A visual test paper based on Pb(ii) metal–organic nanotubes utilized as a H2S sensor with high selectivity and sensitivity

Abstract

The fluorescent Pb(II)–metal–organic nanotube, CD-MONT-2, which possesses a large {Pb₁₄} metallamacrocycle, is synthesized by a modified biphasic liquid–solid–liquid (BLSL) strategy. This strategy takes advantage of solid cyclohexanol to avoid generation of by-products, and is suitable for producing CD-MONT-2 on a large scale. Importantly, water-stable CD-MONT-2 can be easily made into H₂S test papers by coating a solution mixture of sodium carboxymethyl cellulose and CD-MONT-2′ on glass plates, which have the characteristics of high efficiency, rapidity, and visualization based on its fluorescence “turn-off” response. The CD-MONT-2 based visual test papers can be used without pretreatment and possess excellent sensitivity and stability.