title: Development of a planar waveguide microarray for the monitoring and early detection of five harmful algal toxins in water and cultures.
abstract: A novel multiplex microarray has been developed for the detection of five groups of harmful algal and cyanobacterial toxins found in marine, brackish, and freshwater environments including domoic acid (DA), okadaic acid (OA, and analogues), saxitoxin (STX, and analogues), cylindrospermopsin (CYN) and microcystins (MC, and analogues). The sensitivity and specificity were determined and feasibility to be used as a screening tool investigated. Results for algal/cyanobacterial cultures (n = 12) and seawater samples (n = 33) were compared to conventional analytical methods, such as high performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Detection limits for the 15 min assay were 0.37, 0.44, 0.05, 0.08, and 0.40 ng/mL for DA, OA, STX, CYN, and MC, respectively. The correlation of data obtained from the microarray compared to conventional analysis for the 12 cultures was r(2) = 0.83. Analysis of seawater samples showed that 82, 82, 70, 82, and 12% of samples were positive (>IC20) compared to 67, 55, 36, 0, and 0% for DA, OA, STX, CYN, and MC, respectively, for conventional analytical methods. The discrepancies in results can be attributed to the enhanced sensitivity and cross-reactivity profiles of the antibodies in the MBio microarray. The feasibility of the microarray as a rapid, easy to use, and highly sensitive screening tool has been illustrated for the five-plex detection of biotoxins. The research demonstrates an early warning screening assay to support national monitoring agencies by providing a faster and more accurate means of identifying and quantifying harmful toxins in water samples.
authors.affiliation: Institute for Global Food Security, School of Biological Sciences, Queen's University , Stranmillis Road, Belfast BT9 5AG, United Kingdom.
authors.forename: Sara E
authors.initials: SE
authors.lastname: McNamee
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Elliott
authors.forename: Brett
authors.initials: B
authors.lastname: Greer
authors.forename: Michael
authors.initials: M
authors.lastname: Lochhead
authors.forename: Katrina
authors.initials: K
authors.lastname: Campbell
mesh_terms: D001681:Biological Assay; D015374:Biosensing Techniques; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D020128:Inhibitory Concentration 50; D057230:Limit of Detection; D046228:Microarray Analysis / Q000379:methods*; D012623:Seawater / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014118:Toxins, Biological / Q000032:analysis*; D014867:Water / Q000737:chemistry*
chemical_list: D014118:Toxins, Biological; D014867:Water