Rapid and Low-Cost Field Detection of Marine Toxins

Abstract

Brevetoxins (PbTx) are a group of marine algal toxic compounds that are produced by the bloom-forming dinoflagellate Karenia brevis. During harmful algal blooms (HAB), brevetoxins can reach concentrations high enough to cause human neurological and gastrointestinal illnesses through inhalation of the airborne toxins or consumption of contaminated shellfish. The timely recognition of this toxin in marine environment is of great importance for public safety, human health, human recreation, marine ecology, and the marine economy. We present the development of a low-cost and easy-to-use electrochemical test for rapid and quantitative detection of brevetoxin species in seawater. Specifically, we utilize an assay to enable measurement of PbTx-2 and PbTx-3 with high specificity while lowering the field detection limits to sub-parts-per-billion (ppb) levels via unique use of disposable electrode chips. Key sensor specifications include PbTx-2 detection limit of 0.25 ppb, a linear range of 0.25 - 50 ppb, and sample-to-result turnaround time of < 5 minutes. The assay also works interference-free; the measured electrochemical signal maintains 90% of its magnitude in seawater in the presence of other aquatic toxins. This versatile field sensor will allow near real-time monitoring of brevetoxin levels in seawater throughout the progression of a red tide bloom. Additionally, our platform technology has the potential to monitor shellfish toxins and could find applications in seafood safety where rapid, accurate, and selective detection of toxins is needed.