A novel non-enzymatic glutamate sensor based on nickel nitride nanoparticles modified glassy carbon electrode

Glutamate (Glu) is an amino acid that is virtually present in every food and the main component of many proteins and peptides. It is naturally produced in the human body from glucose and other amino acids and serves as a metabolic energy source. It plays a vital role in human metabolism. Abnormal levels of glutamate in the physiological system have been linked to the development of various neurological diseases such as stroke, Parkinson’s and Alzheimer's disease [۱, ۲]. Therefore, an easy and sensitive analytical method for detection of glutamate is warranted. The electrochemical methods using chemically modified electrodes (CMEs) have been widely used as sensitive and selective analytical methods for the detection of the trace amount of important compounds [۳]. In the present research, nickel nitride as modifier was synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR). CV study showed the Ni۳N/GCE based sensor showed excellent electrocatalytic activity and high stability for determination of Glu. Figure ۱ shows CVs is the absence glutamate of the bare GCE (curve a), the Ni۳N nanoparticles modified GCE (curve b), and as b in present ۰.۲ mM of glutamate (curve c). The Ni۳N modified GCE has higher current than bare GCE, which revealing an improved electroactive surface area and sites owing to that Ni۳N has a large surface area. Amperometric study is performed for exploring the detection sensitivity of Ni۳N nanoparticles modified GCE. The amperometric responses of Ni۳N/GCE on the successive addition of glutamate in to the stirring ۱ M NaOH shown in Figure ۲. The fast electrode response is induced by the fast absorption and activation of glutamate on the surface of the Ni۳N nanoparticles. The corresponding current versus glutamate concentration curve is showed in insert Figure ۲. It shows the Ni۳N/GCE establishes a linear relationship in the ۳۰-۳۶۰ μM range. The detection limit for the glutamate sensor estimated to be ۱۷۴ nM (S/N=۳). The electrochemical sensor exhibits excellent selectivity and stability along with good precision and consistency.