Bacterial Biosensor

Introduction

The disaster in Flint, Michigan has shined a desperately-needed light on America’s aging infrastructure. Lead in Flint’s tap water far exceeded safe levels in a 2014 study. Lead exposure can cause nervous system damage, learning disabilities, shorter stature, impaired hearing, and impaired function of blood cells, especially in children. Many scientist fear this problem may not be isolated to Flint. Across the country, communities need a cheap and reliable method for detecting trace amounts of lead in drinking water.

Cellular engineers have re-engineered bacteria to glow when they detect toxic levels of lead in the drinking water. Using a gene that creates a glowing protein (similar to GFP) when the bacteria absorb lead, cellular engineers have converted these bacteria into biosensors – sensors made from living organisms. These bacterial biosensors could be used as an early warning system, reporting the presence of lead and possibly revealing the lead concentration in each sample without the need for expensive testing equipment.

SIM Background Download Here (png)

SIM Background Download Here (jpeg)

Programming Challenge:

The challenge mat contains three water samples, with varying levels of ‘lead’ (red circles). Program your robot to act as a biosensor and report the sample with the highest lead concentration.

Requirements:

The robot must use ‘lead’ concentration (number of red spots in a given area), not distance, to correctly report dangerous levels of contamination. The red dots will be placed randomly at the time of the challenge, so your robot should be able to scan and count the lead density.

Challenge Mat Materials:

1 challenge mat (see above)

50 red felt circles ("lead contaminants", divided between the three black boxes to present three different concentrations: 5, 15, and 30)

Questions to guide your reading:

What situations might biosensors be useful in?
Advantage of using cells as sensors over machines?
Are there examples of biosensors in use?
How do microbial biosensors work?
What are some of the technologies being proposed to design new biosensors?