The selective detection and separation of target ions or molecules is an intriguing issue. Herein, a novel supramolecular organic framework (SOF-THBP) was constructed by bis-thioacetylhydrazine functionalized pillar[5]arenes. The SOF-THBP shows a fluorescent response for Fe , Cr , Hg and Cu ions. The xerogel of SOF-THBP shows excellent recyclable separation properties for these metal ions and the absorption rates were up to 99.29 %. More interestingly, by rationally introducing these metal ions into the SOF-THBP, a series of metal-ion-coordinated SOFs (MSOFs) such as MSOF-Fe, MSOF-Hg and MSOF-Cu were constructed. These metal ions coordinated MSOFs could selectively sense F , Br , and l-Cys, respectively. The detection limits of these MSOFs for F , Br and l-Cys were about 10 m.

By rationally introducing multi-interactions sites, supramolecular polymer networks (SPN-TDPG) has been successfully designed and constructed. SPN-TDPG gel shows aggregation-induced emission, meanwhile, its xerogel possesses a porous sponge structure. Interestingly, the SPN-TDPG shows detection and separation properties for broad-spectrum pollutants, such as heavy metal ions, anions, oxometallates, various organic dyes, organic pollutants, and volatile organic compounds. The detection limits of SPN-TDPG-based gel for cations and anions are in the range of 10–8 to 10–9 M. Moreover, the separation rates of SPN-TDPG-based xerogel for heavy metal ions, oxometallates, various organic dyes, and organic pollutants can reach up to 99.8%. The high sensitivity and broad-spectrum adsorption separation properties are based on the multi-interaction sites that we rationally introduced into the SPN-TDPG. Therefore, it is a convenient way for the preparation of SPN-based spongy multiple functional materials.

The development of novel materials for the detection and removal of Hg is a very important issue due to the acute toxicity of Hg. Herein, a novel supramolecular polymer P5BD-DPHB has been constructed by the collaboration of a naphthalimide functionalized-pillar[5]arene host (P5BD) and a bis-bromohexane functionalized-pillar[5]arene guest (DPHB). P5BD-DPHB could form a stable supramolecular gel (P5BD-DPHB-G). Interestingly, P5BD-DPHB-G shows selective fluorescent "turn-on" detection for Hgvia cation-π interactions with high selectivity and sensitivity. Furthermore, the Hg coordinated supramolecular gel P5BD-DPHB-HgG can detect I successively. The detection limits for Hg and I are 1.65 × 10 and 1.84 × 10 mol L, respectively. Even more significantly, the xerogel of P5BD-DPHB-G could remove Hg from aqueous solution with excellent recyclability and ingestion capacity, and with a Hg removal rate of 98%.

Abnormal formaldehyde (FA) is known to induce a variety of diseases. Herein, we report a novel and efficient method for ultrasensitive detection of formaldehyde in gas and solutions by a catalyst preplaced sensor based on the pillar[5]­arene derivative (DP5J). By the catalyzation of (CF3SO3)2Bi, DP5J could selectively and sensitively sense formaldehyde through an aggregation-induced emission (AIE) “turn-on” response within 7.5 s, and the detection limits for formaldehyde is 3.27 × 10–9 M. Moreover, a FA test kit was prepared by loading the catalyst (CF3SO3)2Bi preplaced DP5J sensor (DP5J-Bi) on a silica gel plate. The test kit could conveniently and efficiently detect formaldehyde in gas or solution with ultrasensitivity. The catalysts preplaced method and FA reaction-induced AIE fluorescence “turn-on” mechanism is a novel approach to achieve ultrasensitive detection of FA. Importantly, it is also a novel approach for the efficient detection of other volatile organic compounds.