On-site sensors based on infinite coordination polymer nanoparticles: Recent progress and future challenge

As a newly emerging fascinating nanomaterial, infinite coordination polymers (ICPs) constructed by metal ions and organic bridging ligands, have spurred growing interests. Compared with other members of the coordination polymer family, for example, porous coordination polymers (PCPs) with crystallinity and well-defined framework, ICPs exhibit highly structural flexibility, excellent adaptive capability of guest encapsulation, and perhaps most importantly, quick response to external stimuli, which make them good candidates for on-site application in analytical fields. In this review, we briefly summarize the recent progress in preparation of functional ICP nanoparticles and their utility for on-site analysis, including fluorescent sensing, electrochemical monitoring and dual-responsive assay. Furthermore, by taking advantage of the stimulus response, the emerging applications of ICPs as precursors for ultra-small nanoparticles with novel analytical properties are introduced. The open questions and key challenges along the way for rational designing on-site probe based on ICP nanoparticles with high sensitivity, selectivity and reliability are also discussed and illustrated, which would inspire future investigations on the development of ICPs-based probes with striking analytical performance for real sample detection in a simple and convenient fashion.