Supersensitive and reusable perovskite nanocomposite fiber paper for time-resolved single-droplet detection

Traditional test paper cannot be reusable and needs much sample solution. In this study, a reusable perovskite nanocomposite fiber paper consisting of CsPbBr₃ quantum dots in-situ growing in the solid polymer fibers with high concentration is fabricated via microwave and electrospinning methods. RhoB is used as the sample solution because it is a hazardous matter but often occurs in printing and dyeing wastewater or appears in food as additives, and traditional detection system generally requires much sample solution (>1 ml) to concentrate for higher concentrations due to the low detection sensitivity. Just need a droplet of sample solution (<25 μl) can this perovskite fiber paper achieve 0.01 ppm of supersensitive detection, which is superior to a majority of reported detection limit. Different from traditional detection based on luminescence intensity, this detection is a new kind of time-resolved method, so that it gets rid of complex and time-consuming calibration (>1 h) usually in traditional detection, and this time-resolved detection can be achieved within ~3 min. Moreover, this perovskite fiber paper is endowed with recyclable property without losing advantages of supersensitive detection (~0.01 ppm), rapid measuring speed (<3 min), and tiny dosage (<25 μl), which is another advantage than conventional detection systems.