Bacteria drive biochip sensor

Researchers are working to connect living cells to computer chips to gain the best of both worlds. Living cells are terrific sensors, and can also be used to evaluate and emulate biological behavior, while electronics are exemplary at serving up data.

Researchers from Tel Aviv University in Israel have built an electrochemical nano-biochip that detects toxic water.

It could eventually be used to detect pollution and chemical warfare threats, according to the researchers.

The chip connects electronics with genetically-engineered bacteria that respond strongly to environmental stress. The advantage of using bacteria to detect toxicity is the bacteria are non-specific detectors, meaning they will react to any substance that causes them harm.

The researchers' proof-of-concept chip joins the electronics with the bacteria using an electrochemical interface. The bacteria's reaction to the presence of a toxic substance triggers a series of chemical reactions that results in an electrical signal being detected by electrodes on the chip.

The device is portable, relatively inexpensive, handles 100-nanoliter-size water samples, and evaluates water toxicity in about 10 minutes. A nanoliter is one millionth of a milliliter. There are about 5 milliliters to a teaspoon.

The method could be used in practical applications within a year, according to the researchers. The work appeared in the June 8, 2005 issue of Nano Letters (Novel Integrated Electrochemical Nano-Biochip for Toxicity Detection and Water).