Chromogenic detection of hydrogen sulfide using squarylium-based chemosensors.

Squarylium-based colorimetric hydrogen sulfide (HS) chemosensors (SQ1, SQ2, and SQ3) were developed, and their detection properties were systematically characterized. SQ1 exhibited rapid and high resolution HS sensing properties through significant color changes detectable by naked-eye with limit of detection as low as 7.2 ppb.