Three novel highly porous aluminophosphates were synthesized through mild hydrothermal methods. Interestingly, among them, α-NaAlPO4(OH) is polar and exhibits moderate nonlinear optical properties with a short cutoff edge.

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Purpose This paper aims to develop an inexpensive, portable, sensitive and environmentally friendly electrochemical sensor to quantify trace metals. Design/methodology/approach A sensor was constructed by modifying carbon paste electrode for the determination of lead, cadmium and zinc ions using square wave anodic stripping voltammetry (SWASV). The modified electrode was prepared by inserting homogeneous mixture of 2-hydroxy-acetophenonethiosemicarbazone, graphite powder and mineral oil. Various important parameters controlling the performance of the sensor were investigated and optimized. Electrochemical behavior of modified electrode was characterized by cyclic voltammetry. Findings Modified carbon pastes electrodes showed three distinct peaks at −0.50, −0.76 and −1.02 V vs silver/silver chloride corresponding to the oxidation of lead, cadmium and zinc ions at the electrode surface, respectively. The highest peak currents for all the metal ions under study were observed in the phosphate buffer solution at pH 1 with a deposition time of 70 s. The sensor exhibited linear behavior in the range of 0.25-12.5 μg mL-1 for lead and cadmium and 0.25-10.0 μg mL−1 for zinc. The limit of detection was calculated as 78.81, 96.17 and 91.88 ng mL−1 for Pb2+, Cd2+and Zn2+, respectively. The modified electrode exhibited good stability and repeatability. Originality/value A chemically modified electrode with Schiff base was applied to determine the content of cadmium, lead and zinc ions in aqueous solutions using SWASV.

This chapter provides an overview of recent progress towards the design, synthesis, and application of molecularly imprinted polymers (MIPs) as food biosensors. Molecular imprinting is an innovative approach for mimicking natural molecular recognition processes through the preparation of synthetic recognition systems. MIPs are rapidly becoming viable alternatives to natural antibodies for sensor technology. The use of MIPs as sensors for determining the presence of contaminants in food has attracted considerable interest from numerous researchers and earned these materials a special niche as analytical devices for assessing food safety. Research on MIPs is an evolving field with a wide range of applications in manufacturing, processing, analysis, and quality control of foodstuffs. MIPs have several advantages for these uses, including high sensitivity, selectivity and portability, as well as their requirement for small samples. A variety of different transducers have been developed for food sensing, including optical, electrochemical, and mass-based sensors, which are discussed in detail in this chapter.