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Herein, an efficient and sensitive methyl parathion (MP) electrochemical sensor was fabricated by using β-cyclodextrin (β-CD) decorated single-wall carbon nanotubes (SCN), which were used to modify the glassy carbon electrode (GCE). The β-CD@SCN/GCE sensor achieved the sensitive MP detection. For the obtained β-CD@SCN nanocomposite, SCN could form three-dimensional reinforced carbon conductive network with good conductivity property and efficient charge transport channels; β-CD could promote the dispersion of carbon materials and boost the accumulation capability of MP on the surface of β-CD@SCN/GCE. The combination of β-CD and SCN significantly optimized the electrochemical property of β-CD@SCN/GCE sensor for the detection of MP. The β-CD@SCN/GCE sensor exhibited good MP electrochemical detection performance with low limit of detection of 7.23 nM. When used for the detection of MP in grape juice, the β-CD@SCN/GCE sensor exhibited good MP electrochemical sensing analysis performance with satisfactory recovery rates (96.54–98.18%) and relative standard deviation values (1.60–2.07%). [ABSTRACT FROM AUTHOR]

Herein, a novel electrochemical sensor was designed for the sensitive determination of methyl parathion (MP) using the Super P Li carbon black@β-cyclodextrin (SPLCB@β-CD) decorated glassy carbon electrode (GCE). SPLCB with high electroactive area exhibited exceptional conductivity and good dispersive property, which is beneficial for forming the interlinked conductive network structure. β-CD could not only promote the uniform dispersion of SPLCB but also effectively realise the enrichment of MP molecules. Moreover, the existence of SPLCB could make up for the defect of poor conductivity of β-CD. Under the optimal experimental condition (pH = 7.0, enrichment time: 60 s). The collaborative cooperation of SPLCB and β-CD achieved the excellent MP detection property (LOD: 8.6 nM; concentration range: 0.01–10 μM). The SPLCB@β-CD/GCE sensor exhibited acceptable repeatability and reproducibility. In addition, the proposed sensor was successfully employed to detect MP in apple juice (Recoveries: 98.0–98.6%, RSD values: 3.68–4.63%). [ABSTRACT FROM AUTHOR]

We proposed an efficient and scalable ultrasound-assisted approach for the synthesis of functionally integrated nanohybrid of silicon dioxide (SiO 2) nanoparticles and multi-walled carbon nanotubes with graphitization and carboxylation (GCMCN), which was employed to modify the glassy carbon electrode (GCE) for the fabrication of GCMCN@SiO 2 /GCE sensor. Graphitization of GCMCN contributed to the reduction of defect density and enhancement of electrical conductivity, and carboxylation of GCMCN improved the dispersion degree of carbon nanomaterial due to the hydrophilicity of carboxyl groups. SiO 2 nanoparticles possessed abundant binding active sites for target analytes due to the surface hydroxyl groups or silanol groups, which were beneficial for the enrichment of gallic acid (GA) molecules. For the functionally integrated GCMCN@SiO 2 nanocomposite, the interconnected conductive networks of GCMCN presented more efficient charge transport channels, which recompensed the non-conductive property of SiO 2 nanoparticles. Based on the functional collaboration of GCMCN and SiO 2 nanoparticles, the fabricated GCMCN@SiO 2 /GCE sensor presented good GA detection property (GA concentration: 0.01–15 μM, LOD value: 1.99 nM). The proposed sensor exhibited acceptable repeatability, reproducibility, and selectivity. Moreover, the good practicability performance could be effectuated at the GCMCN@SiO 2 /GCE sensor for the quantitative analysis of GA in black tea and green tea samples. [ABSTRACT FROM AUTHOR]

Herein, we reported a simple and sensitive methyl parathion (MP) electrochemical sensor based on the expired mung bean-derived porous carbon (MDPC)-modified glassy carbon electrode (GCE). For the fabricated MDPC/GCE sensor, MDPC presented three-dimensional (3D) interconnected porous carbon structure with good electrical conductivity, which provided more efficient charge transfer channels. Moreover, 3D interconnected porous carbon structure could help enhance the specific surface area and adsorption capacity of sensing electrode. Under the optimal conditions, the fabricated MDPC/GCE sensor showed good MP detection property with acceptable limit of detection of 13.2 nM (Linear MP concentration: 0.1–11 μM). Moreover, the fabricated MP electrochemical sensor presented good reproducibility and repeatability with relatively low relative standard deviation of 4.08% and 2.14%, respectively. The good practical performance could be realised at the fabricated MDPC/GCE sensor with satisfactory recovery (96.2–98.8%) and relative standard deviation (1.92–4.61) for the detection of MP in lake water sample. [ABSTRACT FROM AUTHOR]

