Are gold nanoparticles the next generation of implantable sensors?

Scientists have developed an implantable sensor using gold nanoparticles, which can work in the human body for “several months” to signal changes in health.

Scientists at Johannes Gutenberg University in Mainz (JGU) have been working on a new implantable sensor, which would be used to signal changes in drug concentration by changing color.

“Our sensor is like an invisible tattoo, not much bigger than a penny and thinner than a millimeter,” said Professor Carsten Soennichsen, head of the nanobiotechnology group at JGU.

First of all, what is an implantable sensor?

While implantable sensors are often viewed with suspicion by the internet, they are actually something very different.

In medicine, implantable sensors constantly transmit information about vital values ​​and concentrations of substances or drugs in the body.

Implantable sensors offer healthcare professionals a way to monitor disease progression and the effectiveness of treatments. Unfortunately, normal implantable sensors have to be replaced after a few days or weeks, which means that the new discovery of a few months could completely change how the sensors work.

Second, why use gold nanoparticles?

Gold nanoparticles act like small antennas for light: they absorb and scatter it strongly and, therefore, appear colored. They react to alterations in their environment by changing colors, which led the research team to decide to exploit this trait for the benefit of implantable sensors.

“We are used to colored objects that turn white over time. Gold nanoparticles, however, do not whiten but retain their color permanently. As they can be easily coated with a variety of different receptors, they provide an ideal platform for implantable sensors, ”said Dr. Katharina Kaefer, lead author of the study.

In the future, implantable sensors based on gold nanoparticles could be used to simultaneously observe the concentrations of different biomarkers or drugs in the body. Such sensors could find application in drug development, medical research, or personalized medicine, such as chronic disease management.

Third, how did scientists stop the body from rejecting the sensor?

To prevent the tiny particles from swimming around or being broken down by immune cells, they are embedded in a porous hydrogel.

Once implanted under the skin, small blood vessels and cells grow in the pores. This means that the sensor is embedded in the tissue and is not rejected as a foreign body.

Since gold nanoparticles are infrared, they are not actually visible to the human eye. However, a special type of measuring device can detect their color non-invasively through the skin.

Finally, what could this mean for medicine?

An implantable gold nanoparticle sensor could be used in various fields – in the treatment of cancer or in the observation of viruses.

This could now be used to observe the concentrations of different biomarkers or drugs in the body at the same time. Such sensors could find application in drug development, medical research or personalized medicine.

When it comes to chronic disease, neuromodulation is already an experimental form of treatment for severe depression. This new sensor could create equally innovative possibilities.

Read the full study here.