Ultrasonic synthesis of CeO2@organic dye nanohybrid: Environmentally benign rabid electrochemical sensing platform for carcinogenic pollutant in water samples

Abstract

A novel organic-inorganic nile-blue-CeO2 (CeO2/NB) nanohybrid has been synthesized by environmentally benign ultrasonic irradiation method for the selective determination of the environmental pollutant, carcinogenic hydrazine (HZ) in environmental water samples. Hydrophobic dyes have generally been as redox mediators in electrochemical sensors fabrication due to strong electron transfer capacity and they would allow the oxidation and reduction of the analytes at lower potentials. The CeO2 nanoparticles were initially synthesized by the ultrasonic irradiation of Ce(NO3)2, NH4OH and ethylene glycol mixture for 6 h using probe sonicator (20 kHz, 100 W) followed by calcination. The organic-dye NB was then added and ultrasonicated further 30 min for the formation of CeO2/NB nanohybrid material. Various spectroscopic and microscopic tools such as UV-vis and FT-IR spectroscopy, XRD, SEM and high-solution TEM and surface analysis tool Brunauer-Emmett-Teller (BET) confirm the formation of the nanohybrid. HR-TEM images showed the well-covered CeO2 on NB molecules and the average size of the nanohybrid is ~35 nm. For the fabrication of environmental pollutant electrochemical sensor, the prepared CeO2/NB nanohybrid was drop-casted on the electrode surface and utilized for the determination of HZ. The nanohybrid modified electrode exhibits higher electrocatalytic activity by showing enhanced oxidation current and less positive potential shift towards HZ oxidation than the bare and individual CeO2 and NB modified electrodes. The fabricated sensor with excellent reproducibility, repeatability, long-term storage stability and cyclic stability exhibited the sensational sensitivity (484.86 µA mM−1 cm−2) and specificity in the presence of 50-fold possible interfering agents with the lowest limit of detection of 57 nM (S/N = 3) against HZ. Utilization of the present sensor in environmental samples with excellent recovery proves it practicability in the determination of HZ in real-time application.

Recent developments in electrochemical sensors for detecting hydrazine with different modified electrodes

“…12). 93 Zhang et al prepared a porous hybrid material from polydopamine-modied MWCNTs and RGO (P-MWCNTs/ RGO). It was employed as a supporting material for an electrochemical HZ sensor.…”

“…Illustration on the mechanism of electrochemical oxidation of HZ at CeO 2 /NB modified electrode. Reused with permission from ref 93…”

Synthesis and characterization of nanoceria for electrochemical sensing applications

“… 102 GCE modified with organic–inorganic nil-blue-CeO 2 nanohybrid was developed for the detection of hydrazine. 103 A nanostructured copper–ceria (CuO–CeO 2 ) composite prepared by calcination of Cu( ii )/Ce( iii ) metal organic framework was developed for the detection of insecticide malathion. 104 An amperometric sensor which contained CeO 2 –CuO modified GCEs was designed for nitrite detection.…”

Negative Potential-Induced Growth of Surfactant-Free CuO Nanostructures on an Al–C Substrate: A Dual In-Line Sensor for Biomarkers of Diabetes and Oxidative Stress

“…On the other hand, the CuO nanostructures grown at −0.3 and −0.5 V exhibit a dominant (1 1 1) plane, and hence, their direction of growth is parallel to the (1 1 1) plane; on the contrary, the CuO nanostructures grown at −0.7 exhibited equally intense (1 1 1) and (2 0 2) planes for their growth. The CuO nanostructures have average crystallite sizes of 17.86, 22.13, 29.47, and 32.14 nm calculated from Scherrer’s equation . The lattice strain on the formed nanostructures was further calculated.…”