Silica Nanochannels as Nanoreactors for the Confined Synthesis of Ag NPs to Boost Electrochemical Stripping Chemiluminescence of the Luminol-O2 System for the Sensitive Aptasensor.

Herein, we, for the first time, synthesize silver nanoparticles (Ag NPs) within the nanochannels of amino group-functionalized vertically ordered mesoporous silica films (NH2-VMSF) and investigate their coreaction accelerator role in the luminol-dissolved oxygen (O2) electrochemical stripping chemiluminescence (ESCL) system. The synthesized Ag NPs are capable of electrocatalytic reduction of O2 to superoxide radicals, and meanwhile, sliver ions (Ag+) electrochemically stripped from Ag NPs can promote the amount of luminol anion radicals, generating the boosted ECL intensity of the luminol-dissolved O2 system. This proposed Ag NPs@NH2-VMSF on the indium tin oxide electrode was applied to construct the ESCL aptasensor for quantitative determination of prostate-specific antigen (PSA), yielding a low detection limit [0.19 pg/mL (S/N = 3)] and a broad linear dynamic range (1 pg/mL to 100 ng/mL). Furthermore, good analytical performance of PSA in serum with satisfactory recoveries and low relative standard deviation values is achieved by our developed ESCL aptasensor, rendering it a convenient and sensitive method for PSA determination in clinical applications and further broadening the strategy of ESCL techniques.

Ultrasensitive detection of dopamine using Au microelectrodes integrated with mesoporous silica thin films.

An electrochemical method was developed for ultrasensitive and selective detection of dopamine in human serum using mesoporous silica thin film modified gold microelectrodes. Vertically aligned mesoporous silica thin films were deposited onto Au microelectrodes by electrochemically assisted self-assembly (EASA). The mesochannels have uniform pore sizes of 2.1 nm in diameter and a negatively charged wall surface. Cyclic voltammetry reveals effective charge permselectivity through the negatively charged mesoporous channels. By using differential pulse voltammetry, the mesoporous silica thin film modified Au microelectrode can be employed for the ultrasensitive detection of dopamine with a detection limit as low as 0.084 µM. In addition, thanks to the electrostatic and steric effects of the silica mesochannels, excellent anti-interference and anti-fouling properties of the electrochemical sensors are demonstrated.

Vertically-Ordered Mesoporous Silica Films Grown on Boron Nitride-Graphene Composite Modified Electrodes for Rapid and Sensitive Detection of Carbendazim in Real Samples.

Carbendazim (CBZ), a kind of widely used pesticide, is harmful to human health and environmental ecology. Therefore, it is of great importance to detect CBZ in real samples. Herein we report the stable growth of vertically-ordered mesoporous silica films (VMSF) on the glassy carbon electrode (GCE) using boron nitride-reduced graphene oxide (BN-rGO) nanocomposite as an adhesive and electroactive layer. Oxygen-containing groups of rGO and 2D planar structure of BN-rGO hybrid favor the stable growth of VMSF via the electrochemically assisted self-assembly (EASA) method. Combining the good electrocatalytic activity of BN-rGO and the enrichment effect of VMSF, the proposed VMSF/BN-rGO/GCE can detect CBZ with high sensitivity (3.70 µA/µM), a wide linear range (5 nM-7 µM) and a low limit of detection (2 nM). Furthermore, due to the inherent anti-fouling and anti-interference capacity of VMSF, direct and rapid electrochemical analyses of CBZ in pond water and grape juice samples are also achieved without the use of complicated sample treatment processes.

Vertically-Ordered Mesoporous Silica Films for Electrochemical Detection of Hg(II) Ion in Pharmaceuticals and Soil Samples.

Rapid and simple determination of mercury ion (Hg2+) in pharmaceuticals and soil samples is vital for human health and the environmental monitoring. Vertically-ordered mesoporous silica films (VMSF) supported by the indium tin oxide (ITO) electrode surface were prepared by electrochemically assisted self-assembly method and utilized for electrochemical detection of Hg2+. Owing to the negatively charged channel walls and ultrasmall pore diameter, VMSF displays obvious cationic selectivity and has highly electrostatic interaction for Hg2+, giving rise to the strong electrochemical signals. By recording the anodic stripping signals of adsorbed Hg2+ using differential pulse voltammetry, quantitative detection of Hg2+ was achieved with a wide linear range (0.2 µM-20 µM) and a low limit of detection (3 nM). Furthermore, considering the anti-fouling and anti-interference capacity of VMSF, the proposed VMSF/ITO sensor has been successfully applied to detect Hg2+ in pharmaceuticals and soil samples without tedious pretreatment processes of samples.

[Functional brain magnetic resonance imaging in healthy people receiving acupuncture at Waiguan versus Waiguan plus Yanglingquan points: a randomized controlled trial].

OBJECTIVE: To observe the cerebral activating effects of needling at Waiguan (SJ5) versus SJ5 plus Yanglingquan (GB34) points in young healthy volunteers based on the hypothesis of "needling effect of combined acupuncture points relates to the brain activation". METHODS: Sixteen healthy volunteers were randomly divided into SJ5 group and SJ5 plus GB34 group, and there were 8 volunteers in each group. The volunteers in the two groups received needling at corresponding points on the right hand or foot respectively. Nuclear magnetic resonance (1.5T, GE Corporation) was used for functional magnetic resonance imaging (fMRI) of the brain before and during the needling, and the obtained experimental data in the regional brain were processed and analyzed by the method of region of interest (ROI). RESULTS: The ROI activation induced by needling of SJ5 or SJ5 plus GB34 was all relatively concentrated (activation rate more than 4 or activation point more than 10) on bilateral frontal and parietal lobes. There were no significant differences in ROI activation rates of brain regions between the two groups. ROI activation points showed that needling at SJ5 could activate the right cerebellum specifically (P < 0.05, vs SJ5 plus GB34), while needling at SJ5 plus GB34 could activate the left parietal and occipital lobes and bilateral basal ganglion more effectively than activate the other brain regions (P < 0.05, vs SJ5). ROI activation strength showed that needling at SJ5 plus GB34 could more strongly activate the right cerebellum (P < 0.05, vs SJ5). CONCLUSION: Based on fMRI data, a kind of acupuncture point combination of SJ5 and GB34 within the hand-foot Shaoyang meridians, could improve the motor and sensory dysfunctions and equilibrium disturbance. The effect of combined acupuncture points was proved by cerebral activity initially.