A novel ultrasensitive surface plasmon resonance-based nanosensor for nitrite detection

Nitrite is a common food additive, however, its reduction product, nitrosamine, is a strong carcinogen, and hence the ultra-sensitive detection of nitrite is an effective means to prevent related cancers. In this study, different sized gold nanoparticles (AuNPs) were modified with P-aminothiophenol (ATP) and naphthylethylenediamine (NED). In the presence of nitrite, satellite-like AuNPs aggregates formed via the diazotization coupling reaction and the color of the system was changed by the functionalized AuNPs aggregates. The carcinogenic nitrite content could be detected by colorimetry according to the change in the system color. The linear concentration range of sodium nitrite was 0-1.0 μg mL-1 and the detection limit was determined to be 3.0 ng mL-1. Compared with the traditional method, this method has the advantages of high sensitivity, low detection limit, good selectivity and can significantly lower the naked-eye detection limit to 3.0 ng mL-1. In addition, this method is suitable for the determination of nitrite in various foods. We think this novel designed highly sensitive nitrate nanosensor holds great market potential.

Ecofriendly preparation of graphene sheets decorated with an ethylenediamine copper(ii) complex composite modified electrode for the selective detection of hydroquinone in water

A reduced graphene oxide decorated copper(ii) ethylenediamine complex composite modified electrode was applied for the electrochemical determination of hydroquinone.

Environmentally friendly synthesis of CeO2 nanoparticles for the catalytic oxidation of benzyl alcohol to benzaldehyde and selective detection of nitrite

Cerium oxide nanoparticles (CeO₂ NPs) are favorable in nanotechnology based on some remarkable properties. In this study, the crystalline CeO₂ NPs are successfully prepared by an efficient microwave combustion (MCM) and conventional route sol-gel (CRSGM) methods. The structural morphology of the as-prepared CeO₂ NPs was investigated by various spectroscopic and analytical techniques. Moreover, the XRD pattern confirmed the formation of CeO₂ NPs as a face centered cubic structure. The magnetometer studies indicated the low saturation magnetization (23.96 emu/g) of CeO₂ NPs for weak paramagnetic and high saturation magnetization (32.13 emu/g) of CeO₂ NPs for super paramagnetic. After that, the oxidation effect of benzyl alcohol was investigated which reveals good conversion and selectivity. Besides, the CeO₂ NPs modified glassy carbon electrode (GCE) used for the detection of nitrite with linear concentration range (0.02–1200 μM), low limit of detection (0.21 μM) and higher sensitivity (1.7238 μAμM⁻¹ cm⁻²). However, the CeO₂ NPs modified electrode has the fast response, high sensitivity and good selectivity. In addition, the fabricated electrode is applied for the determination of nitrite in various water samples. Eventually, the CeO₂ NPs can be regarded as an effective way to enhance the catalytic activity towards the benzyl alcohol and nitrite.

Multiwalled carbon nanotube supported Schiff base copper complex inorganic nanocomposite for enhanced electrochemical detection of dopamine

A MWCNT/[Cu(sal-ala)bpy] inorganic nanocomposite for the electrochemical detection of dopamine (DA).