Eva-M02 (Fig.1) using evanescent light excited with waveguide-mode is a high-sensitivity sensor with characteristics suitable for biosensing. In biosensors using evanescent light, surface plasmon resonance (SPR) sensors are well known, Biacore series of GE Healthcare is most famous. But, Eva-M02 has a detection sensitivity in a small body that exceeds the SPR sensor by a factor of 10 or more.
Eva-M02 can be made more sensitive by three orders of magnitude by using colored (absorption in the visible light region) labeling substances such as colloidal gold, which makes immunochromatography more sensitive. In addition, same as SPR sensors and some QCM sensor, Eva-M02 can detect progression of the antigen-antibody reactio in real time as a time-dependent change. In other words, it can measure the concentration of a sample. This function of quantitaive analysis is the most important feature of Eva-M02.
The advantage of waveguide-mode sensors over other biosensing technologies is witten in thechnology page. The features of Eva-M02 are summarized in the following three.
Sensitivity, quantitativity, mobility, simplicity, detection velocity, and cost are balanced in high level.
Compatible with many tests on commercially available diagnostic agents, it can change qualitative → quantitative analysis.
In addition to waveguide-mode sensors, it also has the function of a spectrometer (visible light area) and is compatible with a wide variety of tests.
Using Eva-M02, many objects can be sensed very sensitively and easily. Representative measurement objects are shown below. (In brackets, the measurement mode and detection principle for the object) Specific measurement examples for each measurement object can be download at 使用方法－２ as PDF files.
Viruss (Waveguide-mode sensor / Laveling of antigen-antibody reactions)
Blood factors and other proteins (Waveguide-mode sensor / Laveling of antigen-antibody reactions)
Concentrations of salts, sugars, and proteins in aqueous solutions (Waveguide-mode sensor / Changes in the refractive index)
Turbidity of the solution (Spectrometer / Transmittance)
Fungi such as Escherichia coli (Spectrometer / Changes in absorbance due to chromogenic synthetic substrates)
As a typical measurement example, a schematic diagram explains how to quantitatively measure immunochromatography, which is used in tests for influenza, using Eva-M02.
The detection reagent and the measurement sample are mixed and an antigen-antibody reaction is performed in a tube.(Few minutes)
The mixed solution is poured into the sensor chip and measured the time-dependent change. (Measurement time is about few minutes to 10 minutes.)
Calculate the antigen concentration in the sample from the time(t0～t1) for which the reflectance change (ΔR) reaches the set threshold value.
Eva-M02 basically consists of a pen-case-like body and an iOS-equipped smart device (iPad,iPhone). It is large enough to fit into a female second bag, so it is easy to carry, and it can be kept in a desk drawer when not in use. The power supply of the main unit is a small adapter (AC100V or 12V automotive), so do not choose where to use it.
The method of measurement is very easy. For actual operations, please watch the movie. (Sorry, movie is japanese only)
Measurement requirements are as follows.
Use an appropriate one according to the detection target. Our kits and commercial products can be used, but may not be necessary depending on the measurement content. Detection principles are diverse, including antigen-antibody reactions and chromogenic synthetic substrates.
Spesific usage is as follows "Measurment example".