This PDF file contains the front matter associated with SPIE Proceedings Volume 12858, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Vitamin C, or ascorbic acid, is a vital nutrient with significant implications for human health. Accurate and rapid detection of vitamin C concentrations in various samples holds immense importance in medical, pharmaceutical, and food industries. In this study, we introduce a novel approach utilizing an etched fiber-based plasmon sensor for sensitive and selective detection of vitamin C. The biosensor employs a gold-coated optical fiber with a precisely etched region, enabling the excitation of surface plasmon polaritons (SPPs). The interaction between SPPs and the vitamin C analyte induces changes in the refractive index near the fiber surface, consequently causing shifts in the resonance wavelength of the plasmonic mode. By monitoring these wavelength shifts, the concentration of vitamin C in the sample can be accurately determined. This research presents a promising platform for enhanced detection of vitamin C, offering potential applications in various fields.

Understanding and accurately analyzing the mechanical properties of microelectromechanical systems (MEMS) is essential for assessing their device functionality and performance. Precisely measuring the dynamic properties of a quartz tuning fork (QTF), for instance, can significantly enhance the imaging resolution of QTF-based scanning probe microscopy systems. Current methods, such as analytical and numerical approaches, have limitations when it comes to providing accurate measurements. To overcome these limitations, we proposed an experimental approach that combines stroboscopic and sampling Moiré (SM) techniques. Our method focuses on investigating the in-plane vibration behavior of a QTF and utilizes the obtained results to measure its mechanical parameters. To achieve this, we synchronize nanometer-scale light pulses, generated using a custom-designed stroboscope, with the QTF’s excitation voltage, effectively freezing the vibrations. These vibrations are then observed using a standard CCD camera. Subsequently, SM analysis is employed to extract the surface vibration profile, facilitating the measurement of dynamic properties. This technique has the potential to analyze various micro-devices that are compatible with the sample preparation process.

We introduce an infrared metasurface sensor based on plasmonic surface-enhanced infrared absorption spectroscopy combined with immunoassay, which detects alpha-synuclein, an early structural biomarker protein for neurodegenerative diseases with clinical specificity and identifies its different structural species using their unique spectroscopic signals. Unprecedentedly, we augmented the sensor with a Deep Neural Network, enabling quantitative differentiation of alpha-synuclein aggregates. Capable of multiplexing and retrieving aggregate signatures from complex biomatrix, our sensor shows promise for neurodegenerative disease diagnosis, disease progression monitoring, and drug efficacy assessment.

The potential advantages of infrared spectroscopic imaging for examination of cells and tissue biopsies for cancer histopathology is high, however there are fundamental limitations of FTIR that must first be addressed. One limitation is that Infrared spectroscopy lacks the sensitivity to detect biomarkers of disease directly. With cancer being one of the leading causes of death and its increasing prevalence, it is important to develop tools that can rapidly screen and enable rapid and simultaneous fingerprinting of biologic content and metabolic state. To address these limitations, probed Infrared spectroscopy is being explored. We report the successful synthesis, characterization, and application of metal carbonyl loaded nanoparticle probes for the detection of breast cancer biomarkers.

Water pollution, particularly from hazardous substances like heavy metal ions, poses a serious threat to both human health and the environment. The conventional methods used to measure these pollutants in water are not only expensive and time-consuming but also require extensive sample preparation. Addressing this challenge, we propose an optical approach that utilizes the full scattering profile, focusing on the iso-pathlength (IPL) point. The IPL point remains constant for different scattering coefficients, with absorption affecting only its intensity, not its position. This paper demonstrate the effectiveness of this approach detecting FeCl2 and intralipid in concentrations of 70-100 and 20-30 ppm, respectively. These findings highlight the IPL point as an intrinsic calibration parameter, offering an efficient means to differentiate water contamination. The method is not only precise and versatile but also emerges as a preferred choice for real-time water monitoring applications.

Optical super-resolution microscopy has revolutionized imaging in the lateral axis, enabling nanoscale structure visualization with unprecedented detail. However, achieving high axial resolution along the z-axis remains challenging. In this study, nanoscale fluctuation-enhanced axial localization microscopy addresses this issue by incorporating metallic structures, specifically reflective optical devices, into dynamic speckle illumination microscopy. By controlling light waves within the fluidic chip, these metallic devices enable super-resolution to be achieved not only in the lateral direction but also along the z-axis, all in a cost-effective manner. Experimental investigation using 100-nm fluorescent beads and the U-87 MG cell membrane demonstrates axial-resolving performance of fluctuation-enhanced imaging compared to conventional methods. The application of an optical fluctuation-based reconstruction algorithm further allows the extraction of 4-fold enhanced axial information over diffraction-limited system.

Liposomes, self-assembled lipid-based nanoparticles, have gained significant attention due to their versatility and potential applications in various biomedical fields. They serve as promising platforms for targeted drug delivery, imaging, and therapeutics. Among the various types of liposomes, radiolabeled liposomes have attracted considerable interest due to their unique capabilities in both therapy and imaging. In therapy, radiolabeled liposomes can effectively transport therapeutic radioactive agents directly to disease sites, allowing for precise and localized treatment. In imaging, radiolabeling enables non-invasive visualization and tracking of liposomes, providing valuable diagnostic information. In this study, we present a technique for surface radiolabeling of liposomes, achieved by introducing a chelating agent onto the liposome surface and optimizing radiolabeling conditions for desired radionuclides. Importantly, our technique allows for the radiolabeling process to be conducted after the liposomes have been formulated according to the desired composition, enabling seamless integration into biomedical research and clinical practice. Our research investigates optimal radiolabeling conditions for different isotopes, ensuring stability and high efficiency. Purification and characterization of the resulting radiolabeled liposomes validate their quality and stability. The findings of this study offer valuable insights for the future advancement and application of radiolabeled liposomes in biomedical research and clinical practice, holding promise for improved therapies and diagnostics.

