Surface plasmon resonance based-optical biosensor: Emerging diagnostic tool for early detection of diseases

Exploring the Interaction of Biotinylated FcGamma RI and IgG1 Monoclonal Antibodies on Streptavidin-Coated Plasmonic Sensor Chips for Label-Free VEGF Detection

Vascular endothelial growth factor (VEGF) is a critical angiogenesis biomarker associated with various pathological conditions, including cancer. This study leverages pre-biotinylated FcγRI interactions with IgG1-type monoclonal antibodies to develop a sensitive VEGF detection method. Utilizing surface plasmon resonance (SPR) technology, we characterized the binding dynamics of immobilized biotinylated FcγRI to an IgG1-type antibody, Bevacizumab (AVT), through kinetic studies and investigated suitable conditions for sensor surface regeneration. Subsequently, we characterized the binding of FcγRI-captured AVT to VEGF, calculating kinetic constants and binding affinity. A calibration curve was established to analyze the VEGF quantification capacity and accuracy of the biosensor, computing the limits of blank, detection, and quantification at a 95% confidence interval. Additionally, the specificity of the biosensor for VEGF over other protein analytes was assessed. This innovative biomimetic approach enabled FcγRI-mediated site-specific AVT capture, establishing a stable and reusable platform for detecting and accurately quantifying VEGF. The results indicate the effectiveness of the plasmonic sensor platform for VEGF detection, making it suitable for research applications and, potentially, clinical diagnostics. Utilizing FcγRI-IgG1 antibody binding, this study highlights the industrial and clinical value of advanced biosensing technologies, offering insights to enhance therapeutic monitoring and improve outcomes in anti-VEGF therapies.

Liver-on-a-Chip Integrated with Label-Free Optical Biosensors for Rapid and Continuous Monitoring of Drug-Induced Toxicity

Drug toxicity assays using conventional 2D static cultures and animal studies have limitations preventing the translation of potential drugs to the clinic. The recent development of organs-on-a-chip platforms provides promising alternatives for drug toxicity/screening assays. However, most studies conducted with these platforms only utilize single endpoint results, which do not provide real-time/ near real-time information. Here, a versatile technology is presented that integrates a 3D liver-on-a-chip with a label-free photonic crystal-total internal reflection (PC-TIR) biosensor for rapid and continuous monitoring of the status of cells. This technology can detect drug-induced liver toxicity by continuously monitoring the secretion rates and levels of albumin and glutathione S-transferase α (GST-α) of a 3D liver on-a-chip model treated with Doxorubicin. The PC-TIR biosensor is based on a one-step antibody functionalization with high specificity and a detection range of 21.7 ng mL-1 to 7.83 x 103 ng mL-1 for albumin and 2.20 ng mL-1 to 7.94 x 102 ng mL-1 for GST-α. This approach provides critical advantages for the early detection of drug toxicity and improved temporal resolution to capture transient drug effects. The proposed proof-of-concept study introduces a scalable and efficient plug-in solution for organ-on-a-chip technologies, advancing drug development and in vitro testing methods by enabling timely and accurate toxicity assessments.

Principles and Applications of ZnO Nanomaterials in Optical Biosensors and ZnO Nanomaterial-Enhanced Biodetection

