Highly Efficient Fluorescent Detection of Vitamin B12 Based on the Inner Filter Effect of Dithiol-Functionalized Silver Nanoparticles

Construction of a sensing platform for rapid visual detection of oxytetracycline using AIE/Eu MOFs-based molecularly imprinted ratiometric fluorescent probe

Rapid and accurate field testing for oxytetracycline (OTC) is crucial for ensuring food safety and monitoring environmental pollution. Herein, we report the construction of an aggregation-induced emission metal-organic frameworks (MOFs)-mediated molecularly imprinted ratio metric fluorescent sensor (AIE/Eu@MIPs) for the rapid and selective detection of OTC with high sensitivity. AIE MOFs with ultra-high quantum yield were utilized as the blue fluorescence emission carriers, thus avoiding any compromise between convenience and cost-effectiveness. The detection sensitivity was significantly enhanced by modifying the fluorescence signals, driven by the combined effects of the inner filter effect (IFE) and antenna effect (AE). The detection limit was as low as 21 nM (about 9.67 μg/kg). More importantly, a portable optical sensing platform integrating AIE/Eu@MIPs was developed for visual detection of OTC. The developed probe and portable device-based sensing platform demonstrate considerable potential for on-site detection of OTC in real-world applications.

Advances in Fluorescent Nanosensors for Detection of Vitamin B12

Vitamin B12 plays a significant role in maintaining human health. Deficiency or excess intake of vitamin B12 may cause some diseases. Therefore, it is significant to fabricate sensors for sensitive assay of vitamin B12. In the past few years, a variety of nanomaterials have been developed for the fluorescence detection of vitamin B12 in tablets, injection, human serum and food. In the review, the assay mechanisms of fluorescent nanomaterials for sensing vitamin B12 were first briefly discussed. And the progress of various nanomaterials for fluorescence detection of vitamin B12 were systematically summarized. Furthermore, the sensing performance of fluorescent nanosensors was compared with fluorescent probes. Lastly, the challenges and perspectives about the topic were presented.