Matched loss and high-intensity near-field are critical for plasmonic nanoantennas to achieve ultrasensitive molecular detection. However, the increment in losses during the loss-matching process weakens the intensity of the near-field due to the dissipation of the radiated field. Herein, we develop a multi-hotspot (up to 6) strategy by coupling dark-mode antennas to bright-mode antennas to, for the first time, achieve loss matching while keeping high-intensity near-field simultaneously, which provides ultrasensitive optical elements for molecular detection. Furthermore, amino groups are introduced into metal-organic frameworks (MOFs) through post-synthetic modification to expand the chemisorption function of the MOFs while maintaining their structural integrity for physisorption. Augmented by the physi-chemisorption of MOF-polymer films, our hybrid platform achieves sub-ppm level gas detection. This work provides a new methodology for nanoantenna design and ultrasensitive infrared spectroscopy.