Search

Nanofibrillated cellulose (NFC) is becoming popular in the field of anti-counterfeiting material due to its favorable biocompatibility, renewability, and easy modification properties, which give it great potentials as carrier of carbon quantum dots (CQDs). Herein, we report an effective method to fabricate Yb and Er doped CQDs grafted onto dialdehyde NFC (DANFC). Owning to special rheological properties of NFC, a waterborne fluorescent dual anti-counterfeiting ink was rationally designed and successfully prepared by adding NFC to waterborne ink to form a stable network structure and increase the thixotropy and yield stress. The resulting CQDs exhibited both photoluminescence (PL) and up-conversion luminescence (UCPL), emitting blue and green fluorescence at excitation wavelengths of 370 and 980 nm, respectively. The study provides a novel method to prepare the waterborne fluorescent dual anti-counterfeiting ink based on Yb and Er doped CQDs/DANFC composites, which provides a reference for its application in printing and packaging industry., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Here, we report a simple fluorescent strip sensor based on aptamer–quantum dots technology that can meet toxin monitoring demands using ochratoxin A (OTA) as a model toxin. The limit of the detection (LOD) for the fluorescent strip was 1.9 ng mL−1, while the time needed for the detection is only 10 min; this conforms to the standards of World Health Organization (WHO) or better. Overall functional parameters are also better than the analogous characteristics of gold nanoparticle strips.High selectivity was maintained as well, making them suitable for the samples with complex solution composition. [ABSTRACT FROM AUTHOR]