Nucleic acid detection is widely used in life science and clinical medical diagnosis. Innovative methods and platform research to improve its key performances are of great significance to ensure population health, promote precision medical technology, and even ensure social stability and development. Most of the existing nucleic acid detection technologies utilized PCR as the amplification method, relying on professional and complex scientific instruments and thus is time-consuming and laborious. Fortunately, RPA offers a feasible alternative. It has the advantages of fast amplification speed, high sensitivity, simple primer design, no temperature cycle control and complex manual operations. However, the detection of amplified products is difficult and costly, and there is a lack of low-cost real-time detection methods with parallel multiple detection abilities. In this work, a label-free and real-time RPA amplicon detection method based on hyperspectral interferometry is presented. A solid-phase biochip helps to capture the RPA product in a real-time meaner and the interference spectrum signal is used to read the solid thickness increment brought by the amplicon. A Fourier domain thickness computation method contributes to calculating the thickness increase and excluding scattering noise. The detection sensitivity reaches 6 copies/reaction and the consuming time is less than 20 min. Moreover, the detection method can also be used for single point mutation readout with the specificity of merelya1%mutation-wild type ratio. Combined with a microfluidic platform, parallel, simultaneous and multiple tests can be realized with 3 microliters.
The rapid and accurate identification and classification of cell types is of great significance in scientific research and clinical diagnosis. We proposed the wide-field hyperspectral interferometry rapid label-free (WHIRL)imaging method. Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. In machine learning, support-vector machine (SVM) is one of most commonly used supervised learning models. We cultured a variety of cells and performed hyperspectral imaging by spot scanning with a spectrometer. Then use the SVM method for classification. The accuracy of distinguishing benign from malignant is >99%, and the accuracy of distinguishing different lung cancer subtypes is >90%,which indicates a promising prospect for cell identification and classification based on WHIRL imaging method.
As a biomarker for the diagnosis and treatment monitoring of various diseases, exosomes widely exist in body fluids such as blood, urine and saliva. However, its small particle size and low content are difficult to enrich. Therefore, a fast, high-purity enrichment method, and a fast, high-sensitivity, high-resolution, and low detection limit detection method are particularly important. We developed an automated fully integrated system for the enrichment and detection of exosomes. Using magnetic beads modified with anionic polymers to capture exosomes, adjust the pH of the exosome solution to acidic, and use the electrostatic adsorption between the positive charge on the surface of exosomes and the negative charge on the surface of the anionic polymer-modified substrate to achieve exosome capture. The captured extracellular vesicles are eluted from the surface of the magnetic beads by using a neutral or slightly alkaline eluent and using electrostatic repulsion to achieve the purpose of separation and enrichment of extracellular vesicles. The method is fast and efficient, can be automated with a small instrument, and can exclude favorable nucleic acid interferences. The eluted exosome protein is fixed on the substrate by chemical modification using quantitative interference exosome surface protein detection technology, and the connection between the exosome surface protein and the antibody is realized by immunoadsorption. Hyperspectral interferometry was used to quantitatively analyze the optical path increment on the substrate surface, to determine whether the exosome sample was bound to the antibody, and to detect the protein content of the exosome surface in parallel. This method can achieve sub-nanometer detection accuracy, and can detect exosomes whose size is smaller than the diffraction limit. Finally, the enrichment and detection of exosomes were automated.
Type 2 diabetes mellitus is one of the most common metabolic diseases in the world. However, frequent blood glucose testing causes continual harm to diabetics, which cannot meet the needs of early diagnosis and long-term tracking of diabetes. Thus non-invasive adjuvant diagnosis methods are urgently needed, enabling early screening of the population for diabetes, the evaluation of diabetes risk, and assessment of therapeutic effects. The human eye plays an important role in painless and non-invasive approaches, because it is considered an internal organ but can be easily be externally observed. We developed an AI model to predict the probability of diabetes from scleral images taken by a specially developed instrument, which could conveniently and quickly collect complete scleral images in four directions and perform artificial intelligence (AI) analysis in 3 min without any reagent consumption or the need for a laboratory. The novel optical instrument could adaptively eliminate reflections and collected shadow-free scleral images. 177 subjects were recruited to participate in this experiment, including 127 benign subjects and 50 malignant subjects. The blood sample and sclera images from each subject was obtained. The scleral image classification model achieved a mean AUC over 0.85, which indicates great potential for early screening of practical diabetes during periodic physical checkups or daily family health monitoring. With this AI scleral features imaging and analysis method, diabetic patients’ health conditions can be rapidly, noninvasively, and accurately analyzed, which offers a platform for noninvasive forecasting, early diagnosis, and long-term monitoring for diabetes and its complications.
