Blog 5: Biosensors

 Hey everyone! As I was doing my research for this week’s blog, I came across a fascinating concept in synthetic biology that I thought I would bring up. Imagine being able to program living cells to detect toxins, diseases, or changes in the environment and release signals whenever something’s off. 

In today’s blog, I’ll walk you through what biosensors are, how they work, and why they’re one of the most exciting applications of SynBio today. 

What Is a Biosensor?

A biosensor device uses a biological system to detect something specific. After spotting a chemical or toxin, a biosensor will convert its findings into a signal we can read. 

A Standard Biosensor has Five Main Components:    

• Analyte - the thing you’re trying to detect

• Bioreceptor - a molecule that specifically binds to an analyte. 

• Transducer - a tool that takes the biological reaction and turns it into a measurable signal

• Electronics - a tool that processes the signal and makes it readable 

• Display - the final output

Once they’re put together, scientists can use DNA sequences and engineered cells to program these micro-devices to detect anything. 

How Biosensors Work in Synthetic Biology

Now that you know what a biosensor is, let me take it a step further and explain how they work in SynBio. To start, a sensor component inside a cell spots the target it's been programmed to detect. After that happens, the biosensor starts a chain reaction in the cell, which gets read by the genetic log system. This system will trigger a response through a reporter gene to produce something that can be easily measured. Data can then be collected and analyzed to get the desired results. 

Real-World Applications of Biosensors

The process I talked about above has been applied to solve a wide variety of problems. Using biosensor systems, scientists can treat and detect diseases, conditions, and so much more.

One of the best-known examples is the continuous glucose monitor (CGM) used by people with diabetes. Companies like Dexcom and Abbott have developed wearable biosensors that continuously track a person’s glucose levels. Instead of relying on finger pricks and test strips, patients who use these portable biosensors can track all of the information from their phone. The biosensor in a CGM works using a tiny electrode inserted under the skin. Before the sensor is put in, it is coated with an enzyme called glucose oxidase. This enzyme will react with glucose in the interstitial fluid(fluid between your cells) and produce a small electrical signal, which can be read from the user’s smartphone. 

Another example of biosensors would be back in 2019, where a team at the University of Edinburgh engineered a strain of E. coli that glows when it detects arsenic in drinking water. What’s powerful about this specific biosensor is that it gives a glowing signal when arsenic is present and doesn’t require any special equipment to interpret the result. This makes it especially useful in remote or low-resource areas where expensive lab tools may not be available. The biosensor here was developed as a low-cost solution for communities like Bangladesh and West Bengal, where arsenic contamination is a huge health issue. 

Not to mention, in the biotech industry, companies like Synlogic are beginning to develop biosensors that go beyond detection and form the basis of living medicines… but I’ll get into that some other time. These examples are only a handful of the innovations and impacts biosensors have made, but I hope you get the idea that they have a hand in everything. 

Conclusion: 

That’s all for this week’s blog. To recap, biosensors are one of the most exciting ways SynBio is being used to solve real-world problems. 

Moving forward, I’ll dive into SynBio innovations like gene circuits, chassis organisms, and more. Thanks!

– Aidan Kincaid

Resources I used:

https://pmc.ncbi.nlm.nih.gov/articles/PMC4986445/

https://biology.ed.ac.uk/news-events/news-2019/smartphone-based-biosensor-to-tackle-arsenic-poiso