ENVIRONMENTAL sampling - Abstract
A Surface Plasmon Resonance (SPR) biosensor based on an inhibition immunoassay was developed for the detection of diclofenac (DCF) in aqueous solution. Due to the small size of DCF, an hapten-protein conjugate was produced by coupling DCF to bovine serum albumin (BSA). DCF-BSA conjugate formation was confirmed via MALDI-TOF mass spectrometry. The resulting conjugate was immobilized onto the surface of a sensor fabricated via e-beam deposition of a 2 nm chromium adhesion layer followed by a 50 nm gold layer onto precleaned BK7 glass slides. Immobilization onto the nano thin gold surface was accomplished by covalent amide linkage through a self-assembled monolayer. Samples were composed of a mixture of antibody at a fixed concentration and DCF at different known concentrations in deionized water, causing the inhibition of anti -DCF on the sensor. The DCF-BSA was obtained with a ratio of 3 DCF molecules per BSA. A calibration curve was performed using concentrations between 2 and 32 μg L−1. The curve was fitted using the Boltzmann equation, reaching a limit of detection (LOD) of 3.15 μg L−1 and limit of quantification (LOQ) of 10.52 μg L−1, the inter-day precision was calculated and an RSD value of 1.96% was obtained; and analysis time of 10 min. The developed biosensor is a preliminary approach to the detection of DCF in environmental water samples, and the first SPR biosensor developed for DCF detection using a hapten-protein conjugate. [Display omitted] • An SPR immunosensor was developed to detect diclofenac in water samples. • The configuration of the immunosensor involves the conjugation of diclofenac and BSA as a carrier protein. • This is the first SPR immunosensor for diclofenac that uses the target analyte conjugated to a protein. • The obtained results are comparable with the only other work published for diclofenac detection using SPR. • The development of this kind of biosensors could help to star regulating the discharge of diclofenac in water. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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