We designed a simple and efficient electrochemical sensor for the determination of gallic acid (GA) by modifying the glassy carbon electrode (GCE) with the carboxyl-group functionalized multi-walled carbon nanotubes (MWCNTs-COOH). For this kind of carbon nanomaterial, MWCNTs-COOH possessed good electrical conductivity and enough specific surface area due to the one-dimensional hollow carbon skeleton with high charge transfer efficiency. Moreover, the carboxyl functionalization of MWCNTs-COOH could promote the homogeneous dispersion of multi-walled carbon nanotubes due to the enhanced surface wettability of carboxyl groups, which helped provide larger electrochemical active surface area and more efficient electron transport channels. Based on the above advantages, the fabricated MWCNTs-COOH/GCE sensor showed a low limit of detection of 0.0067 μM in the linear GA concentration range of 0.01-10 μM. In addition, the good reproducibility, repeatability, stability, and selectivity could be obtained at the fabricated sensor. [ABSTRACT FROM AUTHOR]

Efficient and sensitive detection of methyl parathion (MP), an insecticide, is of great significance to food safety and healthy life. In this work, functionalised multi-walled carbon nanotubes after graphitisation and carboxylation (FCNTGC) were applied as a sensitising agent to fabricate the glassy carbon electrode (GCE). The obtained FCNTGC/GCE sensor was successfully used for the sensitive detection of MP. The graphitisation of carbon nanotubes contributes to enhancing the conductive property, and the carboxylation of carbon nanotubes contributes to improving the dispersibility of carbon material. The combination of graphitisation and carboxylation could effectively enhance the electrochemical sensing property towards MP. The fabricated FCNTGC/GCE sensor showed a low limit of detection of 0.00306 μM in a linear concentration range of 0.01–10 µM. In addition, good repeatability and reproducibility could be obtained for the MP detection with the fabricated sensor. [ABSTRACT FROM AUTHOR]

We report a simple, economical and green one-pot hydrothermal strategy to synthesize the bio-derived nitrogen-doped carbon sheets (ONCSs) embedded with zirconia nanoparticles (ZrO 2 NPs) with orange juice as carbon source and solvent. The ONCSs-ZrO 2 NPs composite was further applied in the decoration of glassy carbon electrode (GCE) for electrochemical sensing of methyl parathion. The orange juice-derived ONCSs with graphene-like micromorphology showed good electrical conductivity, large specific surface area, and nitrogen functional groups. They could accelerate the electron transport, provide sufficient electrolyte-electrode interface, and improve the surface wettability, thus forming a suitable microenvironment for the redox reaction of MP. The embedded ZrO 2 NPs in graphene-like ONCSs possessed a strong affinity toward the phosphorus groups on MP molecules, which could promote the preconcentration of MP in the interface of the fabricated sensor and electrolyte. Benefitting from the synergistic effect of ONCSs and ZrO 2 NPs/GCE, the ONCSs-ZrO 2 NPs/GCE sensor exhibited excellent peak current response towards MP with a linear detection range of 0.01–15 μg mL−1 and a low detection limit of 0.115 ng mL−1. Furthermore, the ONCSs-ZrO 2 NPs/GCE sensor presented good capability to investigate the MP levels in romaine and kiwifruit juices with satisfactory recoveries. This work provides a novel and green one-step approach in the development of carbon-based composite materials for high-performance MP electrochemical sensors. [ABSTRACT FROM AUTHOR]

