Dual-band in situ molecular spectroscopy using single-sized Al-disk perfect absorbers

In this manuscript, we have demonstrated that the antenna-enhanced infrared vibrational spectroscopy can be a powerful platform for high-sensitivity detection of ultrathin layer of polymer molecules and in situ monitoring of their crosslinking reaction as well as their kinetics of network formation. Our precisely designed dual-band perfect absorber (DPA) made of singles-sized resonator array shows strongly-enhanced nearfield intensity and polarization independence, providing a powerful antenna platform for the bond-selective vibrational sensing.