Oblique-incidence Reflectivity Difference Method Research Articles

Characterizing Edible Oils by Oblique-Incidence Reflectivity Difference Combined with Machine Learning Algorithms.

Due to the significant price differences among different types of edible oils, expensive oils like olive oil are often blended with cheaper edible oils. This practice of adulteration in edible oils, aimed at increasing profits for producers, poses a major concern for consumers. Furthermore, adulteration in edible oils can lead to various health issues impacting consumer well-being. In order to meet the requirements of fast, non-destructive, universal, accurate, and reliable quality testing for edible oil, the oblique-incidence reflectivity difference (OIRD) method combined with machine learning algorithms was introduced to detect a variety of edible oils. The prediction accuracy of Gradient Boosting, K-Nearest Neighbor, and Random Forest models all exceeded 95%. Moreover, the contribution rates of the OIRD signal, DC signal, and fundamental frequency signal to the classification results were 45.7%, 34.1%, and 20.2%, respectively. In a quality evaluation experiment on olive oil, the feature importance scores of three signals reached 63.4%, 18.9%, and 17.6%. The results suggested that the feature importance score of the OIRD signal was significantly higher than that of the DC and fundamental frequency signals. The experimental results indicate that the OIRD method can serve as a powerful tool for detecting edible oils.

Oblique-incidence reflectivity difference method combined with deep learning for predicting anisotropy of invisible-bedding shale

Deep learning methodologies have revolutionized prediction in many fields and is potential to do the same in the petroleum industry because of the complex oil–gas reservoir. A limitation remains for dense shale exploration in that the shales with invisible bedding are difficult to characterize measurably because of the considerable complexity of the geological structures. The oblique-incidence reflectivity difference method (OIRD) is sensitive to the surface features and was used to obtain a layered distribution of dielectric properties in shales. In this paper, we report a combination of OIRD and deep learning method to identify the dielectric anisotropy of an invisible-bedding shale. The model performs well and clearly identifies the bedding of the shale based on the output values associated with the probability. Only a single direction was determined to have laminations with widths of 20–60μm. The anisotropy features detected by OIRD also existed in the invisible-bedding shale and were caused by the smaller cracks and denser particles’ orientation relative to general shales. As current dense reservoirs include rich invisible-bedding shales, we believe that the OIRD method combined with deep learning method can help improve the exploration efficiency of shale reservoirs.

Label-Free Real-Time Monitoring of Reactions Between Internalin A and Its Antibody by an Oblique-Incidence Reflectivity-Difference Method

Surface protein internalin (InlA) is a major virulence factor of the food-borne pathogen L. monocytogenes. It plays an important role in bacteria crossing the host's barrier by specific interaction with the cell adhesion molecule E-cadherin. Study of this protein will help to find better ways to prevent listeriosis. In this study, a monoclonal antibody against InlA was used to detect InlA. The reaction was label-free and monitored in real time with an oblique-incidence reflectivity-difference (OI-RD) technique. The kinetic constants k on and k off and the equilibrium dissociation constant K d for this reaction were also obtained. These parameters indicate that the antibody is capable of detecting InlA. Additionally, the results also demonstrate the feasibility of using OI-RD for proteomics research and bacteria detection.

Label-Free and Real-Time Monitor of Binding and Dissociation Processes between Protein A and Swine IgG by Oblique-Incidence Reflectivity Difference Method

Life science has a need for detection methods that are label-free and real-time. In this paper, we have selected staphylococcal protein A (SPA) and swine immunoglobulin G (IgG), and monitor the bindings between SPA and swine IgG with different concentrations, as well as the dissociations of SPA-swine IgG complex in different pH values of phosphate buffer by oblique-incidence reflectivity difference (OIRD) in a label-free and real-time fashion. We obtain the ON and OFF reaction dynamic curves corresponding to the bindings and dissociations of SPA and swine IgG. Through our analysis of the experimental results, we have been able to obtain the damping coefficients and the dissociation time of SPA and swine IgG for different pH values of the phosphate buffer. The results prove that the OIRD technique is a competing method for monitoring the dynamic processes of biomolecule interaction and achieving the quantitative information of reaction kinetics.

Parallel detection and quantitative analysis of specific binding of proteins by oblique-incidence reflectivity difference technique in label-free format

In this work, we parallelly detected the specific binding between microarray targets including 12 different kinds of proteins and the probe solution containing five corresponding antibodies and quantitatively analyzed the interactions between CDH13 and solution phase anti-CDH13 at six different probe concentrations by oblique-incidence reflectivity difference (OIRD) method in label-free format. The detection sensitivity reached 10 ng/mL. The experimental results indicate that the OIRD method is a promising and competing technique not only in research work but also in clinic.

Label-free, real-time detection of the dynamic processes of protein degradation using oblique-incidence reflectivity difference method.

