Label-free multispectral imaging for biological research and medical diagnostics (Conference Presentation)

Author(s):  
Ewa M. Goldys ◽  
Saabah B. Mahbub ◽  
Jared Campbell ◽  
Abbas Habibalahi ◽  
Ayad G. Anwer ◽  
...  
Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 813 ◽  
Author(s):  
Marta Janczuk-Richter ◽  
Beata Gromadzka ◽  
Łukasz Richter ◽  
Mirosława Panasiuk ◽  
Karolina Zimmer ◽  
...  

Since the norovirus is the main cause of acute gastroenteritis all over the world, its fast detection is crucial in medical diagnostics. In this work, a rapid, sensitive, and selective optical fiber biosensor for the detection of norovirus virus-like particles (VLPs) is reported. The sensor is based on highly sensitive long-period fiber gratings (LPFGs) coated with antibodies against the main coat protein of the norovirus. Several modification methods were verified to obtain reliable immobilization of protein receptors on the LPFG surface. We were able to detect 1 ng/mL norovirus VLPs in a 40-min assay in a label-free manner. Thanks to the application of an optical fiber as the sensor, there is a possibility to increase the user’s safety by separating the measurement point from the signal processing setup. Moreover, our sensor is small and light, and the proposed assay is straightforward. The designed LPFG-based biosensor could be applied in both fast norovirus detection and in vaccine testing.


2020 ◽  
Vol 14 ◽  
Author(s):  
Hung Tri Tran ◽  
Esther H. R. Tsai ◽  
Amanda J. Lewis ◽  
Tim Moors ◽  
J. G. J. M. Bol ◽  
...  

Gaining insight to pathologically relevant processes in continuous volumes of unstained brain tissue is important for a better understanding of neurological diseases. Many pathological processes in neurodegenerative disorders affect myelinated axons, which are a critical part of the neuronal circuitry. Cryo ptychographic X-ray computed tomography in the multi-keV energy range is an emerging technology providing phase contrast at high sensitivity, allowing label-free and non-destructive three dimensional imaging of large continuous volumes of tissue, currently spanning up to 400,000 μm3. This aspect makes the technique especially attractive for imaging complex biological material, especially neuronal tissues, in combination with downstream optical or electron microscopy techniques. A further advantage is that dehydration, additional contrast staining, and destructive sectioning/milling are not required for imaging. We have developed a pipeline for cryo ptychographic X-ray tomography of relatively large, hydrated and unstained biological tissue volumes beyond what is typical for the X-ray imaging, using human brain tissue and combining the technique with complementary methods. We present four imaged volumes of a Parkinson’s diseased human brain and five volumes from a non-diseased control human brain using cryo ptychographic X-ray tomography. In both cases, we distinguish neuromelanin-containing neurons, lipid and melanic pigment, blood vessels and red blood cells, and nuclei of other brain cells. In the diseased sample, we observed several swellings containing dense granular material resembling clustered vesicles between the myelin sheaths arising from the cytoplasm of the parent oligodendrocyte, rather than the axoplasm. We further investigated the pathological relevance of such swollen axons in adjacent tissue sections by immunofluorescence microscopy for phosphorylated alpha-synuclein combined with multispectral imaging. Since cryo ptychographic X-ray tomography is non-destructive, the large dataset volumes were used to guide further investigation of such swollen axons by correlative electron microscopy and immunogold labeling post X-ray imaging, a possibility demonstrated for the first time. Interestingly, we find that protein antigenicity and ultrastructure of the tissue are preserved after the X-ray measurement. As many pathological processes in neurodegeneration affect myelinated axons, our work sets an unprecedented foundation for studies addressing axonal integrity and disease-related changes in unstained brain tissues.


2020 ◽  
Author(s):  
Shah R. Ali ◽  
Dan Nguyen ◽  
Brandon Wang ◽  
Steven Jiang ◽  
Hesham A. Sadek

ABSTRACTProper identification and annotation of cells in mammalian tissues is of paramount importance to biological research. Various approaches are currently used to identify and label cell types of interest in complex tissues. In this report, we generated an artificial intelligence (AI) deep learning model that uses image segmentation to predict cardiomyocyte nuclei in mouse heart sections without a specific cardiomyocyte nuclear label. This tool can annotate cardiomyocytes highly sensitively and specifically (AUC 0.94) using only cardiomyocyte structural protein immunostaining and a global nuclear stain. We speculate that our method is generalizable to other tissues to annotate specific cell types and organelles in a label-free way.


2012 ◽  
Vol 523-524 ◽  
pp. 680-685
Author(s):  
Shuhei Uchida ◽  
Kazuya Yamamura ◽  
Nobuyuki Zettsu

Localized surface plasmon resonance (LSPR) based sensors are a well established technology utilized for label-free biochemical sensing in immunoassay, medical diagnostics and environmental monitoring. The understanding of asymmetric metal nanoparticles, new object for complex, coupled plasmon systems providing localized significantly enhanced E-field, is central to a wide range of novel applications and processes in science of higher sensitive sensing systems. However, few methods are available for actual characterization of such nanostructures at the single particle level. Here we propose a precise and large sized scale fabrication technique for asymmetric nanoshells array with nanogaps of several tens of nanometers for LSPR sensor through atmospheric pressure plasma etching processes. A nanoshell was simply constructed by laminating thin Au films on periodic isolated polymer nanoparticles template. This nanoshells array was expected to exhibit specific near-infrared plasmonic properties. When measuring the sensitivity, nanoshells array exhibited a high sensitivity to changes of surrounding refractive index and showed a higher sensor figure of merit than the alternative structures. This indicated that the enhanced plasmon E-field in the asymmetric nanostructures improved sensor performance. Our fabrication technique and the optical properties of the arrays will provide useful information for developing new plasmonic applications.


