Label-free plasmonic-based biosensing using a gold nanohole array chip coated with a wafer-scale deposited WS monolayer.

This paper reports the fabrication, testing and obtained performance of a plasmonic sensor employing a gold (Au) nanohole array chip coated with tungsten disulphide (WS), which is then functionalized for the detection of protein-protein interactions. A key novelty is that the WS was deposited as a monoatomic layer using a wafer-scale synthesis method that successfully provided a film of both high quality and uniform thickness. The deposited WS film was transferred onto a Au nanohole array chip using a novel method and was subsequently functionalized with biotin.

Low-Cost Method and Biochip for Measuring the Trans-Epithelial Electrical Resistance (TEER) of Esophageal Epithelium.

Trans-epithelial electrical resistance (TEER) is a good indicator of the barrier integrity of epithelial tissues and is often employed in biomedical research as an effective tool to assess ion transport and permeability of tight junctions. The Ussing chamber is the gold standard for measuring TEER of tissue specimens, but it has major drawbacks: it is a macroscopic method that requires a careful and labor intensive sample mounting protocol, allows a very limited viability for the mounted sample, has large parasitic components and low throughput as it cannot perform multiple simultaneous measurements, and this sophisticated and delicate apparatus has a relatively high cost. This paper demonstrates a low-cost home-made "sandwich ring" method which was used to measure the TEER of tissue specimens effectively.

Recent advances in microfluidic methods in cancer liquid biopsy.

Early cancer detection, its monitoring, and therapeutical prediction are highly valuable, though extremely challenging targets in oncology. Significant progress has been made recently, resulting in a group of devices and techniques that are now capable of successfully detecting, interpreting, and monitoring cancer biomarkers in body fluids. Precise information about malignancies can be obtained from liquid biopsies by isolating and analyzing circulating tumor cells (CTCs) or nucleic acids, tumor-derived vesicles or proteins, and metabolites.

Microfluidic and Micromachined/MEMS Devices for Separation, Discrimination and Detection of Airborne Particles for Pollution Monitoring.

Most of the microfluidics-related literature describes devices handling liquids, with only a small part dealing with gas-based applications, and a much smaller number of papers are devoted to the separation and/or detection of airborne inorganic particles. This review is dedicated to this rather less known field which has become increasingly important in the last years due to the growing attention devoted to pollution monitoring and air quality assessment. After a brief introduction summarizing the main particulate matter (PM) classes and the need for their study, the paper reviews miniaturized devices and/or systems for separation, detection and quantitative assessment of PM concentration in air with portable and easy-to-use platforms.

Highlighting the uniqueness in dielectrophoretic enrichment of circulating tumor cells.

Circulating tumor cells (CTCs) play an essential role in the metastasis of tumors, and thus can serve as a valuable prognostic factor for malignant diseases. As a result, the ability to isolate and characterize CTCs is essential. This review underlines the potential of dielectrophoresis for CTCs enrichment.

An integrated on-chip platform for negative enrichment of tumour cells.

The study of cancer cells in blood, popularly called circulating tumour cells (CTCs), has exceptional prospects for cancer risk assessment and analysis. Separation and enrichment of CTCs by size-based methods suffer from a well-known recovery/purity trade-off while methods targeting certain specific surface proteins can lead to risk of losing CTCs due to Epithelial to Mesenchymal Transition (EMT) and thus adversely affect the separation efficiency. A negative selection approach is thus preferred for tumour cell isolation as it does not depend on biomarker expression or defines their physical property as the separation criteria.

Label-free virus identification and characterization using electrochemical impedance spectroscopy.

We demonstrate here the application of electrochemical impedance spectroscopy (EIS) in microfluidic devices for label-free virus identification by means of their specific "signature" and also investigate its feasibility for titer quantitation using two basic approaches. The first one is a method based on identifying so-called "resonance" frequencies manifesting in our microdevices and monitoring their variation as a function of the virus concentration, whereas the second one relies on measuring the relative impedance variation at these "resonance" frequencies. Best results have been obtained for the highest "resonance" frequency (∼80 MHz), which we attribute to be due to both the structure of the microdevice and the extremely small size of the viruses that make their effect significant only at such frequencies.

Design and fabrication of Poly(dimethylsiloxane) arrayed waveguide grating.

We have designed, fabricated and characterized poly(dimethylsiloxane) (PDMS) arrayed waveguide grating (AWG) with four-channel output for operation in the visible light wavelength range. The PDMS AWG was realized based on the single-mode PDMS rib waveguide. The device was designed for 1 nm channel spacing with the wavelength ranging from 639 to 644 nm.

Design and fabrication of poly(dimethylsiloxane) single-mode rib waveguide.

We have designed, fabricated and characterized poly(dimethylsiloxane) (PDMS) single-mode rib waveguides. PDMS was chosen specifically for the core and cladding. Combined with the soft lithography fabrication techniques, it enables an easy integration of microoptical components for lab-on-a-chip systems.

Algorithm and simulation for analysis of bio-images obtained by aperture diffraction based optical MEMS.

This paper proposes a novel method to detect transparent living cells in a transparent microfluidic chamber by optical diffraction of an aperture or an aperture array. Through the analysis of the far-field diffraction pattern, one of the parameters of the cells, including the size, refractive index, or position, can be extracted by the analysis software developed in this paper. Calculations are carried out to discuss the key issues of this MEMS device, and our simulation is verified by diffraction patterns of transparent microparticles on fabricated apertures, recorded via a digital camera.

Design of MEMS devices with optical apertures for the detection of transparent biological cells.

This paper provides a novel technique to detect transparent biological living cells trapped in a microfluidic MEMS device by optical diffraction. The device essentially consists of an optical aperture or an aperture array patterned in metal layer and a microfluidic chamber positioned above the center of the aperture. When the cells in the chamber are illuminated through the aperture, the far-field diffraction pattern can be recorded by a CCD camera or a photodetector array.

An integrated microfluidic platform for magnetic microbeads separation and confinement.

An innovative microfluidic platform for magnetic beads manipulation is introduced, consisting of novel microfabricated 3D magnetic devices positioned in a microfluidic chamber. Each magnetic device comprises of an embedded actuation micro-coil in various design versions, a ferromagnetic pillar, a magnetic backside plate and a sensing micro-coil. The various designs of the micro-coils enable efficient magnetic beads trapping and concentration in different patterns.