Sensitive Detection Technology Research Articles

High-throughput methylation sequencing reveals novel biomarkers for the early detection of renal cell carcinoma

PurposeRenal cell carcinoma (RCC) is a common malignancy, with patients frequently diagnosed at an advanced stage due to the absence of sufficiently sensitive detection technologies, significantly compromising patient survival and quality of life. Advances in cell-free DNA (cfDNA) methylation profiling using liquid biopsies offer a promising non-invasive diagnostic option, but robust biomarkers for early detection are current not available. This study aimed to identify methylation biomarkers for RCC and establish a DNA methylation signature-based prognostic model for this disease.MethodsHigh-throughput methylation sequencing was performed on peripheral blood samples obtained from 49 primarily Stage I RCC patients and 44 healthy controls. Comparative analysis and Least Absolute Shrinkage and Selection Operator (LASSO) regression methods were employed to identify RCC methylation signatures.Subsequently, methylation markers-based diagnostic and prognostic models for RCC were independently trained and validated using random forest and Cox regression methodologies, respectively.ResultsComparative analysis revealed 864 differentially methylated CpG islands (DMCGIs), 96.3% of which were hypermethylated. Using a training set from The Cancer Genome Atlas (TCGA) dataset of 443 early-stage RCC tumors and matched normal tissues, we applied LASSO regression and identified 23 methylation signatures. We then constructed a random forest-based diagnostic model for early-stage RCC and validated the model using two independent datasets: a TCGA set of 460 RCC tumors and controls, and a blood sample set from our study of 15 RCC cases and 29 healthy controls. For Stage I RCC tissue, the model showed excellent discrimination (AUC-ROC: 0.999, sensitivity: 98.5%, specificity: 100%). Blood sample validation also yielded commendable results (AUC-ROC: 0.852, sensitivity: 73.9%, specificity: 89.7%). Further analysis using Cox regression identified 7 of the 23 DMCGIs as prognostic markers for RCC, allowing the development of a prognostic model with strong predictive power for 1-, 3-, and 5-year survival (AUC-ROC > 0.7).ConclusionsOur findings highlight the critical role of hypermethylation in RCC etiology and progression, and present these identified biomarkers as promising candidates for diagnostic and prognostic applications.

Resilient sustainable current and emerging technologies for foodborne pathogen detection.

Foodborne pathogens such as Salmonella, Escherichia coli and Listeria pose significant risks to human health. The World Health Organization estimates that 2.2 million deaths per year are directly caused by foodborne and waterborne bacterial diseases worldwide. Accordingly, detecting pathogens in food is essential to ensure that our food is safe. This review explores the critical role of novel technologies in enhancing food safety practices whilst delving into adopting and integrating innovative, resilient and sustainable approaches in the food supply chain. Further, applying novel, emerging advanced analytical techniques such as Raman spectroscopy and nanotechnology based biosensors in food contamination detection is discussed. These advanced technologies show the promise of real-time monitoring, traceability, and predictive analytics to identify and mitigate potential hazards before they reach consumers. They can provide rapid and accurate results and ensure the integrity of food products. Furthermore, the herein-highlighted synergistic integration of these technologies offers a promising path toward a safer and more transparent food system, thereby addressing the challenges of today's globalised food market and laying the platform for developing multimodal technologies for affordable, sensitive and rapid pathogen detection along the different stages of the food chain, from "farm to fork".

PhOxi-seq Detects Enzyme-Dependent m2G in Multiple RNA Types.

In recent years, RNA-modifying enzymes have gained significant attention due to their impact on critical RNA-based processes and, consequently, human pathology. However, identifying sites of modifications throughout the transcriptome remains challenging largely due to the lack of accurate and sensitive detection technologies. Recently, we described PhOxi-seq as a method capable of confirming known sites of m2G within abundant classes of RNA, namely, purified rRNA and purified tRNA. Here, we further explore the selectivity of PhOxi-seq and describe an optimized PhOxi-seq workflow, coupled to a novel bioinformatic pipeline, that is capable of detecting enzyme-dependent m2G sites throughout the transcriptome. In this way, we generated a database of potential THUMPD3-dependent m2G sites in multiple RNA classes within a human cancer cell line and further identify potential non-THUMPD3 controlled m2G sites. These potential sites should serve as the basis for further confirmation studies for m2G within the human transcriptome.

Defective UIO66 metal-organic framework nanoparticles assisted by cascade isothermal amplification technology for the detection of aflatoxin B1.

