Layered double hydroxide nanoparticles/poly (tyrosine) modified electrode for highly sensitive determination of diazepam

Diazepam (DZ) is a medication that belongs to a class of drugs called benzodiazepines. Diazepam is used to treat anxiety, insomnia, acute alcohol withdrawal and seizures. It is also used to relieve muscle spasms and to provide sedation before medical and dental procedures [1]. Since diazepam is widely used in clinical and forensic cases, a rapid, simple and sensitive approach is necessary for its quantification in biological fluids and commercial pharmaceutical products.In recent years, polymerizations of amino acids have attracted considerable attention in the field of electrochemical sensors. The poly amino acid-modified electrodes were extensively used for the determination of various pharmaceutical drugs [2]. Various amino acid modified electrodes have been prepared in recent years by chemical and electrochemical methods for electrochemical sensor applications. Among these, tyrosine (Tyr)-modified electrodes have played a vital role in electrochemical sensors, because of their excellent film stability and electrocatalytic activity [3]. On the other hand, Layered double hydroxides (LDHs) are attractive nano-structured materials as electrode surface modifications due to their unique properties such as large surface area, high chemical stability, low cost, ease of preparation and electrocatalysis properties. The outstanding synergistic effect of LDH nanoparticles and poly (Tyr) leads to the development of a high-performance electrochemical sensor for the analysis of diazepam. The LDH/ poly (Tyr) modified glassy carbon electrode showed good electrocatalytic activity toward the reduction of diazepam as compared with bare electrode. Effect of some parameters in electropolymerization process of Tyr was investigated carefully. Also, effect of experimental condition such as electrolyte solution type, pH, scan rate and etc. were studied. The results demonstrate that the fabricated sensor is a suitable platform for determination of diazepam in real samples.