Quantitative phase imaging (QPI) has quickly emerged as a powerful tool for label-free living cell morphology and metabolism monitoring. However, for current QPI techniques, interference signals from different layers overlay with each other and impede nanoscale optical sectioning. This phenomenon leads to unsatisfactory performances for optically thick or complex scattering biological samples. To address this challenge, we have developed an alternative quantitative phase microscopy with computational hyperspectral interferometry. Nanoscale optical sectioning could be achieved with Fourier domain spectral decomposition. Morphological fluctuations and refractive index distribution could be reconstructed simultaneously with 89.2 nm axial resolution and 1.91 nm optical path difference sensitivity. With this method, we established a label-free cell imaging system for long-term cellular dry mass measurement and in-situ dynamic single cell monitoring. Different intrinsic cell growth characteristics of dry mass between HeLa cells and Human Cervical Epithelial Cells (HCerEpiC) were studied. The dry mass of HeLa cells consistently increased before M phase, whereas that of HCerEpiC increased and then decreased. The maximum growth rate of HeLa cells was 11.7% higher than that of HCerEpiC. We also use the proposed method and system to explore the relationship between cellular dry mass distributions and drug effects for cancer cells. The results show that cells with higher nuclear dry mass and nuclear density standard deviations were more likely to survive the chemotherapy. The presented work shows potential values for cell growth dynamics research, cell health characterization, medication guidance and adjuvant drug development.
In the domain of biomedical signals measurements, monitoring human physiological parameters is an important issue. With the rapid development of wireless body area network, it makes monitor, transmit and record physiological parameters faster and more convenient. Infants and the elderly completely bedridden are two special groups of the society who need more medical care. According to researches investigating current frontier domains and the market products, the detection of physiological parameters from the excrement is rare. However, urine and faeces contain a large number of physiological information, which are high relative to health. The mainly distributed odour from urine is NH4 and the distributed odour from feces is mainly H2S, which are both could be detected by the sensors. In this paper, we introduce the design and implementation of a portable wireless device based on body area network for real time monitoring to the odour of excrement for health of infants and the elderly completely bedridden. The device not only could monitor in real time the emitted odour of faeces and urine for health analysis, but also measures the body temperature and environment humidity, and send data to the mobile phone of paramedics to alarm or the server for storage and process, which has prospect to monitoring infants and the paralysis elderly.
Eyes-like diagnosis was a traditional Chinese medicine method for many diseases, such as chronic gastritis, diabetes, hypertension etc. There was a close relationship between viscera and eyes-like. White-Eye was divided into fourteen sections, which corresponded to different viscera, so eyes-like was the reflection of status of viscera, in another words, it was an epitome of viscera health condition. In this paper, we developed a novel shadowless imaging technology and system for eyes-like diagnosis in vivo, which consisted of an optical shadowless imaging device for capturing and saving images of patients’ eyes-like, and a computer linked to the device for image processing. A character matching algorithm was developed to extract the character of white-eye in corresponding sections of eyes-like images taken by the optical shadowless imaging device, according to the character of eyes-like, whether there were viscera diseases could be learned. A series of assays were carried out, and the results verified the feasibility of eyes-like diagnosis technique.
