A metallic-nanofinger device for chemical sensing. The device includes a substrate, and a plurality of nanofingers. A nanofinger includes a flexible column, and a metallic cap coupled to an apex of the flexible column. At least the nanofinger and a second nanofinger are to self-arrange into a close-packed configuration with at least one analyte molecule disposed between at least the metallic cap and a second metallic cap of respective nanofinger and second nanofinger. A morphology of the metallic cap is to generate a shifted plasmonic-resonance peak associated with amplified luminescence from the analyte molecule. A coating encapsulating the metallic cap to respond upon exposure to a liquid, and a chemical-sensing chip including the metallic-nanofinger device are also provided.