Tailoring molecular permeability of vertically-ordered mesoporous silica-nanochannel films on graphene for selectively enhanced determination of dihydroxybenzene isomers in environmental water samples.

Hybridized 1D–2D MnMoO4–MXene nanocomposites as high-performing electrochemical sensing platform for the sensitive detection of dihydroxybenzene isomers in wastewater samples

Three-dimensional macroscopic graphene supported vertically-ordered mesoporous silica-nanochannel film for direct and ultrasensitive detection of uric acid in serum.

Three-dimensional macroscopic graphene supported vertically-ordered mesoporous silica-nanochannel film for direct and ultrasensitive detection of uric acid in serum

Developing ordered mesoporous silica-based membranes with highly sensitive detection performance is of great significance for direct electrochemical detection in biological fluids against surface biofouling. Herein, we describe a facile one-step approach for the integration of a vertically-ordered mesoporous silica-nanochannel film (VMSF) with electrochemically reduced graphene oxide (ErGO) by an electrochemically assisted self-assembly (EASA) method. Electrochemical reduction of GO and growth of the VMSF simultaneously occur in a simple one-step process, forming a VMSF/ErGO layer on the glassy carbon electrode (GCE). Arising from the oxygen-containing groups, hydrophobic π-conjugated structure, and the two-dimensional planar structure of ErGO, the VMSF could be stably grown on the GCE surface and it further acted as a protective layer to prevent the internal ErGO electroactive layer from falling off the electrode surface over prolonged use. In comparison with a bare GCE, the present VMSF/ErGO/GCE sensor exhibits an excellent response to doxorubicin with a wide linear range (1 nM−20 μM), a high sensitivity (7.815 μA μM−1) and a low limit of detection (0.77 nM), due to the cooperative signal amplification originating from the electrocatalytic activity and π–π interaction of ErGO and electrostatic preconcentration effect of the VMSF. Furthermore, considering the outstanding anti-fouling and anti-interference ability of the VMSF, direct determination and long-term monitoring of doxorubicin in human whole blood was successfully achieved by the sensor.

Fast one-step fabrication of a vertically-ordered mesoporous silica-nanochannel film on graphene for direct and sensitive detection of doxorubicin in human whole blood

Herein we report the simultaneous determination of serotonin (5-HT) and melatonin (MT) by using highly ordered and vertically-oriented mesoporous silica-nanochannel films (VMSF) on highly electrochemically reduced graphene oxide-carbon nanotubes (HErGO-CNT) composite substrate. Such VMSF/HErGO-CNT with compact 2D-2D layered structure is fabricated on indium tin oxide (ITO) electrodes via a two-step electrochemical process, namely the electrodeposition of ErGO-CNT film onto the ITO surface by cyclic voltammetry and subsequently growth of VMSF on the ErGO-CNT/ITO surface by electrochemically assisted self-assembly method, during which graphene oxide (GO) is subjected to the two-time electrochemical reduction to form HErGO. The CNT encased in the GO sheets served as electronic conducting wires, which not only can promote the electrochemical reduction of GO but also contribute to a certain degree of hydrophobicity, facilitating the controllable electrodeposition of ErGO-CNT composites on ITO under its safe use potential window. In addition, doping CNT is able to enlarge the layer gap between graphene sheets and thus improves the electroactive area and mass transfer of the nanocarbon composite substrate. Furthermore, the underlying HErGO-CNT acts as an efficient electroactive layer and the outer VMSF possesses electrostatic preconcentration and anti-fouling functions, synergistically realizing the direct electrochemical analysis of 5-HT and MT in two complex biological fluids (human whole blood and artificial cerebrospinal fluid).

Vertical silica nanochannels supported by nanocarbon composite for simultaneous detection of serotonin and melatonin in biological fluids

Owing to a nanochannel-based enrichment effect and anti-fouling ability, highly ordered and vertically oriented mesoporous silica thin film (VMSF) modified electrodes have demonstrated their great potential in direct and highly sensitive analysis of complex samples. In this work, a VMSF modified fluorine-doped tin oxide (FTO) electrode (VMSF/FTO) is fabricated for enhanced electrochemiluminescence (ECL) analysis of lidocaine in serum. VMSF with good integrity and mechanical stability can be rapidly and conveniently grown on FTO in a few seconds at room temperature using an electrochemically assisted self-assembly (EASA) method. Due to the strong electrostatic attraction between the cationic ECL probe and negatively charged nanochannel, the VMSF/FTO electrode shows significant enrichment of tris(2,2-bipyridine) ruthenium(II) (Ru(bpy)32+), leading to ∼10 times enhancement of its ECL signal in comparison to the bare FTO electrode. Lidocaine, an anesthetic and antiarrhythmic drug, can act as the co-reactant of Ru(bpy)32+ and promote its ECL signal. Sensitive ECL detection of lidocaine is achieved by the sensor in a wide linear range from 10 nM to 50 μM with a low limit-of-detection (LOD) of 8 nM. Combined with the antifouling ability of VMSF, the VMSF/FTO electrode also realizes the accurate and rapid analysis of lidocaine in real serum samples.

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Vertically oriented mesoporous silica film modified fluorine-doped tin oxide electrode for enhanced electrochemiluminescence detection of lidocaine in serum

Ajabkhan Sailjoi

Papers

Fast one-step fabrication of a vertically-ordered mesoporous silica-nanochannel film on graphene for direct and sensitive detection of doxorubicin in human whole blood

Tailoring molecular permeability of vertically-ordered mesoporous silica-nanochannel films on graphene for selectively enhanced determination of dihydroxybenzene isomers in environmental water samples.

Vertical silica nanochannels supported by nanocarbon composite for simultaneous detection of serotonin and melatonin in biological fluids

Vertically oriented mesoporous silica film modified fluorine-doped tin oxide electrode for enhanced electrochemiluminescence detection of lidocaine in serum