Label free point mutation detection is particularly momentous in the area of biomedical research and clinical diagnosis since gene mutations naturally occur and bring about highly fatal diseases. In this paper, a label free and high sensitive approach is proposed for point mutation detection based on hyperspectral interferometry. A hybridization strategy is designed to discriminate a single-base substitution with sequence-specific DNA ligase. Double-strand structures will take place only if added oligonucleotides are perfectly paired to the probe sequence. The proposed approach takes full use of the inherent conformation of double-strand DNA molecules on the substrate and a spectrum analysis method is established to point out the sub-nanoscale thickness variation, which benefits to high sensitive mutation detection. The limit of detection reach 4pg/mm2 according to the experimental result. A lung cancer gene point mutation was demonstrated, proving the high selectivity and multiplex analysis capability of the proposed biosensor.
KEYWORDS: Microfluidics, Point-of-care devices, Lamps, Digital signal processing, Filtering (signal processing), Optical filters, Sensors, Digital Light Processing, Signal processing, Lithium
Point-of-care testing (POCT) for an infectious diseases is the prerequisite to control of the disease and limitation of its spread. A microfluidic chip for detection and classification of four strains of Ebola virus was developed and evaluated. This assay was based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) and specific primers for Ebola Zaire virus, Ebola Sudan virus, Ebola Tai Forest virus and Ebola Bundibugyo virus were designed. The sensitivity of the microfluidic chip was under 103 copies per milliliter, as determined by ten repeated tests. This assay is unique in its ability to enable diagnosis of the Ebola infections and simultaneous typing of Ebola virus on a single chip. It offers short reaction time, ease of use and high specificity. These features should enable POCT in remote area during outbreaks of Ebola virus.
Optical microscopy technology has achieved great improvements in the 20th century. The detection limit has reached about twenty nanometers (with near-field optics, STED, PALM and STORM). But in the application areas such as life science, medical science, clinical treatment and especially in vivo dynamic measurement, mutual restrictions still exist between numeric aperture/magnification and working distance, fluorescent dependent, and between resolution and frame rate/field size, etc. This paper explores a hyperspectral scanning super-resolution label free molecules imaging method based on the white light interferometry. The vertical detection resolution was approximate to 1 nm which is the thickness of a single molecular layer and dynamic measuring range of thickness reaches to 10 μm. The spectrum-shifting algorithm is developed for robust restructure of images when the pixels are overlapped. Micro-biochip with protein binding and DNA amplification could be detected by using this spectral scanning super-resolution molecules imaging in label free. This method has several advantages as following: Firstly, the decoding and detecting steps are combined into one step. It makes tests faster and easier. Secondly, we used thickness-coded, minimized chips instead of a large microarray chip to carry the probes. This accelerates the interaction of the biomolecules. Thirdly, since only one kind of probes are attached to our thickness-coded, minimized chip, users can only pick out the probes they are interested in for a test without wasting unnecessary probes and chips.
This work presents a visualization method for the high-throughput monitoring of antibody-polypeptide binding by integrating a microarray chip with surface plasmon resonance imaging (SPRi). A prism-coupled SPRi system with smart images processing software and a 5×5 polypeptide microarray was developed. The modeling analysis was performed to optimize the system and the materials of prism and chip, looking for the optimal incident wavelength and angle of incidence for dynamic SPRi detection in solution. The system can dynamically monitor 25 tunnels of biomolecule interactions in solution without secondary tag reactants. In addition, this system can determine the specific profile of antibody-polypeptide binding in each tunnel and yield a visual three-dimensional histogram of dynamic combinations in all microarray tunnels. Furthermore, the detection limit of the label-free antibody-polypeptide binding reached 1 pg/μL in a one-step binding test, and an ultrasensitive detection of 10 fg/μL was obtained using three-step cascade binding. Using the peptide microarray, the amount of sample and reagents used was reduced to 80 nL per tunnel, and 20×20 tunnels of biomolecule interactions could be analyzed in parallel in a 7 mm×7 mm microreaction cells. This device and method offer a potential platform for high-throughput and label-free dynamic monitoring multiple biomolecule interactions for drug discovery and basic biomedical research.
