Biocompatible Random Lasers for Biosensing

Biocompatible lasers suitable for living tissue integration have begun to captivate the scientific community due to their potential to harness the amplifying power of stimulated emission for bio-sensing and cell tracking [1].... [ view full abstract ]

Biocompatible lasers suitable for living tissue integration have begun to captivate the scientific community due to their potential to harness the amplifying power of stimulated emission for bio-sensing and cell tracking [1]. We report a biocompatible self-assembled random laser, made of natural degradable biopolymers such as silk [2].

The biocompatibility, allied with their favorable optical properties and ease of biological functionalisation allows nanostructuring, integration of dyes and lasing. Nanostructuring promotes light confinement while the gain provides light amplification. The lasing action is independent of the overall shape but instead relies on the device’s internal porosity; it can therefore easily adapt to biological media with the ability to withstand stretching, wetness and heat.

We explore lasing as a mechanism for sensing, demonstrating that bio-random lasing acts as a nonlinear sensor that switches off lasing for high pH values, with a sensitivity ~200 times larger than its fluorescent counterpart [3]. The combination of a natural biopolymer and random lasing offers the opportunity for integration of a laser within living tissue, opening a new path at the interface between nanophotonics and medicine.

References:

[1] Ta, V. D., Caixeiro, S. - Fernandes, F. M., Sapienza, R. Adv. Opt. Mat., 2017, 5, 1601022.

[2] S. Caixeiro, M. Gaio, B. Marelli, F. G. Omenetto, R. Sapienza, Adv. Opt. Mat., 2016, 4, 7, 998-1003.

[3] M. Gaio, S. Caixeiro, B. Marelli, F. G. Omenetto, R. Sapienza, Phys. Rev. Applied 2017, 7, 034005.