Using 3D laser printing from leaves to create sustainable biosensors

Using an innovative 3D laser printing approach, researchers from Brazil have developed a sustainable method for producing biosensors from foliage. An interdisciplinary team led by Bruno Janegitz from the Universidade Federal de São Carlos and Thiago Paixão from the Universidade de São Paulo presented the results in the journal ACS Sustainable Chemistry & Engineering.

The core idea is to use fallen leaves as a cost-effective substrate for the 3D printing of conductive electrode structures using CO2 lasers. Targeted pyrolysis and carbonization of the leaf fibres creates graphite-reinforced surface patterns that can serve as sensors for electrochemical analyses.

The researchers demonstrated the functionality of the leaf sensors using the example of dopamine and paracetamol detection. One advantage of additive 3D laser manufacturing is that the electrode layouts can be freely designed for different applications.

“By systematically adjusting the laser parameters such as power, scan rate and line density, we can set the surface properties and conductivity for optimum sensor characteristics,” explains Janegitz. For example, the sheet sensors for dopamine achieved a linear measuring range of 10 to 1200 µmol/L and a detection limit of 1.1 µmol/L.

In addition to the impressive analytical performance, the novel 3D printing approach offers advantages in terms of sustainability and cost efficiency. Instead of relying on expensive, resource-intensive carrier materials, biowaste is recycled as recyclable material for sensor production.

Details can be found in the paper “Green Fabrication and Analytical Application of Disposable Carbon Electrodes Made from Fallen Tree Leaves Using a CO2 Laser“.