A novel and economical approach was proposed for synthesizing the β-cyclodextrin (β-CD) embellished ginkgo nut-derived porous carbon (GNDPC) with three-dimensional (3D) interconnected honeycomb-like morphology, which was employed to decorate the glassy carbon electrode (GCE) for the construction of methyl parathion (MP) electrochemical sensor (GNDPC@β-CD/GCE) for the first time. GNDPC with higher surface area possessed good adsorptive capacity and superior conductive property because of 3D interconnected honeycomb-like porous carbon network. β-CD improved the dispersibility of GNDPC and enhanced the molecular recognition and accumulation capability of GNDPC towards MP. The synergetic cooperation of β-CD and GNDPC realized the ultrasensitive detection property of MP (Limit of detection: 4.52 nM; Concentration: 0.005–15 μM). The constructed GNDPC@ β-CD/GCE displayed good MP determination feasibility in apple and pear juices (Recovery rate: 95.8–100.1%; Relative standard deviation: 2.12–4.17). This work exhibits a novel approach for the sensitive determination of MP in foods. • 3D honeycomb-like ginkgo nut-derived porous carbon (GNDPC) was modified with β-CD. • GNDPC@ β-CD/GCE sensor was first fabricated for the methyl parathion (MP) detection. • Synergistic combination of GNDPC and CTS enhanced the MP detection performance. • A low limit of detection (4.52 nM) was achieved at the GNDPC@ β-CD/GCE sensor. • GNDPC@ β-CD/GCE sensor showed good practical feasibility in apple and pear juices. [ABSTRACT FROM AUTHOR]

The excessive diquat (DQ) residue poses a serious hazard to the ecological environment and human health. Herein, a simple, low-cost, and scalable ultrasonication-assisted strategy was proposed to fabricate the composite of Super-P carbon black nanoparticles dispersed palygorskite (Pal) nanofiber, which was employed to construct an electrochemical sensor for DQ determination. The Pal/Super-P/GCE sensor exhibited ultrasensitive determination performance with a low detection limit (0.1514 nM) and high sensitivity (44.141 μA μM−1) in the linear DQ concentration range of 0.00050–1.0 μM. The recoveries of the constructed sensor ranged from 95.6 % to 100.3 % when applied to detect DQ in river water, potato, and cucumber. The above enhanced DQ detection performance was primarily due to the synergistic effect of Pal and Super-P. Pal with high adsorption ability and excellent biocompatibility could provide numerous attachment sites for DQ adsorption due to the superior ion-exchange property and plentiful Si-OH on its surface. Super-P with pearl-chain like structure contributed to forming an interconnected conductive network, thus facilitating the homogeneous dispersion of Pal and compensated for the poor conductivity of Pal. This study provides a valuable reference in developing clay-based nanocomposite via ultrasonication-assisted strategy to achieve the application of electrochemical sensor at the ultra-trace levels detection of pesticides. [Display omitted] • Pal/Super-P was prepared by ultrasonication-assisted strategy for DQ detection. • Pal/Super-P shows remarkably enhanced synergistic electrocatalytic effect. • Pal/Super-P/GCE sensor shows a low detection limit of 0.1514 nM. • Pal/Super-P/GCE sensor shows good practicality in real samples. [ABSTRACT FROM AUTHOR]

A sensitive carbendazim (CBZ) electrochemical sensor was designed by using Super-P carbon (SPCN) black@zeolitic-imidazolate-framework-8 (SPCN@ZIF-8) nanocomposite modified glassy carbon electrode (SPCN@ZIF-8/GCE). SPCN with pearl-chain nanostructure presented an integrated highly conductive carbon network, which significantly improved the charge transfer efficiency. ZIF-8 nanoparticles possessed high porosity and large specific surface area, which helped to realize the increasement of adsorption ability and accumulation capacity towards CBZ. Moreover, SPCN with excellent conductivity property not only inhibited the agglomeration of ZIF-8 nanoparticles but also compensated the non-conductive property of ZIF-8 nanoparticles. The functional integration of SPCN and ZIF-8 nanoparticles remarkably enhanced the electrochemical detection performance of the SPCN@ZIF-8/GCE sensor towards CBZ. A simple and sensitive CBZ detection could be achieved at the fabricated SPCN@ZIF-8/GCE sensor with low limit of detection of 7.79 nM (CBZ concentration: 0.01–30 μM). Moreover, the fabricated sensor showed good repeatability, reproducibility, and anti-interference performance. When used for the analysis of CBZ in real samples (tomato juice and apple juice), the SPCN@ZIF-8/GCE sensor showed good CBZ detection performance with acceptable recoveries of 99.1%–102.6% and low RSD values of 2.21%–3.27%. This work demonstrated that the SPCN@ZIF-8/GCE sensor may be a promising sensing platform for the rapid and sensitive detection of CBZ residue. [ABSTRACT FROM AUTHOR]