Significant research accomplishments have been made so far for the development and application of ZnO nanomaterials in enhanced optical biodetection. The unparalleled optical properties of ZnO nanomaterials and their reduced dimensionality have been successfully exploited to push the limits of conventional optical biosensors and optical biodetection platforms for a wide range of bioanalytes. ZnO nanomaterial-enabled advancements in optical biosensors have been demonstrated to improve key sensor performance characteristics such as the limit of detection and dynamic range. In addition, all nanomaterial forms of ZnO, ranging from 0-dimensional (0D) and 1D to 2D nanostructures, have been proven to be useful, ensuring their versatile fabrication into functional biosensors. The employment of ZnO as an essential biosensing element has been assessed not only for ensembles but also for individual nanomaterials, which is advantageous for the realization of high miniaturization and minimal invasiveness in biosensors and biodevices. Moreover, the nanomaterials' incorporations into biosensors have been shown to be useful and functional for a variety of optical detection modes, such as absorption, colorimetry, fluorescence, near-band-edge emission, deep-level emission, chemiluminescence, surface evanescent wave, whispering gallery mode, lossy-mode resonance, surface plasmon resonance, and surface-enhanced Raman scattering. The detection capabilities of these ZnO nanomaterial-based optical biosensors demonstrated so far are highly encouraging and, in some cases, permit quantitative analyses of ultra-trace level bioanalytes that cannot be measured by other means. Hence, steady research endeavors are expected in this burgeoning field, whose scientific and technological impacts will grow immensely in the future. This review provides a timely and much needed review of the research efforts made in the field of ZnO nanomaterial-based optical biosensors in a comprehensive and systematic manner. The topical discussions in this review are organized by the different modes of optical detection listed above and further grouped by the dimensionality of the ZnO nanostructures used in biosensors. Following an overview of a given optical detection mode, the unique properties of ZnO nanomaterials critical to enhanced biodetection are presented in detail. Subsequently, specific biosensing applications of ZnO nanomaterials are discussed for ~40 different bioanalytes, and the important roles that the ZnO nanomaterials play in bioanalyte detection are also identified.

Cortisol: Biosensing and detection strategies

Cortisol, a crucial steroid hormone synthesized by the adrenal glands, has diverse impacts on multiple physiological processes, such as metabolism, immune function, and stress management. Disruption in cortisol levels can result in conditions like Cushing's syndrome and Addison's disease. This review provides an in-depth exploration of cortisol, covering its structure, various forms in the body, detection methodologies, and emerging trends in cancer treatment and detection. Various techniques for cortisol detection, including electrochemical, chromatographic, and immunoassay methods were discussed and highlighted for their merits and applications. Electrochemical immunosensing emerges as a promising approach, which offered high sensitivity and low detection limits. Moreover, the review delves into the intricate relationship between cortisol and cancer, emphasizing cortisol's role in cancer progression and treatment outcomes. Lastly, the utilization of biomarkers, in-silico modeling, and machine learning for electrochemical cortisol detection were explored, which showcased innovative strategies for stress monitoring and healthcare advancement.

A temperature compensated fiber probe for highly sensitive detection in virus gene biosensing

This research presents an innovative reflective fiber optic probe structure, mutinously designed to detect H7N9 avian influenza virus gene precisely. This innovative structure skillfully combines multimode fiber (MMF) with a thin-diameter seven-core photonic crystal fiber (SCF-PCF), forming a semi-open Fabry-Pérot (FPI) cavity. This structure has demonstrated exceptional sensitivity in light intensity-refractive index (RI) response through rigorous theoretical and experimental validation. The development of a quasi-distributed parallel sensor array, which provides temperature compensation during measurements, has achieved a remarkable RI response sensitivity of up to 532.7 dB/RIU. The probe-type fiber optic sensitive unit, expertly functionalized with streptavidin, offers high specificity in detecting H7N9 avian influenza virus gene, with an impressively low detection limit of 10-2 pM. The development of this biosensor marks a significant development in biological detection, offering a practical engineering solution for achieving high sensitivity and specificity in light-intensity-modulated biosensing. Its potential for wide-ranging applications in various fields is now well-established.

Application and Method of Surface Plasmon Resonance Technology in the Preparation and Characterization of Biomedical Nanoparticle Materials

Surface Plasmon Resonance (SPR) technology, as a powerful analytical tool, plays a crucial role in the preparation, performance evaluation, and biomedical applications of nanoparticles due to its real-time, label-free, and highly sensitive detection capabilities. In the nanoparticle preparation process, SPR technology can monitor synthesis reactions and surface modifications in real-time, optimizing preparation techniques and conditions. SPR enables precise measurement of interactions between nanoparticles and biomolecules, including binding affinities and kinetic parameters, thereby assessing nanoparticle performance. In biomedical applications, SPR technology is extensively used in the study of drug delivery systems, biomarker detection for disease diagnosis, and nanoparticle-biomolecule interactions. This paper reviews the latest advancements in SPR technology for nanoparticle preparation, performance evaluation, and biomedical applications, discussing its advantages and challenges in biomedical applications, and forecasting future development directions.

