Nanochannel array modified three-dimensional graphene electrode for sensitive electrochemical detection of 2,4,6-trichlorophenol and prochloraz

Abstract

Convenient, and sensitive detection of pesticides and their metabolites in environmental or food samples is critical for assessing potential environmental and health risks. Here, a three-dimensional (3D) electrochemical sensing platform is proposed based on the integration of nanochannel array on pre-activated 3D graphene (p-3DG) electrodes with no need of additional adhesive layers, which enables sensitive detection of prochloraz and 2,4,6-trichlorophenol (TCP) in environmental and food samples. Through two-step electrochemical polarization, organic phase anodic oxidation, and aqueous phase cathodic reduction, p-3DG electrodes with high active area and excellent electrocatalytic performance were obtained. Vertically-ordered mesoporous silica-nanochannel film (VMSF) can be rapidly grown on the surface of p-3DG by an electrochemical-assisted self-assembly (EASA) method. Taking advantage of the high electrocatalytic activity of p-3DG and the ability of nanochannels to enrich TCP through hydrogen bonding, the VMSF/p-3DG sensor can sensitively detect TCP in the range of 10 nM to 0.1 μM and 0.1–15 μM with a low limit of detection (LOD) of 2.4 nM. Compared with p-3DG and VMSF-modified 2D electrodes, the fabricated sensor has a wide detection linear range and low LOD. The coexistence of model interferents such as protein, surfactant, and humic acid did not affect the electrochemical response of TCP, confirming the high anti-fouling ability of the VMSF/p-3DG sensor. In addition, prochloraz in vegetable and fruit samples was indirectly determined because TCP was the metabolite of prochloraz.

Electrostatic Nanocage-Confined Probe for Electrochemical Detection of CA19-9 in Human Serum

“…Vertically ordered mesoporous silica films [also termed as silica nanochannel array (SNA)] are a kind of synthetic nanoporous membrane with selective permeability and controlled molecular transport, which enable the design of a vast variety of novel electrochemical/electrochemiluminescent sensors. − Their unique characteristics with respect to the ultrasmall and uniform diameter of silica pores, ultrathin, high porosity, and insulated property especially offer a broad prospect for the direct analysis of complicated biological samples. − Analytes with redox-active characteristic can be directly determined based on their electrochemical signals on the SNA-based sensors. , As for the tumor biomarkers without electroactive property, both recognition elements and probes are employed and the target-introduced large complex on the outer surface of SNA leads to the signal variation of free electrochemical/ECL probes in solution or electrochemical/ECL probes immobilized on the SNA-based sensors and further realizes their quantitative determination. − In contrast, probes immobilized into the nanochannels of SNA offer advantages of easy detection operations, sparing chemical reagents, and low cost without the addition of exogeneous reagents. Su’s group has reported a nanocage consisting of SNA bilayers with different pore diameters for physical trapping ECL probe (tris­(4,7-diphenyl-1,10-phenanthroline)­ruthenium­(II) dichloride), allowing the determination of dopamine released from living PC cells based on the quenching effect .…”

Disposal Immunosensor for Sensitive Electrochemical Detection of Prostate-Specific Antigen Based on Amino-Rich Nanochannels Array-Modified Patterned Indium Tin Oxide Electrode

“…On the one hand, the open and high-density nanochannel array ensures efficient diffusion of small molecules. On the other hand, the ultra-small nanochannels have an ultra-high specific surface area, showing excellent charge-based permselectivity [ 38 , 39 , 40 ]. The variability of VMSF structure endows it with flexible enrichment towards small molecules with different charges [ 40 , 41 ].…”

Fabrication of a Ratiometric Fluorescence Sensor Based on Carbon Dots as Both Luminophores and Nanozymes for the Sensitive Detection of Hydrogen Peroxide

“…Carbon nanomaterials are attractive due to the merits of advantages including their unique structure, multidimensional scale (e.g., zero-dimensional (0D) quantum dots [ 12 , 13 ], 1D nanofibers [ 14 ], nanotubes [ 15 , 16 ], nanoribbons [ 17 ], 2D nanosheets [ 18 , 19 , 20 ], and 3D foams [ 21 , 22 , 23 , 24 ]), and high biocompatibility. Until now, carbonaceous nanomaterials have been widely used in fields such as energy, catalytic processes, sensing, etc.…”