https://www.selleckchem.com/products/ly3537982.html Residual tetracycline (TC) in animal food caused by abuse of antibiotics leads to many chronic diseases in the human body. The development of a simple and on-site visualization method for TC detection is need of the hour. Herein, a fluorescent europium-based metal-organic framework (Eu-MOF) sensor for visual and rapid detection of TC was developed. Eu-MOF displays a red emission being excited at 260 nm. Upon exposure to TC, significant fluorescence quenching was observed due to the inner filter effect and photoinduced electron transfer. Moreover, the developed sensor was applied for the detection of TC in milk and beef samples with recoveries of 96.1% to 106.3%, respectively. More importantly, a portable test strip based on Eu-MOF was manufactured. It is a highly selective and sensitive portable device for TC detection. The results can be distinguished immediately by naked eyes, making it become an excellent choice to detect TC in real-time application.Based on the successful synthesis of mercaptomethamidophos as a substrate, a novel nanogold/mercaptomethamidophos multi-residue electrochemical biosensor was designed and fabricated by combining nanoscale effect, strong Au-S bonds as well as interaction between acetylcholinesterase (AChE) and mercaptomethamidophos, which can simultaneously detect 11 kinds of organophosphorus pesticides (OPPs) and total amount of OPPs using indirect competitive method. Electrochemical behavior of the modified electrode was characterized by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The AChE concentration and incubation time were optimized at 37.4 °C to achieve the best detection effect. This biosensor exhibits excellent electrochemical properties with a wider linear range of 0.1 ~ 1500 ng·mL-1, lower detection limit of 0.019 ~ 0.077 ng·mL-1, better stability and repeatability, which realizes the rapid detection of total amount of OPPs, and c