Ultrasensitive sulphide detecting by using Au (core)-Ag (shell) triangular nanoprisms

Hydrogen sulfide (H₂S), the third endogenous gaseous molecule, plays a crucial role in biological signaling and metabolic processes. It has garnered significant attention from researchers in the field of biochemistry. The highly sensitive detection of H₂S is essential for elucidating its functions and has long been a key objective in biochemical sensing. In this study, we present an ultrasensitive method for sulfide detection utilizing gold (core)-silver (shell) triangular nanoprisms (Au@Ag TNPs). This strategy is predicated on the preferential formation of Ag₂S at the sharp corners of Au@Ag TNPs, which is manifested as a sensitive spectral shift observed in the nanoprobes. In comparison to the detection limit for sulfide using Au@Ag nanorods, as reported in Nat. Commun.4, 1708 (2013)10.1038/ncomms2722, this detection limit can be enhanced by three orders of magnitude when employing Au@Ag TNPs. Leveraging the single-particle scattering spectrum of individual Au@Ag TNPs, we have successfully reduced the detection limit for sulfide to 1 fM. This represents the lowest reported value for sulfide detection to date. This study presents a highly effective plasmonic nanoprobe for ultrasensitive sulfide detection, which is poised to play a significant role in biochemistry and environmental sciences.