Search

Considering the importance of rapid and effective detection of nitrite in food samples, herein, we report a multistep heterophase synthetic strategy for constructing crystalline-amorphous zinc/cobalt iron porous nanosheets (C-A Zn/Co-Fe PNSs) on carbon cloth. Notably, the C-A Zn/Co-Fe PNSs@CC electrochemical interface consists of interlaced carbon fibers with many uniformly distributed hybrid nanosheets containing crystalline-amorphous interfacial sites. This particular hybrid structure permits local enrichment of nitrite for enhanced nitrite capture efficiency, laying a solid foundation for the ultrasensitive detection of nitrite. In proof-of-concept experiments, we verified that C-A Zn/Co-Fe PNSs@CC could be used to analyze nitrite with good sensitivity and reproducibility. It is worth mentioning that an ultra-low LOD of 0.44 μM was obtained for the detection of nitrite. The designed electrochemical sensor worked well in complex samples such as sausages and tap water under optimal parameters.

Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, Co

A new ratiometric platform was developed for sensing Hg

Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, Co3O4 nanoflowers coupled with ultrafine MoO3 nanoparticles (MoO3/Co3O4) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO3/Co3O4/CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO3 and Co3O4 caused by the heterostructure of MoO3/Co3O4. The electrode achieved a low response time of 2 s, an excellent sensitivity of 1704.1 μA mM−1 cm−2, and a low limit of detection of 0.075 μM (S/N = 3). Furthermore, the electrode displays promise for nitrite detection in complex food such as water and sausages samples. Our study will provide a significant strategy for the application of bimetallic heterostructure to explore the design of sensing interfaces.

Large uptakes of nitrite have been proven to be detrimental to human health, therefore, the development of high-performance nitrite sensors is highly emergent. Herein, a carbon selenide nanofilms modified carbon fiber cloth (CSe2 NF/CC) electrode was obtained via in-situ synthesis to detect nitrite. The electrode integrates the collective merits of macroporous CC and pleated carbon selenide nanofilms, possessing a low overpotential of 0.83 V, a high electrochemical active surface area (EASA) of 5.39 cm2, great electrical conductivity, and fast charge transport as well as ion diffusion. The proposed electrode achieved a low limit of detection of 0.04 μmol L−1 (S/N = 3), a high sensitivity of 2048.56 μA mmol L−1 cm−2, excellent selectivity, and long-term stability. Additionally, the CSe2 NF/CC was successfully used for nitrite detection in different food samples such as pickled vegetables and sausage samples.

Various pesticides employed in modern agriculture result in large amounts of pesticide residues in agricultural production, greatly threatening human health. Herein, we report a facile approach to fabricate a reduced graphene oxide/cyclodextrin modified glassy carbon electrode (rGO/CD/GCE) for the sensitive electrochemical sensing of imidacloprid (IDP). Three different modified electrodes using CDs (α-, β-, γ-CD) were fabricated, and their electrochemical performance was further studied. The results demonstrate that α-CD possesses the best signal amplification for IDP. Compared with wet-chemical synthesis of rGO/CDs (W-rGO/CDs), the electrochemical synthesis of rGO/CDs (E-rGO/CDs) produced sensors that showed better performance for IDP sensing. Taking advantage of prepared E-rGO/α-CD nanocomposite, the fabricated sensor offered a low detection limit (0.02 μM) with a wider linear range (0.5–40 μM) and long-term stability. The new sensor was successfully applied for the detection of IDP in brown rice, providing a new technique for efficient and convenient monitoring of pesticide residues in food.