Biomolecular interactions can be detected by many established technologies such as fluorescence imaging, surface
plasmon resonance (SPR)[1-4], interferometry and radioactive labeling of the analyte. In this study, we have designed and
constructed a label-free, real-time sensing platform and its operating imaging instrument that detects interactions using
optical phase differences from the accumulation of biological material on solid substrates. This system allows us to
monitor biomolecular interactions in real time and quantify concentration changes during micro-mixing processes by
measuring the changes of the optical path length (OPD). This simple interferometric technology monitors the optical
phase difference resulting from accumulated biomolecular mass. A label-free protein chip that forms a 4×4 probe array
was designed and fabricated using a commercial microarray robot spotter on solid substrates. Two positive control probe
lines of BSA (Bovine Serum Albumin) and two experimental human IgG and goat IgG was used. The binding of multiple
protein targets was performed and continuously detected by using this label-free and real-time sensing platform.
We combined SPRi and protein microarray to build a system for dynamic monitoring of interaction between
biomolecules. With this system, we achieved label-free, real-time and automatic detection of specific antigen-antibody
interactions. Because protein microarray can be high-throughput, and SPRi is able to achieve real-time and simultaneous
monitoring of each probe on the microarray, our system has great potential to realize large-scale and dynamic tracing
interactions among biomolecules, thus facilitating drug discovery, molecular diagnostics, signal pathway studies and
many other fields.
In this paper, we developed a microsphere enhanced and label free high throughput molecular detection based on
SPRI and microarray chips, and a self-built surface plasmon resonance imaging instrument was set. One label-free
protein chip forming a 7× probe array was designed and fabricated using a commercial microarray robot spotter
on chemical modified gold-coated glass slide. Antibody molecules were successfully detected in label-free and
high-throughput method by using this chip. The detection signals on the chip was successfully enhanced by using
microspheres with a diameter of 1 μm.
Biochips have been an advanced technology for biomedical applications since the end of the 20th century. Optical detection systems have been a very important tool in biochip analysis. Microscopes are often inadequate for high resolution and big view-area detection of microarray chips, thus some new optical instruments are required. In this work, a novel digital imaging scanning system with dark-field irradiation is developed for some biomedical applications for microarray chips, characterized by analyzing genes and proteins of clinical samples with high specific, parallel, and nanoliter samples. The novel optical system has a high numerical aperture (NA=0.72), a long working distance (wd>3.0 mm), an excellent contrast and signal-to-noise ratio, a high resolving power close to 3 µm, and an efficiency of collected fluorescence more than two-fold better than that of other commercial confocal biochip scanners. An edge overlap algorithm is proposed for the image restructure of free area detection and correcting scanning position errors to a precision of 1 pixel. A novel algorithm is explored for recognizing the target from the scanning images conveniently, removing noise, and producing the signal matrix of biochip analysis. The digital imaging scanning system is equally as good for the detection of enclosed biochips as it is for the detection of biological samples on a slide surface covered with a glass cover slip or in culture solution. The clinical bacteria identification and serum antibody detection of biochips are described.
Since microscope was invented in 17 century, optical instruments have continued to be an important tool for advanced
investigations in biology and medicine. The step by step development of optical technology has also preceded the
realization of macroscopic and microscopic biology, providing new advances that help better understanding of these
fields. Even today it is necessary to build new optical devices to foster the advancement of frontier biological research,
and for new applications in medical research. Here in this paper, we describe two new advanced optical systems for
biological detection, which are already used in a series of new instrument products, such as the confocal scanner, the
digital imaging scanning system.
Electrorotation (ROT) is widely used for the investigation of the dielectric properties of biological cells. Traditionally the
tedious measurements of the rotational rates of the cells are handled manually. In this paper, a ROT chip detection
platform equipped with computer-aided measuring system is presented. The rotational motions of the cells are captured
by CCD camera and an algorithm is implemented to automatically estimate the rotational rates by analyzing the captured
image. The acquired data is verified by a comparison with manual stop-watch measurements. The experimental results
are accurate and robust against variations in illumination and cellular deformation within maximum 5% deviation from
the manual measurements. Thus the platform as a whole can be employed to detect changes in the cellular membrane
dielectric properties caused by external stimulation, or those occurring naturally.