• Vulcan XC-72@halloysite composite was prepared using ultrasound. • A modified sensor was fabricated to detect the niclosamide. • Vulcan XC-72@halloysite composite had a synergistic effect. • A low detection limit of 3.5 nM was achieved. • Good niclosamide determination effect was obtained in food samples. We report a scalable and controllable ultrasound-assisted strategy for the preparation of Vulcan XC-72 nanoparticles-decorated halloysite nanotubes (HNTs@VXC-72), which was applied to modify glassy carbon electrode (GCE) for the highly sensitive electrochemical determination of niclosamide (NA). For the HNTs@VXC-72 nanocomposite, VXC-72 nanoparticles with excellent electrical conductivity and good dispersing property contributed to the formation of the interconnected conductive network; HNTs possessed good adsorption performance and promoted the electrochemical redox reaction. The research results showed that the combination of VXC-72 nanoparticles and HNTs produced the effect of synergistic enhancement. The HNTs@VXC-72/GCE sensor could show a relatively low detection limit of 3.28 nM in the great linear NA concentration range of 0.01–1 µM. When used for the NA determination in food samples, the HNTs@VXC-72/GCE sensor exhibited good practical feasibility with low RSD and acceptable recoveries, which provided a promising NA determination approach to ensure food safety. [ABSTRACT FROM AUTHOR]

Herein, a cost-effective and scalable ultrasound assisted approach was proposed to prepare the nanocomposite of halloysite nanotubes/zirconia/carbon black (Hal/ZrO 2 /CB), which was used to fabricate a novel electrochemical sensor for the highly sensitive determination of methyl parathion (MP). In the Hal/ZrO 2 /CB nanocomposite, Hal with large specific surface area and numerous active sites could enhance the adsorption capacity and accelerate the redox reaction of MP; ZrO 2 nanoparticles with high affinity toward the phosphate group could contribute to good recognition performance for MP; CB nanoparticles with good dispersibility formed an interconnected pearl-chain-like conductive network. Benefitting from the synergistic effect of the three components, the Hal/ZrO 2 /CB/GCE (glassy carbon electrode) sensor showed a remarkably low detection limit of 5.23 nM in a good linear MP detection range of 0.01–10 μM. The Hal/ZrO 2 /CB/GCE sensor possessed a pretty decent practicality with satisfactory RSD and recovery results for the determination of MP in peach, pear, and apple juices. Therefore, the Hal/ZrO 2 /CB/GCE sensor has important implication on the quite sensitive detection of MP. • Halloysite nanotubes/zirconia/carbon black nanocomposite was prepared by sonication. • With the nanocomposite, a sensor was fabricated for determining methyl parathion (MP). • Components of nanocomposite showed synergistic effect for MP determination. • A remarkably low detection limit of 5.23 nM was achieved with the modified sensor. • This novel sensor exhibited good practical feasibility with satisfactory recoveries. [ABSTRACT FROM AUTHOR]