Gold nanoparticles (GNPs) have garnered significant attention in biomedical applications, particularly as versatile platforms for drug delivery and targeted therapy. The conjugation of GNPs with antibodies offers a promising strategy to enhance their specificity and efficacy in various therapeutic approaches. In this study, we focus on synthesizing different types of GNPs conjugated with antibodies and investigate the influence of various synthesis methods on nanoparticle characterization. The results demonstrated that different synthesis methods lead to different degrees of antibody conjugation on the GNP surface and to varied efficiency on biosystems. This work has the potential to outline design principles that could positively affect the development of targeted nanotherapeutics for various biomedical applications.

Nanophotonic techniques for diagnosis of a physiological tissue state are useful due to their noninvasive nature. Yet, light reflectance from a tissue is determined by the medium optical properties, absorption and scattering. Therefore, evaluating physiological parameters that correlate with absorption exclusively requires calibration of the scattering. While finding pulse rate is possible in a single wavelength, other parameters, such as oxygen saturation, require more than one light source and ratiometric measurements. As a result, the differences in the optical pathlength of the different wavelengths produce an inherent error. We have previously discovered the iso-path length (IPL) point, a specific position around a cylindrical media where the light intensity is not affected by the scattering. It was found by measuring the full scattering profile (FSP), meaning the angular distribution of light intensity of cylindrical tissues. Therefore, when measuring in this point, the absorption can be isolated from the scattering. This allows extracting physiological parameters such as oxygen saturation from a single wavelength measurement. In this research we designed an optic biosensor for measuring the reemitted light from the tissue, constructed with a single light source and several photodetectors, as one of them is in the IP point’s location. We conducted several experiments for measuring the oxygen saturation, heart rate (HR) and respiratory rate (RR) in ordinary conditions. In addition, we conducted experiments in a hypoxic chamber for simulating extreme conditions of lack of oxygen. With our biosensor that utilizes the IPL point, we strive to continue experimenting and measuring other parameters as well.

In today's medical world, endoscopy is one of the most common methods for assessing a patient's health status, yet in most cases, endoscopy is not sufficient and usually requires other examinations as well. It is widely known that healthy, and diseased tissues possess different optical properties like scattering and absorption. By finding the changes in those optical properties it's possible to determine the tissue status by endoscopy only. This poster suggests an alternative self-calibrated endoscopy examination for finding these properties and quantitatively assessing the tissue. Implementing the physical phenomenon called the iso pathlength (IPL) point, makes it possible to extract the tissue absorption property since it simplifies the problem into an easily solvable first-order problem. The phenomenon claims the existence of physical positions on the surface tissue, in which the light reflected from, isn't affected by the tissue's scattering. The work proves experimentally the existence of the IPL point for hollow cylindrical tissue structures. Three hollow cylindrical phantoms, with different scattering coefficients and negligible absorption properties, were illuminated, and by extracting all the reflected intensities of the different phantoms as a function of length or angle, a cross point between all the variables was shown. This spot proves the existence of points that aren't affected by the scattering profile.

Chemotherapy is the gold standard for cancer treatment. However, the specific and safe delivery of chemotherapies to cancer cells remains a great challenge. Gold nanoparticles (GNPs) offer a promising solution as carriers for chemotherapy due to their biocompatibility and distinctive physicochemical properties that facilitate precise drug binding and enhanced tumor penetration through the enhanced permeability and retention effect. Here, we have designed GNPs bound to chemotherapies together with glucose coating and studied their cancer cell killing efficacy in a head and neck squamous cell carcinoma cell line. We found that the GNPs bound to chemotherapy had a higher cancer cell killing efficacy as compared to controls, as well as a bystander effect. This GNP-based platform holds promise, for advancing chemotherapy-based cancer treatments.

Cisplatin (CP) is the primary standard treatment for bladder cancer. Nevertheless, CP has side effects, particularly nephrotoxicity. This limits the treatment of a notable portion of advanced bladder cancer patients with cisplatin. We have developed gold nanoparticles that conjugate CP (CP-AuNPs) for safer delivery to tumors. Here, we investigated the biodistribution of the CP-AuNP conjugates in a mouse model of bladder cancer, to characterize the distinct role of CPAuNP in delivering and releasing CP in tumor and tissues. Effect of the CP-AuNPs on weight and kidney was also investigated. This study can provide insights into the potential safety of CP-AuNP for bladder cancer treatment.

Green chemistry of fluorescent carbon nanoparticles (CNPs) from common sources such as leaves has gained significant interest due to their strong optical properties, and high photo stability. This paper highlights a microwave-assisted approach for the synthesis of carbon nanoparticles from the leaf extract of two plants Syzygium Cumini and Ocimum tenuiflorum, (commonly known as Jamun and Tulsi, so addressed here as JNPs and TNPs respectively), possessing various natural medicinal benefits, being addressed here as JNPs and TNPs. They exhibited an average size of 70 nm and emitted red fluorescence when exposed to ultraviolet light. The absorption spectra of both were recorded, alongside investigating functional groups using Fourier transform infrared spectroscopy. The average crystallite size for TNPs and JNPs is 23.63 nm and 28.35 nm were recorded using X-ray diffraction (XRD). Due to their excellent fluorescent property, they can be potentially used for drug delivery and therapy applications, thereby replacing the usage of conventional organic fluorescent molecules/dyes.