Novel nanoparticle detection method using electrochemical device based on anodic aluminum oxide nanopore membrane

AbstractSome investigations suggest that nanoparticles are potentially the most dangerous because they can also penetrate deeper into lung tissue than other large particles. However, some researchers declare that the research on security of environmental nanoparticles should be on the basis of the standardization of investigation system. Therefore, it is significant to detect nanoparticles for both environmental evaluation and further treatment. In this paper, a method for iron oxide nanoparticle detection was investigated by a novel electrochemical device based on AAO nanopore membrane and preliminary results was taken out which may create novel avenues and applications for nanoparticle detection

Mesoporous SnO2 sensor prepared by carbon nanotubes as template and its sensing properties to indoor air pollutants

AbstractAn effort has been made to develop a kind of mesoporous SnO2 gas sensor for detecting indoor air pollutants such as ethanol, benzene, meta-xylene. Mesoporous SnO2 material has been prepared by sol-gel method joined into multiwall carbon nanotubes as template. The field emission scanning electron microscope (FSEM) was used to characterize the samples, by which the mesoporous structure of SnO2 was obviously observed. The investigation results suggest that the as-prepared mesoporous SnO2 has a good response and reversibility to indoor environmental air pollutants. At last, the selectivity of the mesoporous sensor was investigated

Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review

Detection of DNA sequences has received broad attention due to its potential applications in a variety of fields. As sensitivity of DNA biosensors is determined by signal variation of hybridization events, the signal enhancement is of great significance for improving the sensitivity in DNA detection, which still remains a great challenge. Nanomaterials, which possess some unique chemical and physical properties caused by nanoscale effects, provide a new opportunity for developing novel nanomaterial-based signal-enhancers for DNA biosensors. In this review, recent progress concerning this field, including some newly-developed signal enhancement approaches using quantum-dots, carbon nanotubes and their composites reported by our group and other researchers are comprehensively summarized. Reports on signal enhancement of DNA biosensors by non-nanomaterials, such as enzymes and polymer reagents, are also reviewed for comparison. Furthermore, the prospects for developing DNA biosensors using nanomaterials as signal-enhancers in future are also indicated

Study of Influencing Factors of Dynamic Measurements Based on SnO2 Gas Sensor

Abstract: The gas-sensing behaviour based on a dynamic measurement method of a single SnO2 gas sensor was investigated by comparison with the static measurement. The influencing factors of nonlinear response such as modulation temperature, duty ratio, heating waveform (rectangular, sinusoidal, saw-tooth, pulse, etc.) were also studied. Experimental data showed that temperature was the most essential factor because the changes of frequency and heating waveform could result in the changes of temperature essentially

Trimethylamine Sensors Based on Au-Modified Hierarchical Porous Single-Crystalline ZnO Nanosheets

It is of great significance for dynamic monitoring of foods in storage or during the transportation process through on-line detecting trimethylamine (TMA). Here, TMA were sensitively detected by Au-modified hierarchical porous single-crystalline ZnO nanosheets (HPSCZNs)-based sensors. The HPSCZNs were synthesized through a one-pot wet-chemical method followed by an annealing treatment. Polyethyleneimine (PEI) was used to modify the surface of the HPSCZNs, and then the PEI-modified samples were mixed with Au nanoparticles (NPs) sol solution. Electrostatic interactions drive Au nanoparticles loading onto the surface of the HPSCZNs. The Au-modified HPSCZNs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectrum (EDS), respectively. The results show that Au-modified HPSCZNs-based sensors exhibit a high response to TMA. The linear range is from 10 to 300 ppb; while the detection limit is 10 ppb, which is the lowest value to our knowledge