Detection of biomarkers at low concentrations is essential for early diagnosis of numerous diseases. In many sensitive assays, the target molecules are tagged using fluorescently labeled probes and captured using magnetic beads. Current devices rely on quantifying the target molecules by detecting the fluorescent signal from individual beads. Here, we demonstrate a high-throughput optical modulation biosensing (ht-OMB) system Using the ht-OMB system to detect human Interleukin-8, we demonstrated a limit of detection of 0.14 ng/L and a 4-log dynamic range, values which are on par with the most sensitive devices, but are achieved without their bulk and laborious protocols.

Human epidermal growth factor receptor 2 (HER2) over-expression occurs in 15–20% of breast cancers and it is generally associated with a dismal prognosis. In this work, we report on the use of one-dimensional photonic crystal biochips to detect clinically relevant concentrations of HER2 in human plasma samples. To this aim, we optimized an optical read-out system, combining both label-free and fluorescence detection, which makes use of biochips tailored with specific proteins for specific biological recognition. Our biochips were used to discriminate HER2 positive/negative human plasma samples providing a solid and reliable tool for clinical diagnostics.

In this presentation we will present two types of sensors for detecting SARS-CoV-2 symptoms. The first part of the presentation will address a contact-free sensor while its operation principle involves illuminating the inspected subject with a laser beam and analyzing with artificial intelligence (AI) based algorithms, the temporal-spatial changes occurring in the back scattered secondary 2D speckle patterns captured through properly defocused optics. The sensing is performed from a distance of several meters away and is applied to different regions of the subject’s body. We demonstrate measurements performed from the chest and then we extract various cardio-pulmonary bio-sign (several simultaneously) including the sounds of subject’s heart and lungs (like a remote stethoscope). We also perform measurements from the sclera and search for anomalies in the random eye movements. From those anomalies we estimate amount of saturated oxygen in the blood stream. All of the above-mentioned bio-parameters could be useful for remote early detection of SARS-CoV-2 symptoms. The AI algorithms are applied not only to extract the various bio-signs but also to perform the bio-medical diagnosis. In the second part of the presentation, we will present fiber based sensor that is incorporated into textile and clothing and make them a smart-clothing capable via a non-tight contact way to perform sensing of various vital bio-signs (several simultaneously). The bio-parameters to be sensed are related to cardio-pulmonary activity as well as blood-pressure and thus could be associated with early detection of SARS-CoV-2 symptoms. The fiber sensor is based on enhanced multi-mode fiber while at its output an artificial intelligence (AI) based algorithm analyses the temporal-spatial characterizations of the generated dynamic 2D speckle patterns. The fiber sensors are positioned in several locations in the clothing and can perform the bio-measurement from different organs of the wearer and thus allow a comparative measurement which could assist in obtaining more agnostic and more reliable bio-sensing. The AI algorithms are applied not only to extract the various bio-signs but also to perform the bio-medical diagnosis.

Rapid diagnostics of adventitious agents in biopharmaceutical/cell manufacturing release testing and the fight against viral infection have become critical. Quantitative real-time PCR and CRISPR-based methods rapidly detect DNA/RNA in 1 h but suffer from inter-site variability. Absolute quantification of DNA/RNA by methods such as digital PCR reduce this variability but are currently too slow for wider application. Here, we report a RApid DIgital Crispr Approach (RADICA) for absolute quantification of nucleic acids in 40-60 min. Using SARS-CoV-2 and Epstein-Barr virus (EBV) as a proof-of-concept target, RADICA allows for absolute quantification with high accuracy and low variability, no cross-reactivity to similar targets, and high tolerance to human background DNA. RADICA therefore enables rapid and sensitive absolute quantification of nucleic acids which can be widely applied across clinical, research, and biomanufacturing areas.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to pose a global public health threat. Effective and rapid serological assays are needed to provide valuable information about acute and past viral infections. Using the receptor-binding domain of the SARS-CoV-2 spike protein 1 antigen and a highly sensitive detection technology, termed magnetic modulation biosensing (MMB), we demonstrate a quantitative and rapid SARS-CoV-2 IgG antibody test with high sensitivity and specificity compared with the gold standard ELISA test. The improved analytical and clinical sensitivity of the MMB-based assay can help clinical laboratories provide critical information in a timely manner and monitor the spread of the disease.

