Sensitive Fluorescence Detection of Phthalates by Suppressing the Intramolecular Motion of Nitrophenyl Groups in Porous Crystalline Ribbons.

A novel, highly sensitive fluorescence sensor for phthalates is developed by introducing nitrophenyl groups to a trifluorene molecule that can form porous crystalline ribbons. On the basis of single-crystalline analysis and theoretical calculations, we demonstrate that phthalate molecules can diffuse into the caves of crystalline ribbons and effectively suppress the rotation of nitrophenyl groups via noncovalent interactions to enhance the emission. Because of this novel response mechanism, fluorescence detection of phthalates with high sensitivity (the limit of detection of widely used di(2-ethylhexyl) phthalate (DEHP) is 0.03 ppb) and rapid reversible turn-on responses is achieved. Sensitive detection of phthalates released from commercial polyvinyl chloride (PVC) products further illustrate the utility of such a sensor in in situ and real-world applications.

Ultrasensitive Detection of Sulfur Mustard via Differential Noncovalent Interactions.

In this work, we fabricate two types of hierarchical microspheres, i.e., one coassembled from two fluorene-based oligomers (1 and 2) and one self-assembled from a fluorene-based oligomer (1), for ultrasensitive and selective detection of trace sulfur mustard (SM) vapor. On the basis of distinct fluorescence responses of 1-2 coassembled and individual 1 hierarchical microspheres that originate from differential noncovalent interactions between analytes and these sensors, SM vapor can be ultrasensitively detected (30 ppb) and easily discriminated from various sulfides and other potential interferents. Our work that utilizes differential noncovalent interactions to give sensitive and selective fluorescence response patterns represents a new detection approach for SM and other hazardous chemicals.