Dip Chip biosensor uses microbes to detect almost any toxic substance, right away

 By Ben Coxworth  May 16, 2012    The Dip Chip biosensor, with a key for scale   Once upon a time, tasters were employed by the well-to-do, in order to check that their food or drink wasn't poisonous. Today, there are electronic biosensors that can do more or less the same thing. Unfortunately, as was no doubt sometimes the case with the tasters, the biosensors can't always give us immediate results. Additionally, they're usually only able to test for specific substances, and not simply for "anything that's toxic." An experimental new device known as the Dip Chip, however, is said to address both of those problems.  The biosensor was created by Professors Yosi Shacham-Diamand and Shimshon Belkin, of Tel Aviv University and the Hebrew University of Jerusalem, respectively.  It contains microbes, which have been genetically modified to produce a biochemical reaction whenever they're exposed to a toxic material, not unlike the reactions that occur in humans and other animals. A dip stick-like tube holds the microbes immobilized, next to the device's sensing electrodes. When that tube is introduced to a substance, the microbes will react accordingly, with any chemical signals released by them being converted into an electrical signal. The device analyzes the output of the electrodes, and delivers a "toxic" or "not toxic" diagnosis.  The Dip Chip reportedly gives very few false readings, either positive or negative. Because it simply senses toxicity in general, it could reportedly be used to detect any kind of poisonous substance – even ones that haven't been heard of yet. It also provides results in real time, so could be invaluable for field use by people such as soldiers or campers.  Shacham-Diamand hopes that the Dip Chip can be miniaturized to the point that it could be used with a smartphone or other mobile device. A larger version of it has already been produced, however, designed for the continuous online monitoring of municipal water supplies.  The technology could conceivably also be used in place of lab animals, for testing the toxicity of newly-developed materials. 

Source: Tel Aviv University