Surface plasmon resonance (SPR) technique is based on an optical measurement approach that is highly sensitive to the
refractive index unit (RIU) of the sample on its analysis surface. Here, we demonstrate the direct detection of proteins
and small molecules using an advanced SPR technology with a sensitivity that is as good as Fourier transform infrared
(FTIR) spectroscopy. Some quantitative results are reported in this paper.
Fluorescence resonance energy transfer (FRET) has found wide use in structural biology, biochemistry, and cell biology
for measuring intra- and inter-molecular distances in the 1-10 nm range and for obtaining quantitative spatial and
temporal information about the interaction of proteins, lipids, and DNA. The measurements of distances and interactions
are based on the calculation of the fluorescence transfer efficiency using some algorithms to process the acquired images
from several different filter sets. However, FRET measurements can suffer from several sources of distortion because of
cross talk between donor and acceptor fluorophores. In this paper, we measured the FRET efficiency on glass coverslips
using microarray technology and described an algorithm to analyze the FRET data obtained, which is corrected for the
cross talk due to spectral overlap of donor and acceptor molecules. Measurement of the interaction of the donor and
acceptor, which are mixed together or coupled to the respective 3'-end and 5'-end of a single-strand DNA are shown to
document the accuracy of the approach, and allow one to estimate cross talk between the different filter units and to
reveal the relationship of the FRET efficiencies of these two samples relative to the donor and acceptor concentrations.
Binary optics has been interested widely in recent years, where the optical element can be fabricated on a thin glass plate with micro-ion-etching film layer. A novel optical scanning system for gene disease diagnostics is developed in this paper, where four kinds optical devices are used, such as beam arrays splitter, arrays lens, filter arrays element and detection arrays. A soft for binary device designing with iterative method is programmed. Two beam arrays splitters are designed and fabricated, where one devices can divide a beam into the 9x9 arrays , the other will divide a beam into the 13x13 arrays. The beam arrays splitter has a good diffraction efficiency >70%, and an even energy distribution. The gene disease diagnostics system is portable by biochip and binary optics technology.
Laboratory-on-a-chip has been interested widely in recent years, where the sample preparation, bio-chemical reaction, separation, detection and analysis, are performed in a small biochip which is only a fingernall dimension. In order to obtain a high detection sensitivity 1 fluors/micrometers 2 (one fluorescence molecular per square micrometer) in biochip scanning system, it is required that the scanning objective lens is a big numerical aperture (> 0.5), very small focal spot (< 5 micrometers ) and long back focal length (> 3 mm). In this paper, a combined lens is designed for the scanning objective lens, which is with big numerical aperture NA > 0.7, very small focal spot (< 2 micrometers ) and long back focal length (> 3 mm). The phase aberrations of combined lens, including the aspherical aberration and the chromatic aberration corresponding to wavelength 532 nm, 570 nm, 635 nm, 670 nm, are corrected very well. The encircled energy diagram of the lens is good to the diffraction limit. The focal spot diagram, the optical path difference diagram, the transverse ray fan plot and the modulation transfer function, are studied also. A novel confocal scanning system of biochip with the designed combined lens as the objective lens is developed, some experiment results in a multi-channel biochip are obtained.
KEYWORDS: Luminescence, Fluorescence spectroscopy, Signal detection, Confocal microscopy, Biological research, Information operations, Biological detection systems, Biomedical optics, Capillaries, Signal to noise ratio
Fluorescence detection by confocal scanning systems has advantages of large area detection, small focus depth, large numerical aperture, complete laser rejection, low background noise, high sensitivity and S/N ratio. It is a sensitive and precise method to record and analyze results of biological or biomedical assay, such as DNA hybridization assay or micro capillary electrophoresis assay on biochip. Parameters like power of laser or sensitivity of PMT are responsible for signal to noise ration and sensitivity of the system, which should be optimized relative to different situations. The structural design and experimental analysis on parameter optimization of a confocal scanning fluorescence detection system are presented in this paper.