Based on the requirements for studying the dynamic process of proteinase action substrates in life science, we selected six random proteins including 1L-10, SCGB2A2, CENPQ, GST, HK1, KLHL7, as well as five different concentrations of 1L-10 proteins of 1 mg/ml, 0.5 mg/ml, 0.25 mg/ml, 0.125 mg/ml, and 0.0625 mg/ml, and fabricated two types of substrate protein microarrays, respectively. We detected the dynamic processes of proteins degraded by proteinase K using oblique-incidence reflectivity difference (OIRD) method in a label-free and real-time manner. We obtained the relevant degradation velocities and the degradation time. The experimental results demonstrate that OIRD has the ability to study proteinase action substrates which is out of reach of label methods and is expected to offer opportunities to determine protease-substrate relationships on the systems biology level.

Label-free high-throughput and real-time detections of protein interactions by oblique-incidence reflectivity difference method

Selected Mouse IgG of 1 mg/mL as target was fabricated on microarray for 500 sample dots. Label-free and real-time reaction dynamic processes were detected between the microarrays with Goat Anti-mouse IgG of 0.02 mg/mL using the oblique-incidence reflectivity difference (OIRD) method. We obtained the reaction results and the reaction dynamic curves of 500 protein dots. In addition, we also used label-free detection of protein microarrays of 10080 sample dots, including BSA and different concentrations of Mouse IgG and Rabbit IgG, by OIRD. The obtained reaction results between the protein microarray with 1 mg/mL Goat Anti-mouse IgG and 1 mg/mL Goat Anti-rabbit IgG are reported herein. Experimental results show that OIRD can be not only label-free high-throughput detection method for biological microarrays but also label-free real-time detection in the interaction processes of biomolecules.

Label-free detection repeatability of protein microarrays by oblique-incidence reflectivity difference method

We examine the repeatabilities of oblique-incidence reflectivity difference (OIRD) method for label-free detecting biological molecular interaction using protein microarrays. The experimental results show that the repeatabilities are the same in a given microarray or microarray-microarray and are consistent, indicating that OIRD is a promising label-free detection technique for biological microarrays.

Label-free and real-time detection of specific binding of IgG proteins by oblique-incidence reflectivity difference method

The entire interaction process between anti-mouse immunoglobulin-G (IgG) and mouse IgG with a concentration range from 1 to 0.25 mg/mL has been label-free detected by the oblique incidence reflectivity difference (OIRD) method. We achieved the two-dimensional scanning images of OIRD Re{Δp-Δs} intensities before and after interactions as well as the curves of reaction dynamic processes. The experimental results suggest that OIRD method not only can label-free distinguish the different concentrations of proteins and detect biological microarrays, but also can real-time monitor the kinetic processes of biomolecular interactions.

Label-free and real-time detection of antigen-antibody interactions by Oblique-incidence Reflectivity Difference (OIRD) method

We label-free and real-time detected three interaction processes of antigen-antibodies, Human Immunoglobulin G (IgG), Rabbit IgG, and Mouse IgG as the targets, and Goat Anti-human IgG, Goat Anti-rabbit IgG, and Goat Anti-mouse IgG as the probe, by the Oblique-incidence Reflectivity Difference (OIRD) method. The interaction dynamic curves of the OIRD signal, corresponding to the interaction processes of antigen-antibodies, are generated. The reaction times from beginning to equilibrium state are about 1800, 900, and 1200 s for Human IgG, Rabbit IgG, and Mouse IgG, respectively. The experimental results demonstrate that the OIRD method not only can distinguish biomolecular interactions, but also can be used in real-time detection of interactions and dynamic processes of biomolecules.

Label-Free and Real-Time Detection of Antigen-Antibody Capture Processes Using the Oblique-Incidence Reflectivity Difference Technique

We successfully label-free and real-time detect the capture processes of human immunoglobulin G (IgG)/goat anti-human IgG and mouse IgG/goat anti-mouse IgG antigen-antibody pairs with different concentrations using the oblique-incidence reflectivity difference (OIRD) method, and obtain the interaction kinetics curves and the interaction times. The experimental results prove that the OIRD method is a promising technique for label-free and real-time detection of the biomolecular interaction processes and achieving the quantitative information of interaction kinetics.

Label-free and real-time detection of interactional dynamic processes of rabbit IgG with different concentrations and goat anti-rabbit IgG by oblique-incidence reflectivity difference method

We successfully label-free and real-time detecte the interactional dynamic processes of rabbit IgG with different concentrations (1.25 mg/mL, 2.50 mg/mL and 5.00 mg/mL), and goat anti-rabbit IgG with a concentration of 0.02 mg/mL by the oblique-incidence reflectivity difference method (OIRD). The dynamic curves and times of interaction, response to concentration of rabbit IgG, are obtained. The experimental results demonstrate that the OIRD method can not only can distinguish the biomolecular interactions, but also real-time detect the interactional dynamic processes of biomolecules, indicating that the OIRD method has promising and extensive applications for the investigating of biomolecular interactions.

