Capacitive sensing of microcystin variants of Microcystis aeruginosa using a gold immunoelectrode modified with antibodies, gold nanoparticles and polytyramine

Research output: Contribution to journalArticle


We report on the application of an automated and easy-to-use device to directly measure the immunoreactions between adda-specific monoclonal antibodies and microcystins. The antibodies were immobilized on a gold electrode whose surface was modified first with polytyramine and then with gold nanoparticles. The immunoreaction leads to a change in the capacitance of the system. Under optimum conditions, the sensor is capable of performing stable regeneration-assay cycles and has a low detection limit at a concentration of 0.01 pM level of microcystin-leucine-arginine (MC-LR). The surface of the biosensor can be regenerated with pH 2.5 glycine buffer which dissociates the antibody-antigen complex. The biosensor was used to monitor the production of microcystins during batch cultivation of Microcystis aeruginosa (isolated from ponds in Botswana). Liquid chromatography coupled to MS/MS detection was used to identify three variants, viz. MC-LR (995.6 Da), DmMC-LR (981.2 Da) and MC-LA (910.5 Da).


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Industrial Biotechnology


  • Capacitive biosensor, Microcystins, Adda-specific antibodies, M., aeruginosa, Real-time analysis
Original languageEnglish
Pages (from-to)1009-1017
JournalMikrochimica Acta
Issue number9-10
Publication statusPublished - 2014
Publication categoryResearch