We reported an one-pot ultrasonic-assisted method for the preparation of palygorskite nanorods/Super P Li carbon nanoparticles-graphitized carbon nanotubes (PNRs/SPCNPs-g-CNTs) nanocomposite, which was used to modify the glassy carbon electrode (GCE) for the fabrication of PNRs/SPCNPs-g-CNTs/GCE sensor. For the PNRs/SPCNPs-g-CNTs nanocomposite, PNRs with good stability presented large specific surface area and high adsorption, which promoted the enrichment of NA molecules on the electrode surface. SPCNPs with pearl chain-like nanostructure exhibited good electrical conductivity, and the combination of SPCNPs and g-CNTs with high graphitization degree formed an interconnected carbon conductive network with excellent electrical conductivity, which enhanced the charge transport efficiency. Moreover, the interconnected carbon conductive network of SPCNPs-g-CNTs not only promoted the dispersion degree of PNRs but also made up for the poor conductivity property of PNRs. When used for the detection of niclosamide (NA), an acceptable limit of detection (3.6 nM) was achieved at the PNRs/SPCNPs-g-CNTs/GCE sensor in linear NA concentration range of 0.01–10 μM. The PNRs/SPCNPs-g-CNTs/GCE sensor exhibited good reproducibility, repeatability, and anti-interference performance. For the practicability measurement, the fabricated sensor showed good practicability with satisfactory recoveries (97.0–102.7%) and low RSD values of 0.99–4.78% for the detection of NA in tap water and lake water samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multifunctional SCN@UIO-66 nanocomposite was prepared by ultrasonic-assisted strategy. • SCN@UIO-66/GCE sensor was firstly developed for the sensitive MP detection. • SCN and UIO-66 had synergistic effect in enhancing the MP detection performance. • SCN@UIO-66/GCE sensor exhibited a low MP detection limit of 8.05 nM. • SCN@UIO-66/GCE sensor showed good practicality in real food samples. In this work, a novel electrochemical sensor was designed based on Zr-based metal–organic framework (UIO-66) nanoparticles embellished single-wall carbon nanotube networks (SCN) for the detection of methyl parathion (MP). The synergistic combination of SCN and UIO-66 nanoparticles could fully exert each advantage to boost the MP electrochemical sensing analysis performance. SCN with one-dimensional hollow nanostructures formed three-dimensional interconnected carbon conductive networks, which possessed excellent conductive properties and acceptable specific surface area, enabling efficient transport of electrons and ions. UIO-66 nanoparticles with Zr-OH groups contributes and porous structure to the good affinity for phosphate groups on MP molecules, which enhanced the selective recognition and enrichment capability of sensing electrode towards MP. Under the multifunctional integration of SCN and UIO-66 nanoparticles, the SCN@UIO-66/GCE sensor could present satisfactory MP electrochemical detection performance (LOD: 8.05 nM, linear MP concentration range: 0.01–10 μM). The satisfactory practical property was realized at the SCN@UIO-66/GCE sensor with satisfactory recovery rates of 98.28–101.95 % and low RSD of 1.23–3.01 % for the electrochemical detection of MP in orange juice and lettuce samples. [ABSTRACT FROM AUTHOR]

We developed an economical and environment-friendly technique for preparing the expired mung bean-derived porous carbon (EMBPC), which possessed large specific surface area and 3D interlinked carbon conductive network. Zirconium dioxide (ZrO 2) nanoparticles were further incorporated into the porous structure of EMBPC to form the EMBPC@ZrO 2 composite, which was served as electrode sensitizer for the fabrication of EMBPC@ZrO 2 /GCE sensor. EMBPC exhibited superior conductivity property and large electroactive area, which helped enhance the charge transfer efficiency between electrolyte and sensing electrode. ZrO 2 nanoparticles with good biocompatibility achieved the efficient adsorption of methyl parathion (MP) owing to the recognition of ZrO 2 towards the phosphate groups of MP. Furthermore, EMBPC with porous carbon conductive structure could make up for the inherent disadvantage of ZrO 2 nanoparticles in the term of electrical conductivity. The EMBPC@ZrO 2 /GCE sensor achieved the highly sensitive MP detection (LOD: 8.77 nM) in linear MP concentration range of 0.01–10 μM. The satisfactory practical property was realized at the EMBPC@ZrO 2 /GCE sensor with satisfactory recovery rates of 91.95–124.72% and low RSD% of 1.21–3.35% for the electrochemical detection of MP in food samples. • Multifunctional EMBPC@ZrO 2 composite was prepared by ultrasonic-assisted strategy. • EMBPC@ZrO 2 /GCE sensor was firstly developed for the methyl parathion (MP) detection. • EMBPC and ZrO 2 had synergistic effect in enhancing the MP detection performance. • EMBPC@ZrO 2 /GCE sensor exhibited a low MP detection limit of 8.77 nM • EMBPC@ZrO 2 /GCE sensor showed good practicality in food samples. [ABSTRACT FROM AUTHOR]