Real-time and label-free detection of biomolecular interactions by oblique-incidence reflectivity difference method

We successfully conduct the label-free and real-time detection of the interactions between epoxy groups and rabbit IgG and 5′ CTT CAG GTC ATG AGC CTG AT 3′ oligonucleotide, and between the hybridization of 5′ CTT CAG GTC ATG AGC CTG AT 3′ and its complementary 3′ GAA GTC CAG TAC TCG GAC TA 5′ oligonucleotide, by the oblique-incidence reflectivity difference (OI-RD) method. The dynamic curves of OI-RD signals, corresponding to the kinetic processes of biomolecular combination or hybridization, are acquired. In our case, the combination of epoxy groups with rabbit IgG and 5′ CTT CAG GTC ATG AGC CTG AT 3′ oligonucleotide need almost one and a half hours and about two hundred seconds, respectively; and the hybridization of the two oligonucleotides needs about five hundred seconds. The experimental results show that the OI-RD is a promising method for the real-time and label-free detection of biomolecular interactions.

Label-Free and High-Throughput Detection of Protein Microarrays by Oblique-Incidence Reflectivity Difference Method

We label-free detected the biological process of preparing a microarray that includes 400 spots of mouse immunoglobulin G (IgG) as well as the specific hybridization between mouse IgG and goat anti-mouse IgG by an oblique-incidence reflectivity difference (OI-RD) method. The detection results after each process including printing, washing, blocking, and hybridization, demonstrate that the OI-RD method can trace the preparation process of a microarray and detect the specific hybridization between antigens and antibodies. OI-RD is a promising method for label-free and high-throughput detection of biological microarrays.

Detection of the specific binding on protein microarrays by oblique-incidence reflectivitydifference method

The specific binding between Cy5-labeled goat anti-mouse ImmunoglobulinG (IgG) and mouse IgG with a concentration range from 625 to104 µg ml − 1 has been detected successfully by the oblique-incidence reflectivity difference (OI-RD)method in each procedure of microarray fabrication. The experimental data prove that theOI-RD method can be employed not only to distinguish the different concentrations inlabel-free fashion but also to detect the antibody–antigen capture. In addition, thedifferential treatment of the OI-RD signals can decrease the negative influences of glassslide as the microarray upholder. Therefore the OI-RD technique has promisingapplications for the label-free and high-throughput detection of protein microarrays.

Detection of hybridization of protein microarrays using an oblique-incidence reflectivity difference method

Mouse-Immunoglobulin G (mouse-IgG) with different concentrations in a range from 1000 to 0.0128 μg/mL and a specific hybridization with goat anti-mouse IgG were detected successfully by using an oblique-incidence reflectivity difference (OI-RD) method. Two detection signals, consisting of an imaginary part (Im{Δp-Δs}) and a real part (Re{Δp-Δs}) of OI-RD, were obtained simultaneously. The detection results of hybridization by OI-RD were in accord with that of traditional fluorescent scans. In particular, we label-freely detected the washed mouse-IgG microarray with a series of concentrations and acquired a linear correlation between OI-RD intensities and the protein concentrations in logarithmic coordinates. The detection sensitivity of OI-RD can reach 14 fg. These experimental results suggest that the OI-RD method has potential applications in proteomics and clinical diagnosis.

Label-free detection of hybridization of oligonucleotides by oblique-incidence reflectivity difference method

The microarrays of 20-base oligonucleotide with different concentrations are detected before and after hybridization by the oblique-incidence reflectivity difference (OI-RD) method. The experimental results prove that OI-RD is a label-free method which can not only distinguish the concentration difference of oligonucleotides before and after the hybridization but also detect the hybridization of short oligonucleotides. At present the OI-RD method can detect 0.39 μmol/L 20-base oligonucleotide or less. These results suggest that the OI-RD method is a promising and potential technique for label-free detection of biological microarrays.

Label-free detection of oligonucleotide microarrays by oblique-incidence reflectivity difference method

Hybridizations between labeled or label-free targets and corresponding 21-base oligonucleotide probes, concentrations of which range from 0.39 to 50 μM, are detected by oblique-incidence reflectivity difference (OI-RD) method and fluorescence detection. The experimental results demonstrate that the OI-RD method can be utilized to not only distinguish whether the hybridization of oligonucleotides happened but also directly tell the different concentrations of the labeled and unlabeled oligonucleotides on the microarrays. The analysis with a classical three-layer model suggests that single-strand DNA tends to lie on epoxy-functionalized glass slide while the double-strand DNA prefers to have a tilted angle with respect to the slide in our experimental situation. The label-free detection of hybridization of oligonucleotides declares that OI-RD is a promising method for label-free and high-throughput detection of the biological microarrays.