Photonic lab-on-a-chip (LOC) platforms are the solution for performing portable bio-chemical analysis achieving extreme sensitivity while showing a rapid and easy-to-use operation. The analyte sensors, signal detectors and the light sources that are needed for the analysis can be all integrated on the same chip (See Figure 1).

Figure 1. a) Schematic of a photonic lab-on-chip depicting multiple integrated light emitting waveguides, analyte sensors and signal detectors. Each waveguide is coated by quantum dots of different emission λ. Different photonic structures are shown in the left insets of a) (slot waveguide) and in image b) (design that enlarges interaction with quantum dots).

However, nowadays LOCs still rely on bulk light sources to operate because of the complex integration method of the gain material used for the light emission. This hinders their actual portability and potential for commercial realization. A solution to this problem are the polymeric quantum dots, which are a very promising gain material due to their outstanding photoluminescent properties and easy integration on silicon chip via a simple spin-coating (See Figure 2)..

Figure 2. Schematic showing the integration of the polymeric quantum dots on chip via spin-coating followed by curing with UV light. The zoom in image represents the structure of a polymeric CdSe/ZnS-quantum dot with its correspondent band diagram.

The combination of the polymeric quantum dots with the photonic structures we are currently testing make our designs plausible for large-scale manufacturing and suitable for performing multiplexed bio-chemical analysis on LOC platforms (See Figure 1).

Together with the on-chip light sources, high sensitivity sensors such as ring resonators or photonic crystals and innovative graphene-based detectors will be also explored. Our final goal is to produce a fully portable LOC platform that could be commercialized.

For more information about this research topic, contact Iago R. Diez.