Multi-detection method for five common microalgal toxins based on the use of microspheres coupled to a flow-cytometry system

María Fraga, Natalia Vilariño*, M. Carmen Louzao, Laura P. Rodríguez, Amparo Alfonso, Katrina Campbell, Christopher T. Elliott, Palmer Taylor, Vítor Ramos, Vítor Vasconcelos, Luis M. Botana

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)


Freshwater and brackish microalgal toxins, such as microcystins, cylindrospermopsins, paralytic toxins, anatoxins or other neurotoxins are produced during the overgrowth of certain phytoplankton and benthic cyanobacteria, which includes either prokaryotic or eukaryotic microalgae. Although, further studies are necessary to define the biological role of these toxins, at least some of them are known to be poisonous to humans and wildlife due to their occurrence in these aquatic systems. The World Health Organization (WHO) has established as provisional recommended limit 1 μg of microcystin-LR per liter of drinking water. In this work we present a microsphere-based multi-detection method for five classes of freshwater and brackish toxins: microcystin-LR (MC-LR), cylindrospermopsin (CYN), anatoxin-a (ANA-a), saxitoxin (STX) and domoic acid (DA). Five inhibition assays were developed using different binding proteins and microsphere classes coupled to a flow-cytometry Luminex system. Then, assays were combined in one method for the simultaneous detection of the toxins. The IC50's using this method were 1.9 ± 0.1 μg L−1 MC-LR, 1.3 ± 0.1 μg L−1 CYN, 61 ± 4 μg L−1 ANA-a, 5.4 ± 0.4 μg L−1 STX and 4.9 ± 0.9 μg L−1 DA. Lyophilized cyanobacterial culture samples were extracted using a simple procedure and analyzed by the Luminex method and by UPLC–IT-TOF-MS. Similar quantification was obtained by both methods for all toxins except for ANA-a, whereby the estimated content was lower when using UPLC–IT-TOF-MS. Therefore, this newly developed multiplexed detection method provides a rapid, simple, semi-quantitative screening tool for the simultaneous detection of five environmentally important freshwater and brackish toxins, in buffer and cyanobacterial extracts.

Original languageEnglish
Pages (from-to)57-64
JournalAnalytica Chimica Acta
Early online date21 Aug 2014
Publication statusPublished - 19 Nov 2014


  • Aquatic toxins
  • Flow-cytometry system
  • Microalgal toxins
  • Microsphere-based array
  • Multi-detection
  • Screening method

ASJC Scopus subject areas

  • Environmental Chemistry
  • Spectroscopy
  • Analytical Chemistry
  • Biochemistry


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