The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic
noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the
expansion of the field include the development of alternative and sustainable sensing materials. The discovery
that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to
develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuliresponsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report
the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to
analyses of gas chromatography–mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and Xray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato
suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When
either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive
morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform,
toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid).
The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks.
The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of
each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was
implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based
sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that
such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays
to enlarge selectivity and sensing capacity.

Rapid, real-time, and non-invasive identification of volatile organic compounds (VOCs)
and gases is an increasingly relevant field, with applications in areas such as healthcare, agriculture,
or industry. Ideal characteristics of VOC and gas sensing devices used for artificial olfaction include
portability and affordability, low power consumption, fast response, high selectivity, and sensitivity.
Microfluidics meets all these requirements and allows for in situ operation and small sample amounts,
providing many advantages compared to conventional methods using sophisticated apparatus such
as gas chromatography and mass spectrometry. This review covers the work accomplished so far
regarding microfluidic devices for gas sensing and artificial olfaction. Systems utilizing electrical
and optical transduction, as well as several system designs engineered throughout the years are
summarized, and future perspectives in the field are discussed.