Competitive Upconversion-Linked Immunosorbent Assay for the Sensitive Detection of Diclofenac
Language English Country United States Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
- MeSH
- Water Pollutants, Chemical analysis MeSH
- Diclofenac analysis MeSH
- Immunoassay methods MeSH
- Immunosorbents chemistry MeSH
- Nanoparticles chemistry MeSH
- Silicon Dioxide chemistry MeSH
- Drinking Water chemistry MeSH
- Surface Properties MeSH
- Particle Size MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Water Pollutants, Chemical MeSH
- Diclofenac MeSH
- Immunosorbents MeSH
- Silicon Dioxide MeSH
- Drinking Water MeSH
Photon-upconverting nanoparticles (UCNPs) emit light of shorter wavelength under near-infrared excitation and thus avoid optical background interference. We have exploited this unique photophysical feature to establish a sensitive competitive immunoassay for the detection of the pharmaceutical micropollutant diclofenac (DCF) in water. The so-called upconversion-linked immunosorbent assay (ULISA) was critically dependent on the design of the upconversion luminescent detection label. Silica-coated UCNPs (50 nm in diameter) exposing carboxyl groups on the surface were conjugated to a secondary anti-IgG antibody. We investigated the structure and monodispersity of the nanoconjugates in detail. Using a highly affine anti-DCF primary antibody, the optimized ULISA reached a detection limit of 0.05 ng DCF per mL. This performance came close to a conventional enzyme-linked immunosorbent assay (ELISA) without the need for an enzyme-mediated signal amplification step. The ULISA was further employed for analyzing drinking and surface water samples. The results were consistent with a conventional ELISA as well as liquid chromatography-mass spectrometry (LC-MS).
CEITEC Central European Institute of Technology Masaryk University Brno 625 00 Czech Republic
Institute of Analytical Chemistry AS CR v v i Brno 602 00 Czech Republic
References provided by Crossref.org
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