Ultrasensitive in-vitro monitoring of monoamine neurotransmitters from dopaminergic cells

The design of biosensing assay of monoamine neurotransmitters (MANTs) such as epinephrine (Ep), norepinephrine (NE), and dopamine (DA), as well as the monitoring of these MANTs released from dopaminergic cells, are of particular interest. Electrochemical sensors based on the novel construction of nickel oxides (NiO) were fabricated and employed for electrochemical screening of MANTs. A novel NiO-lacy flower-like (NLF) geometrical structure with semi-spherical head surfaces connected with a trunk as an arm was achieved. The designed semi-spherical head associated with abundant and the well-dispersed tubular branches with needle-like open ends might lead to the creation of vascular vessels for facile diffusion and suitable accommodation of the released MANTs throughout active and wide-surface-area coverage, multi-diffusive pores, and caves with connective open macro-/meso-windows along the entire top-view nanoneedles of lacy flower head and trunk. These electrode surfaces possess high-index catalytic site facets associated with the formation of ridges/defects on {110}-top-cover surface dominants for strong binding, fast response, and signaling of MANTs. The NLF- modified electrode enabled high sensitivity for MANTs and a low limit of detection of 6 nM. Ultrasensitive in-vitro monitoring of DA released from dopaminergic cells (such as PC12) was realized. The NLF electrode was used to detect MANTs from its sources (PC12), and it could be used for clinical diagnosis

Fabrication and characterization of mesoporous silica nanochannels inside the channels of anodic alumina membrane

Brij type surfactants (CnEOx) that have different chemical structures were used to fabricate 3D Mesoporous Silica Nanochannels (MSN) inside the channels of Anodic Alumina Membrane (AAM) under acidic conditions. The fabricated 3D MSN were characterized using TEM-ED, SEM, Small angle XRD, and N2 isotherm. Results revealed that the synthesis of ordered 3D cubic Im3m mesostructures can be formed with tunable pore diameters varied from 4.0 to 4.9 nm that are partially affected with the length of ethylene oxide (EO) group in the template surfactant

Recent Sensing Technologies of Imperceptible Water in Atmosphere

Accurate detection and quantitative evaluation of environmental water in vapor and liquids state expressed as humidity and precipitation play key roles in industrial and scientific applications. However, the development of supporting tools and techniques remains a challenge. Although optical methods such as IR and LASER could detect environmental water in the air, their apparatus is relatively huge. Alternatively, solid detection field systems (SDFSs) could recently lead to a revolution in device downsizing and sensing abilities via advanced research, mainly for materials technology. Herein, we present an overview of several SDFS based sensing categories and their core materials mainly used to detect water in atmosphere, either in the vapor or liquid phase. We considered the governing mechanism in the detection process, such as adsorption/desorption, condensation/evaporation for the vapor phase, and surface attach/detach for the liquid phase. Sensing categories such as optical, chilled mirror, resistive, capacitive, gravimetric sensors were reviewed together with their designated tools such as acoustic wave, quartz crystal microbalance, IDT, and many others, giving typical examples of daily based real scientific applications

Recent Sensing Technologies of Imperceptible Water in Atmosphere

Accurate detection and quantitative evaluation of environmental water in vapor and liquids state expressed as humidity and precipitation play key roles in industrial and scientific applications. However, the development of supporting tools and techniques remains a challenge. Although optical methods such as IR and LASER could detect environmental water in the air, their apparatus is relatively huge. Alternatively, solid detection field systems (SDFSs) could recently lead to a revolution in device downsizing and sensing abilities via advanced research, mainly for materials technology. Herein, we present an overview of several SDFS based sensing categories and their core materials mainly used to detect water in atmosphere, either in the vapor or liquid phase. We considered the governing mechanism in the detection process, such as adsorption/desorption, condensation/evaporation for the vapor phase, and surface attach/detach for the liquid phase. Sensing categories such as optical, chilled mirror, resistive, capacitive, gravimetric sensors were reviewed together with their designated tools such as acoustic wave, quartz crystal microbalance, IDT, and many others, giving typical examples of daily based real scientific applications

Quantitative Correlation between Adsorbed and Condensed Water Mass with Response Galvanic Current Detected at the Micron Gap of Galvanic-Coupled Arrays

Sensor surfaces with micron- and nano-gap scales possess high surface-to-volume ratio which greatly affects their contribution towards water adsorption and condensation. However, the quantitative relationship between adsorbed water molecules and condensed water droplets remains unclear. In this study, we used the humidity-based detected galvanic current within the micron gaps of our newly developed moisture sensor chip (MSC) to emphasize the quantitative relationship between adsorbed water molecules and condensed water droplets. The mass of adsorbed water molecules was detected using a quartz-crystal-microbalance electrode (QCM) whereas the mass of condensed water droplets was estimated microscopically based on their occupying volumes at MSC surface. Experimental results demonstrated that the minimum detection limit of MSC under these experimental conditions was ~150 ng/cm2 for adsorbed water molecules and ~700 ng/ cm2 for condensed water droplets. The detected-response galvanic current arises when a water bridges between two adjacent arrays is found to be linearly correlated to the adsorbed and/or the condensed water’s mass. Such correlation is believed to provide a feasible long-range sensor that can distinguish the status of its surface-existing water either in adsorbed molecular or condensed droplet-wise regimes