A dual mode 'turn-on' fluorescence-Raman (SERS) response probe based on a 1H-pyrrol-3(2H)-one scaffold for monitoring H2S levels in biological samples

Discovery of the biological signaling roles of H2S has spurred great interest in developing reliable methods for its accurate detection and quantification. As considerable variation in its levels is seen during pathological conditions such as sepsis, real-time quantification methods have relevance in diagnosis as well. Of various approaches, reaction-based probes which respond through 'off-on' fluorescence emission remain the most studied. Since the intensity of emission is related to the analyte concentration in these measurements, the presence of built-in features which provide an opportunity for internal referencing will be advantageous. In view of this, a dual mode response system that senses H2S through characteristic fluorescence and Raman (SERS) signals based on a 1H-pyrrol-3(2H)-one scaffold was developed and is the main highlight of this report. This probe offers several advantages such as fast response (<1 min), and high selectivity and sensitivity with a detection limit of similar to 7 nM. Imaging of H2S in HepG2 cells, making use of the SERS signal from the thiolysis product is also demonstrated.

Automated summary

The discovery of the biological signaling roles of H2S has sparked interest in the development of reliable methods for its detection and quantification. Reaction-based probes that respond through 'off-on' fluorescence emission remain the most studied approach. A dual mode response system based on a 1H-pyrrol-3(2H)-one scaffold, which senses H2S through characteristic fluorescence and Raman (SERS) signals, was developed with advantages of fast response and high selectivity and sensitivity. The imaging of H2S in HepG2 cells using the SERS signal from the thiolysis product was also demonstrated.