Recent Advancements in Schiff Base Fluorescence Chemosensors for the Detection of Heavy Metal Ions

The Schiff base was first synthesized by Hugo Schiff through the condensation reaction of primary amines with carbonyl compounds (aldehyde or ketone) in 1864. Schiff bases exhibit many structural and electrical characteristics that enable their use in a variety of fields, including medical and chemosensing. Schiff bases generate stable complexes when they bind with different metal ions. Schiff bases are employed as fluorescent turn-on/turn-off chemosensors for the detection of various metal cations, such as Hg2+, Cd2+, Cr3+, Pd2+, and As3+ in various materials due to their outstanding coordination ability. This chapter examines a variety of Schiff bases that are employed in chemosensing procedures for various metal ions (such as divalent and trivalent cations) in various biological, agricultural, and environmental settings

An Ethanol Vapor Sensor Based on a Microfiber with a Quantum-Dot Gel Coating

An ethanol vapor sensor based on a microfiber with a quantum-dot (QD) gel coating is proposed and demonstrated. The QD gel was made from UV glue as the gel matrix and CdSe/ZnS QDs with a concentration of 1 mg/mL. The drawing and coating processes were conducted by using a simple and low-cost system developed for this study. Bending, ethanol sensing, temperature response, and time response tests were carried out, respectively. The experimental results showed that the fabricated sensor had a high sensitivity of −3.3%/ppm, a very low temperature cross-sensitivity of 0.17 ppm/°C, and a fast response time of 1.1 s. The easily fabricated robust structure and the excellent sensing performance render the sensor a promising platform for real ethanol sensing applications