A colorimetric sensor array was developed to characterize and quantify the taste of white wines. A charge-coupled device (CCD) camera captured images of the sensor array from 23 different white wine samples, and the change in the R, G, B color components from the control were analyzed by principal component analysis. Additionally, high performance liquid chromatography (HPLC) was used to analyze the chemical components of each wine sample responsible for its taste. A two-dimensional score plot was created with 23 data points. It revealed clusters created from the same type of grape, and trends of sweetness, sourness, and astringency were mapped. An artificial neural network model was developed to predict the degree of sweetness, sourness, and astringency of the white wines. The coefficients of determination (R²) for the HPLC results and the sweetness, sourness, and astringency were 0.96, 0.95, and 0.83, respectively. This research could provide a simple and low-cost but sensitive taste prediction system, and, by helping consumer selection, will be able to have a positive effect on the wine industry.

Immunomagnetic separation is the laboratory method used to separate targets from heterogeneous samples. It has been applied to separate or detect target entity existing rarely in the sample solution. In this study, a new type of microfluidic device with a 3D micromagnet array was designed, and it was demonstrated that this microfluidic device could be applied to immunomagnetic separation. As the 3D micromagnet is embedded in the microchannel, the height of the microchannel is extended to several hundred micrometers, and the magnetic field pulling the target can be confined to a limited region within the microchannel. Immunomagnetic separation using a microfluidic device was experimentally confirmed by fluorescence imaging. The capture efficiency was maximally 94.9% in the experimental study using the streptavidin-biotin binding of microbeads of the diameter of 1 µ m. As a result, the microfluidic device with micromagnet arrays provides new solution for point-of-care device for immunomagnetic separation.

In the biosensing platform, label‐free detection technique provides advantages such as the short analysis time and the cost‐effectiveness. In this study, we showed the feasibility of the LSPR substrate with gold nanoparticle array for detecting low density lipoprotein (LDL) and high density lipoprotein (HDL) without labeling. The LSPR substrate was fabricated through the lift‐off process with the anodized alumina mask, and its LSPR phenomenon was observed by measuring the optical transmission of substrate. The antibodies were immobilized on the gold nanoparticle array via the chemical binding, in which the 11‐MUA was used as the linker to bind the antibodies. The binding of antibodies was confirmed by observing the shift of LSPR peak of the substrate. Finally, with the LSPR substrates with the antibodies immobilized, the detection of LDL and HDL was investigated. As a result, LDL and HDL could be detected in the clinically available concentration range, respectively.

We report on the enhancement of sensitivity of SPR biosensor by modifying the metal surface. A mixture layer, in which gold and dielectric medium coexist, was simply prepared by increasing the roughness of gold surface deposited onto a glass substrate via the reduction reaction. The absorbance spectrum and atomic force microscopy study showed that the average roughness of modified substrate increased by 4 times, compared to the unmodified substrate. The SPR curves of the unmodified substrate and the modified substrate were measured with the various refractive index of the dielectric medium. The sensitivity of modified substrate to the refractive index of dielectric medium was increased by 1.5 times, compared to the unmodified substrate. In result, the addition of the mixture layer between the gold surface and the dielectric medium by the reduction reaction can provides the enhancement of sensitivity in the SPR biosensor.

Localized surface plasmon resonance (LSPR) is a promising method for detecting antigen‐antibody binding in label‐free biosensors. In this study, the fabrication of a LSPR substrate with a gold nanodot array through the lift‐off process of an alumina mask is reported. The substrate showed an extinction peak in its extinction spectrum, and the peak position was dependent on the height of the gold nanodot array, and the change of extinction peak with the height could be predicted by the numerical simulation. In addition, the peak position was observed to be red‐shifted with the increasing RIU value of the medium surrounding the gold nanodot array. In particular, the peak position in the 10 nm thick gold nanodot array was approximately 710 nm in air, and the sensitivity, defined as the ratio of the shift of peak position to the RIU of the medium, was 323.6 nm/RIU. The fabrication procedure could be applied to fabricate the LSPR substrates with a large area.

Quantum dot (QD) is a kind of semiconductor nanoparticle and shows photoluminescence, in which the light with narrow spectral band is emitted from the QD after the absorption of the excitation light. In this study, it is demonstrated that the LED-based light source combined with a QD film can be applied to spectral imaging. The polymer film with QD was prepared by photopolymerization. Through measurement of the emission spectrum, it was confirmed that the optical intensity at the peak wavelength of the spectral bands of 410 and 540 nm could be controlled by changing the thickness of the film. In the study using a home-made phantom mimicking blood vessels, the patterns’ contrast in the phantom images could be enhanced by using LED combined with QD as compared with the white light image. The LED light combined with the QD film provides a useful solution for illumination for spectral imaging.