Ultrasensitive Quantification of MUC16 Antigen/Amine-Terminated Aptamer Interaction by Surface Plasmon Resonance: Kinetic and Thermodynamic Studies

Purpose

MUC16 is a commonly employed biomarker to identify and predict ovarian cancer (OC). Precise measurement of MUC16 levels is essential for the accurate diagnosis, prediction, and management of OC. This research seeks to introduce a new surface plasmon resonance (SPR) biosensor design that utilizes aptamer-based technology to enable the sensitive and real-time detection of MUC16.

Methods

In this study, the sensor chip was immobilized with an anti-MUC16 aptamer (Ap) by utilizing 11-mercaptoundecanoic acid (MUA) as a linker to attach the amine-terminated Ap to the chip using EDC/NHS chemistry.

Results

The results indicated that the newly created aptasensor had a detection limit of 0.03 U/mL for MUC16 concentration, with a linear range of 0.09 to 0.27 U/mL. The findings demonstrate good precision and accuracy (<15%) for each MUC16 concentration, with recoveries ranging from 93% to 96%. Additionally, the aptasensor exhibited high selectivity, good repeatability, stability, and applicability in real human serum samples, indicating its potential as a valuable tool for the diagnosis and treatment of OC.

Conclusion

According to the outcomes, the designed aptasensor exhibited acceptable specificity to detect the CA125 antigen and could be utilized for the serum detection of target antigen by SPR method.

Comparison of Fluidic and Non-Fluidic Surface Plasmon Resonance Biosensor Variants for Angular and Intensity Modulation Measurements

Fluidic and non-fluidic surface plasmon resonance measurements were realized for the same type of sensory layer and using the same mouse IgG antibody and anti-mouse IgG antibody biomolecular system. A comparison of the thicknesses of the anti-mouse IgG antibody layers bound to the ligand at increasing analyte concentrations ranging from 0.0 μg mL-1 to 5.0 μg mL-1 in the non-fluidic and the fluidic variant showed that the thickness of the bound anti-mouse antibody layers in the fluidic variant was approximately 1.5-3 times larger than in the non-fluidic variant. The greater thicknesses of the deposited layers were also reflected in the larger increment of the resonant angle in the fluidic variant compared to the non-fluidic variant in the considered range of analyte concentrations. The choice between fluidic and non-fluidic surface plasmon resonance biosensors may be justified by the availability of analyte volume and the intended modulation technique. When working with limited analyte, non-fluidic biosensors with intensity modulation are more advantageous. For larger analyte quantities, fluidic biosensors with angular modulation are recommended, primarily due to their slightly higher sensitivity in this measurement mode.

Field-flow fractionation - an excellent tool for fractionation, isolation and/or purification of biomacromolecules

Field-flow fractionation (FFF) with its several variants, has developed into a mature methodology. The scope of the FFF investigations has expanded, covering both a wide range of basic studies and especially a wide range of analytical applications. Special attention of this review is given to the achievements of FFF with reference to recent applications in the fractionation, isolation, and purification of biomacromolecules, and from which especially those of (in alphabetical order) bacteria, cells, extracellular vesicles, liposomes, lipoproteins, nucleic acids, and viruses and virus-like particles. In evaluating the major approaches and trends demonstrated since 2012, the most significant biomacromolecule applications are compiled in tables. It is also evident that asymmetrical flow field-flow fractionation is by far the most dominant technique in the studies. The industry has also shown current interest in FFF and adopted it in some sophisticated fields. FFF, in combination with appropriate detectors, handles biomacromolecules in open channel in a gentle way due to the lack of shear forces and unwanted interactions caused by the stationary phase present in chromatography. In addition, in isolation and purification of biomacromolecules quite high yields can be achieved under optimal conditions.

Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.