Dually Crosslinked Supramolecular Hydrogel for Cancer Biomarker Sensing

Lysophosphatidic
acid (LPA) as the biomarker of early stage ovarian cancer is essentially
difficult to detect due to lack of target spots. A dually crosslinked
supramolecular hydrogel (DCSH) was developed to achieve sensing of
LPA, which acts as a competitive guest molecule triggering the responsive
crosslinking of the DCSH. Through this strategy, the surface plasmon
resonance combined with optical waveguide spectroscopy could be used
to quantitatively detect LPA with a responsive range covering physiological
conditions (in pure form as well as mimicking LPA plasma solution)
with high selectivity and sensitivity. LPA efficiently immerses into
the host molecule β-cyclodextrin (β-CD) up to a 1:2 ratio
by the competitive interaction mechanism, confirmed by one-dimensional
nuclear overhauser effect spectroscopy (1D NOESY), high-resolution
mass spectrometry (HRMS), isothermal titration calorimetry (ITC),
and computational simulation. Our method opens a new strategy to detect
biomarkers without target spots and provides a platform for surface
plasmon resonance (SPR)-based sensors measuring small molecules.