Beach Water Pollution Brought into the Light

A “chemiluminescent probe” might sound like something to dread during your next medical checkup, but fear not. In fact it’s a new tool in development that San Diego scientists and their colleagues in the United Kingdom believe might make detecting contaminated beach water a whole lot easier and faster.

Ken Browne of Gen-Probe Incorporated, Dimitri Deheyn of Scripps Institution of Oceanography at UC San Diego and colleagues developed a new method for detecting molecules using probes that employ light emitted from chemical reactions, or chemiluminescence.

As described in a research paper the scientists recently published in the Journal of the American Chemical Society, chemiluminescent probes are faster and thousands of times more sensitive than traditional detection methods. Based on their success, Deheyn says they are working to develop the concept into tools for rapid detection of viruses and microbes in a range of environments.

For coastal managers and others charged with testing beach water safety, the advancement could mean an enormous leap in speed and efficiency.

Beach closures due to contamination continue to plague popular coastal destinations. A Sept. 8 regional blackout cut power to San Diego pump facilities, spilling millions of gallons of raw sewage into local waters and placing several beaches off limits.

“The current methodology for detecting beach contamination relies on culturing or signal amplification that takes time, often more than 48 hours,” said Deheyn.

Traditional testing methods include organic fluorescent probes that can provide an inexact picture of their targets, whether bacteria, viruses, or fungi, necessitating verification that can increase time and expense. The new chemiluminescent probes signal only in the presence of their specific targets after a short sequence of simple, automatable steps. The chemical triggering of these probes makes them up to 10,000 times more sensitive than fluorescent probes.

“The process of detecting fecal bacteria or toxic microorganisms can speed up dramatically, thus being almost ‘real-time’ to the decision-making process and avoiding the wait time of sometimes days to determine whether a contamination has occurred in the environment,” said Deheyn.

Beyond beach water, such probes could be useful to industries ranging from agriculture, food handling to pharmaceuticals and health care in the search for new and faster methods of detecting microscopic targets.

In addition to Browne and Deheyn, coauthors of the study include Gamal El-Hiti, Keith Smith, and Ian Weeks of Cardiff University.

The results of the project are partially based upon work supported by the Air Force Office of Scientific Research.

-- Mario C. Aguilera