A developed binary image processing to detect the convolution interlaced minimum for recognizing and tracing the moving target is proposed in this paper. A diffraction device, which can divide an incidence light into 33 by 33 arrays evenly is designed and fabricated. A dual channel optical real-time processor with two 33 by 33 diffraction devices is built for parallel performing the recognition and tracing of the moving object. Some measures for compensating scale and rotation distortion for moving recognition are provided. The experimental results show that: a) The moving object can be recognized and traced parallel by one step of operation. b) The scale and rotation distortion of the moving target recognition is insensible. The change of rotation angle to be allowed in moving target recognition is from -25 degrees to +25 degrees.
A novel method to detect the convolution interlaced minimum for recognizing and tracing the moving target is proposed in this paper. A diffraction device, which can divide an incidence light into 33 X 33 arrays evenly is designed and fabricated. With two 33 X 33 diffraction devices, a dual channel optical real-time processor is built for parallel performing the recognition and tracing of the moving target. Some measures for compensating scale and rotation distortion for moving recognition are provided. The experimental results show that: (1) The 33 X 33 diffraction device has a good diffraction efficiency, 62.5%. (2) The moving target can be recognized parallelly by one step of operation. (3) The scale and rotation distortion of the moving target recognition is insensible. The change of rotation angle to be allowed in moving target recognition is from -25 degree(s) to +25 degree(s).
A holographic element for the common CD pick-up to play DVD is designed in this paper. The focus of holographic element is the same as that of the objective lens of CD player. The holographic element is fixed before the objective lens. The focus of DVD player with this holographic element is 8.5 mm, the number aperture is 0.75, and the focusing beam spot is 0.5 um. DVD player with the holographic element is characteristic of compensating the main optical error met in the common CD player well.
Based on nm fabrication technology, a developed player for dual and multilayer disk is proposed in this paper. A multifocus device with focus 8.5 mm is used. The distance between two neighbor focal plane is 0.45 mm. The numeral aperture of the developed player is 0.59, the focusing spot is 0.93 um. The developed player with the multifocus device is not only simple in structure, light in weight, but also can focus automatically at any layer of multilayer disk eve, no mechanical movement. Compared to the common CD player, the developed player is characteristic of only one multifocus device to focus and split beam, where the prism and the grating in common CD player are displaced, but the focusing and the tracing error signals can be obtained conveniently for servo detection.
Based on the binary image algebra algorithm for a hit-or-miss transform of mathematical morphology, a new optoelectronic system with two parallel channels is set up for real-time multiple-object recognition. Two Dammann gratings are used for convolutions in morphological operations. The relation of rotation-recognizing sensitivity to the threshold values is discussed.
Based on mathematical morphology, a novel optical scheme for the real-time preprocessing (removing noise and thinning) of interference fringes has been developed. Three kinds of original interferograms are processed and clear and thin interference fringes have been obtained. The greatest advantage of the scheme is that the preprocessing of fringes can be realized parallelly.
In digital image processing, mathematical morphology (MM) transforms are time-consuming operations if the structure image is very large because of the limited channels of electrical interconnections. Therefore, the inherent 3D free connecting optical method is an appropriate way to realize the MM operations. By analyzing the properties of both MM theory and the devices, we developed a general mathematical morphological image processor that has the advantages of programmability, feedback, and low output noise etc.
Based on the theory of computer generated hologram and fabrication of binary optical element, a new micro-optic element for optical disk memory read-write heads is proposed. This element is small in size (5mm in diameter, 1mm in thickness), light in weight (<0.03g), and high in diffraction efficiency (36.64%). It is with three optical functions required for an optical head, splitting beam, producing the focusing error signal and the tracking error signal. When this micro-optic element is used to replace four conventional optical elements (a diffraction grating, a beam splitter prism, a collimating lens and a cylindrical lens) of common optical head, a sophisticated optical head can be produced.
Based on mathematical morphology and digital umbra shading and shadowing algorithm, a new scheme for realizing the fundamental morphological operation of one dimensional gray images is proposed. The mathematical formula for the parallel processing of 1D gray images is summarized; some important conclusions of morphological processing from binary images to gray images are obtained. The advantages of this scheme is simple in structure, high resolution in gray level, and good in parallelism. It can raise the speed of performing morphological processing of gray images greatly and obtain more accurate results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.