Efficient reaction based colorimetric probe for sensitive detection, quantification, and on-site analysis of nitrite ions in natural water resources.

We have developed a novel aza-BODIPY probe for the sensitive colorimetric detection of the nitrite ions in the aqueous medium by a simple and direct method. This probe selectively recognizes the nitrite ions through a distinct visual color change from bright blue to intense green with a sensitivity of 20 ppb. Uniquely, this probe can be coated on a glass surface to fabricate a simple solid-state dipstick device that can be used for the visual detection of the nitrite ions in the presence of other competing anions in distilled as well as natural water resources like a sea, lake, and river. Furthermore, this probe can be used for the sensitive detection of the nitrate ions when coupled to a reduction step. Our results demonstrate that this probe not only can be used for the on-site analysis and quantification but also can replace the conventional spot test carried out for the nitrite ions in the laboratory practical experiments.