Photonic crystals provide unique mechanisms to enhance light-matter interactions and have been widely adopted in optical biosensing. However, traditional photonic crystal biosensors still face significant challenges in cost, repeatability, and accuracy in quantification. Diatoms are unicellular algae in nature which have photonic crystal nanostructures with unique optical properties. In addition, they provide ultra-hydrophilic surface, excellent adsorption capabilities, microfluidic effect, and thin layer chromatography. This talk will provide an overview of our recent research progress in materials synthesis, various applications, and fusion with machine learning for better performance.

The study of the interaction of fibronectin and phosphorylcholine molecules with surfaces is of high relevance to understand the biological performance of bioactive coatings. To accomplish this task, one-dimensional photonic crystals supporting Bloch surface waves were interrogated in label-free and enhanced fluorescence operation modes. In particular, the enhanced fluorescence mode offers the possibility to confirm the presence of proteins with a sharp improvement of the resolution. Bioactive coatings based on fibronectin/ phosphorylcholine have thus the potential to not only enhance the body acceptance of implanted devices, but also extend the lifetime of such devices.

GFR is till date the most used parameter for diagnosing kidney diseases. Nevertheless, tubular secretion and reabsorption play an equally important role in healthy functioning of the kidney. The primary focus of this study is to synthesise novel fluorescent markers for evaluating the three physiological processes of the kidney. This would help diagnosing function-/location-specific abnormality in kidney. Since the ideal goal would be to measure all the kidney parameters altogether using a transcutaneous device, the absorbance and emission wavelength for each marker is designed to be significantly different. This paves way for a wholesome, rapid, and non-invasive technique for kidney diagnosis.

Actin, as microfilaments in the cytoskeleton, is essential biological structure and mechanical properties for cell migration and division. These processes require new probes for visualization of actin. Fluorescent labeling as a traditional method accompanies photo bleaching and formation of free radicals that are harmful for live cells, resulting to hardly find a balance between more signals of observation and less light exposure. Here, we present new nanoparticle probes for continuous visualization of actin. We demonstrate continuous imaging of different cell division phases to reveal actin biological and mechanical properties.

Exosomes have received much attention as biomarkers for the diagnosis and treatment of various diseases such as diabetic cardiomyopathy and cancer. However, it remains an important challenge to quickly and precisely isolate and detect exosomes from various body fluids. Therefore, we selectively separated exosomes using anti-CD63 antibody-conjugated magnetic nanoparticles (anti-CD63 Ab-MNPs). And, to detect the exosomes optically, an aptamer-conjugated PDA liposome (Apt-PDA) was developed to target EpCAM overexpressed on the surface of cancer-derived exosome. The isolated exosomes were detected through the colorimetric change and the red fluorescence of PDA. We demonstrated simultaneous separation and detection of exosomes by anti-CD63 Ab-MNPs and anti-EpCAM Apt-PDA.

Red fluorescent proteins (RFPs) and biosensors built upon them provide an attractive advantage for two-photon laser microscopy because they can report from deeper layers of tissue compared to green fluorescent proteins. Using mCherry RFP we show that although the shorter wavelength excitation (740–800 nm) is several times more efficient compared to longer wavelength excitation (1000–1200 nm), the photobleaching of chromophore occurs much faster for the former. This can be explained by a different photobleaching mechanism: with higher energy-photons, 3-4 photons are sufficient to reach an energy threshold (ionization potential) and photodetach an electron from the chromophore.

Due to its accessibility, hemodynamics can be imaged in early stage quail embryo hearts longitudinally. Our group has linked abnormal shear stress patterns caused by regurgitant blood flow with resultant congenital heart defects (CHDs). To understand the mechanisms behind the development of these CHDs, it is imperative to image molecular expression at the sites of abnormal shear stress. However, molecular probes for the quail model are not extensive and 3D imaging is needed to accurately identify regions of interest in the looping heart. In this study, we present HCR FISH probes that target the shear stress responsive genes

Intracellular drug target validation and target engagement quantification have proven to be challenging, and all drugs have some degree of non-specific accumulation due to variable drug affinity, biodistribution, pharmacokinetics, and metabolism. Quantification of available drug targets necessitates accounting for both the drug that binds to its target as well as the drug that accumulates in the cells and tissues in a non-specific manner. We have developed a dynamic, fluorescence-based, three-compartment model termed intracellular paired-agent imaging that utilizes fluorophore labeled small molecule therapeutics as imaging agents to measure drug target availability in live cells and tissues.