• MBC@CTS composite was prepared by a simple and scalable strategy. • MBC@CTS/GCE sensor was fabricated for the sensitive detection of carbendazim. • Synergistic effect of MBC and CTS enhanced the carbendazim detection performance. • A low limit of detection (20 nM) was achieved at the MBC@CTS/GCE sensor. • MBC@CTS/GCE sensor showed good practical feasibility in juice samples. We reported a simple and scalable strategy for the preparation of mung bean-derived porous carbon@chitosan (MBC@CTS) composite, which was used to optimize the glassy carbon electrode (GCE). The MBC@CTS/GCE sensor was applied for the carbendazim (CBZ) detection. For the MBC@CTS composite, MBC with three-dimensional hierarchical structure presented large specific surface area, good adsorbability, and high electrical conductivity, while CTS had good film-forming property, hydrophilicity performance, and adhesion capacity. The MBC@CTS/GCE sensor exhibited wonderful electrochemical detection performance towards CBZ. Under the optimized conditions, the MBC@CTS/GCE sensor showed a linear concentration range from 0.1 to 20 μM with relatively low limit of detection (LOD) of 20 nM. In addition, the fabricated sensor with good reproducibility, stability, and selectivity were successfully applied for the CBZ detection in apple and tomato juices with low relative standard deviation of 2.4 %–4.2% and satisfactory recoveries of 98.8–103.2%. [ABSTRACT FROM AUTHOR]

• Porous carbon spheres (PCS) were prepared from sugarcane juice (SJ). • SJPCS was modified with β-cyclodextrin (β-CD) to make a composite. • SJPCS@β-CD/GCE sensor was fabricated for the detection of MP. • SJPCS and β-CD have synergistic effect in enhancing the sensing performance. • A low detection limit of 5.87 nM was achieved with the SJPCS@β-CD/GCE sensor. Porous carbon spheres (PCS) derived from expired sugarcane juice (SJ) and modified with β-cyclodextrin (β-CD) were used for the fabrication of SJPCS@β-CD/GCE sensor with glassy carbon electrode (GCE) to detect methyl parathion (MP). SJPCS with interconnected porous structure exhibits excellent electrical conductivity, strong adsorption property, and high specific surface area, while β-CD with molecular recognition property achieves the uniform dispersion of SJPCS and promotes the recognition and adsorption of MP molecules. Thanks to the synergistic combination of SJPCS and β-CD, the SJPCS@β-CD/GCE sensor exhibited respectable MP determination performance with low limit of detection of 5.87 nM in the MP concentration range of 0.01–10 µM. For the MP detection in vegetables (onion, cabbage, spinach), the fabricated sensor showed good practicability with adequate relative standard deviation of 1.06% to 4.25% and satisfactory recoveries of 96.5 to 100.5%. A promising strategy for the rapid determination of methyl parathion in food products was developed. [ABSTRACT FROM AUTHOR]

• 3D porous carbon@chitosan composite was prepared by ultrasonic-assisted green method. • 3D porous carbon shows conductive network, high surface area, and functional groups. • A composite sensor was fabricated for the determination of niclosamide. • 3DHPC@CTS/GCE sensor showed good niclosamide detection performance in food samples. • A very low detection limit of 6.7 nM niclosamide was achieved at the modified sensor. Herein, a simple, low-cost, environment-friendly strategy was proposed to prepare the composite of three-dimensional hierarchical porous carbon and chitosan, which was applied to modify the glass carbon electrode to fabricate an electrochemical sensor for the determination of niclosamide. The three-dimensional porous carbon with interconnected conductive network, high surface area, and self-generated oxygen-containing functional groups was prepared by salt-templating method with glucose as carbon source and eutectic mixture of LiBr/KBr as both activating and pore-forming agent. During the subsequent ultrasonic process, chitosan with excellent filming property, strong adsorption ability, and good dispersibility was successfully decorated on the obtained porous carbon to further enhance the determination performance of niclosamide. Benefitting from the multi-functional integration of three-dimensional hierarchical porous carbon and chitosan, the fabricated sensor presented a low limit of detection (6.7 nM) in the linear concentration range from 0.01 to 10 µM. Moreover, the fabricated sensor could show good repeatability, reproducibility, stability, and selectivity. Most important, the decent practicability for the detection of niclosamide was obtained in different food samples with low relative standard deviation and satisfactory recoveries. This work provides a very valuable reference for the sensitive determination of niclosamide in food samples. [ABSTRACT FROM AUTHOR]