2015 ◽  
Vol 112 (32) ◽  
pp. E4354-E4363 ◽  
Author(s):  
Fatih Inci ◽  
Chiara Filippini ◽  
Murat Baday ◽  
Mehmet Ozgun Ozen ◽  
Semih Calamak ◽  
...  

Recent advances in biosensing technologies present great potential for medical diagnostics, thus improving clinical decisions. However, creating a label-free general sensing platform capable of detecting multiple biotargets in various clinical specimens over a wide dynamic range, without lengthy sample-processing steps, remains a considerable challenge. In practice, these barriers prevent broad applications in clinics and at patients’ homes. Here, we demonstrate the nanoplasmonic electrical field-enhanced resonating device (NE2RD), which addresses all these impediments on a single platform. The NE2RD employs an immunodetection assay to capture biotargets, and precisely measures spectral color changes by their wavelength and extinction intensity shifts in nanoparticles without prior sample labeling or preprocessing. We present through multiple examples, a label-free, quantitative, portable, multitarget platform by rapidly detecting various protein biomarkers, drugs, protein allergens, bacteria, eukaryotic cells, and distinct viruses. The linear dynamic range of NE2RD is five orders of magnitude broader than ELISA, with a sensitivity down to 400 fg/mL This range and sensitivity are achieved by self-assembling gold nanoparticles to generate hot spots on a 3D-oriented substrate for ultrasensitive measurements. We demonstrate that this precise platform handles multiple clinical samples such as whole blood, serum, and saliva without sample preprocessing under diverse conditions of temperature, pH, and ionic strength. The NE2RD’s broad dynamic range, detection limit, and portability integrated with a disposable fluidic chip have broad applications, potentially enabling the transition toward precision medicine at the point-of-care or primary care settings and at patients’ homes.


Author(s):  
Olga Bibikova ◽  
Ervin Nippolainen ◽  
Isaac Afara ◽  
Julian Haas ◽  
Vesa Virtanen ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jane Politi ◽  
Ilaria Rea ◽  
Fabrizia Nici ◽  
Principia Dardano ◽  
Monica Terracciano ◽  
...  

Efficient biorecognition of thrombin (TB), a serine protease with crucial role in physiological and pathological blood coagulation, is a hot topic in medical diagnostics. In this work, we investigate the ability of synthetic thrombin aptamer (TBA), immobilized on a gold substrate, to bind thrombin by two different label-free techniques: the quartz crystal microbalance (QCM) and the spectroscopic ellipsometry (SE). By QCM characterization in the range from 20 to 110 nM, we demonstrate high specificity of TBA-TB interaction and determine affinity constant (Kd) of17.7±0.3 nM, system sensitivity of0.42±0.03 Hz nM−1, and limit of detection (LOD) of240±20 pM. The interaction between TBA and TB is also investigated by SE, an all-optical method, by quantifying the thickness increase of the TBA film assembled on gold substrate. AFM characterization of TBA and TB molecules deposited on flat silicon surface is also supplied.


2014 ◽  
Vol 53 (22) ◽  
pp. 5587-5590 ◽  
Author(s):  
Yannyk Bourquin ◽  
Abeer Syed ◽  
Julien Reboud ◽  
Lisa C. Ranford-Cartwright ◽  
Michael P. Barrett ◽  
...  

2021 ◽  
Author(s):  
Matthew Lindley ◽  
Julia Gala de Pablo ◽  
Jorgen Walker Peterson ◽  
Akihiro Isozaki ◽  
Kotaro Hiramatsu ◽  
...  

Cell sorting is the workhorse of biological research and medicine. Cell sorters are commonly used to sort heterogeneous cell populations based on their intrinsic features. Raman-activated cell sorting (RACS) has recently received considerable interest by virtue of its ability to discriminate cells by their intracellular chemical content, in a label-free manner. However, broad deployment of RACS beyond lab-based demonstrations is hindered by a fundamental trade-off between throughput and measurement bandwidth (i.e., cellular information content). Here we overcome this trade-off and demonstrate broadband RACS in the fingerprint region (300 - 1,600 cm-1) with a record high throughput of ~50 cells per second. This represents a 100x throughput increase compared to previous demonstrations of broadband fingerprint-region RACS. To show the utility of our RACS, we demonstrate real-time label-free sorting of microalgal cells based on their accumulation of carotenoids and polysaccharide granules. These results hold promise for medical, biofuel, and bioplastic applications.


Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 49 ◽  
Author(s):  
Georgii Pavliuk ◽  
Dmitrii Pavlov ◽  
Eugeny Mitsai ◽  
Oleg Vitrik ◽  
Aleksandr Mironenko ◽  
...  

We report an easy-to-implement device for surface-enhanced Raman scattering (SERS)-based detection of various analytes dissolved in water droplets at trace concentrations. The device combines an analyte-enrichment system and SERS-active sensor site, both produced via inexpensive and high-performance direct femtosecond (fs)-laser printing. Fabricated on a surface of water-repellent polytetrafluoroethylene substrate as an arrangement of micropillars, the analyte-enrichment system supports evaporating water droplet in the Cassie–Baxter superhydrophobic state, thus ensuring delivery of the dissolved analyte molecules towards the hydrophilic SERS-active site. The efficient pre-concentration of the analyte onto the sensor site based on densely arranged spiky plasmonic nanotextures results in its subsequent label-free identification by means of SERS spectroscopy. Using the proposed device, we demonstrate reliable SERS-based fingerprinting of various analytes, including common organic dyes and medical drugs at ppb concentrations. The proposed device is believed to find applications in various areas, including label-free environmental monitoring, medical diagnostics, and forensics.


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