Aflatoxin B1 (AFB1) exhibits significant toxicity and pose a serious threat to food safety, environmental hygiene, and public health even in trace amounts. Hence, the development of a rapid, accurate, and sensitive detection technology has become a pivotal aspect of ensuring control standards. In this study, we introduce the UIO66 and two defective dichloroacetic acid@UIO66 (DCA@UIO66, DU) metal-organic framework nanoparticles, named DU1 and DU2, characterized by different defect levels. It is noteworthy that DU1 exhibits superior DNA sensing capability compared to UIO66 and DU2. With a fluorescence quenching efficiency of 92.66% and a recovery efficiency of 1256.75%, DU1 demonstrates the substantial potential in the detection field. Furthermore, we employ cascade isothermal amplification to assist DU1-mediated fluorescence sensors in detecting AFB1. AFB1 is efficiently identified through an aptamer competition process facilitated by magnetic nanoparticles, which initiates the exponential amplification triggered rolling circle amplification reaction, and converts trace amounts of toxin signal into a large number of long single-stranded DNA molecules. Upon recognition of the amplification product by the fluorescent probe on DU1, a more stable double-stranded DNA is formed and leaves the surface of DU1, leading to a significant change in fluorescence intensity. This method exhibits acceptable sensitivity, with a detection limit of 0.09pgmL-1 and a wide detection range spanning from 0.2pgmL-1 to 20pgmL-1. Additionally, this assay exhibits satisfactory specificity and high accuracy in practical sample applications. Our proposed method offers a solid theoretical framework and technical backing, thereby facilitating the establishment of a new generation of mycotoxin detection standards.

Sustainable Biopolymer-Based Electrochemical Sensors for Trace Heavy Metal Determination in Water: A Comprehensive Review

The growing concern over heavy metal contamination in environmental and industrial settings has intensified the need for sensitive, selective, and cost-effective detection technologies. Electrochemical sensors, due to their high sensitivity, rapid response, and portability, have emerged as promising tools for detecting heavy metals. Recent years have seen significant progress in utilizing biopolymer-based materials to enhance the performance of these sensors. Biopolymers, derived from renewable raw materials, have garnered considerable interest in both science and industry. These biopolymer-based composites are increasingly recognized as superior alternatives to conventional non-biodegradable materials because of their ability to degrade through environmental exposure. This review provides a comprehensive overview of recent advancements in biopolymer-based electrochemical sensors for heavy metal detection. It discusses various types of biopolymers and bio-sourced polymers, their extraction methods, and chemical properties. Additionally, it highlights the state of the art in applying biopolymers to electrochemical sensor development for heavy metal detection, synthesizing recent advances and offering insights into design principles, fabrication strategies, and analytical performance. This review underscores the potential of biopolymer-based sensors as cost-effective, eco-friendly, and efficient tools for addressing the pressing issue of heavy metal contamination in water and discusses their advantages and limitations. It also outlines future research directions to further enhance the performance and applicability of these sensors.

Development of a colloidal gold immunochromatographic test strip for detecting the smooth Brucella

SummaryBrucellosis, caused by Gram-negative Brucella, spreads in human and animal populations through contact with infected animals and products. Developing a rapid and sensitive detection technology for pathogen is crucial to reduce the risk of this disease transmitting between animal populations and to humans. We produced a monoclonal antibody LPS-6B5, which shows high affinity to LPS and limited cross-reactivity with other bacteria. Based on LPS-6B5, a colloidal gold immunochromatographic assay (GICA) was developed which demonstrates high sensitivity and specificity in detecting cultured B. melitensis, B. abortus and B. suis. The Gold Immunochromatographic Assay (GICA) strips exhibited the most sensitive detection limits, with a value of 7.8125 × 105 CFU/mL for Brucella melitensis, surpassing the sensitivity levels observed for Brucella abortus and Brucella suis. It is also suitable for clinical and field samples, providing a cost-effective and user-friendly alternative to traditional methods.

Research on Spatial Localization Method of Magnetic Nanoparticle Samples Based on Second Harmonic Waves

Existing magnetic tracer detection systems primarily rely on fundamental wave signal acquisition using non-differential sensor configurations. These sensors are highly susceptible to external interference and lack tomographic localization capabilities, hindering their clinical application. To address these limitations, this paper presents a novel method for achieving the deep spatial localization of tracers. The method exploits second harmonic signal detection at non-zero field points. By considering the combined nonlinear characteristics of the coil’s axial spatial magnetic field distribution and the Langevin function, a correlation model linking the signal peak and bias field is established. This model enables the determination of the tracer’s precise spatial location. Building on this framework, a handheld device for localizing magnetic nanoparticle tracers was developed. The device harnesses the second harmonic response generated by coupling an AC excitation field with a DC bias field. Our findings demonstrate that under conditions of reduced coil turns and weak excitation fields, the DC bias field exhibits exclusive dependence on the axial distance of the detection point, independent of particle concentration. This implies that the saturated DC bias field corresponding to the second harmonic signal can be used to determine the magnetic nanoparticle sample detection depth. The experimental results validated the method’s high accuracy, with axial detection distance and concentration reduction errors of only 4.8% and 4.1%, respectively. This research paves the way for handheld probes capable of tomographic tracer detection, offering a novel approach for advancing magnetically sensitive biomedical detection technologies.

Development of plate-type and tubular chemiluminescence immunoassay against African swine fever virus p72

African swine fever (ASF) is a highly contagious and fatal viral disease that has caused huge economic losses to the pig and related industries worldwide. At present, rapid, accurate, and sensitive laboratory detection technologies are important means of preventing and controlling ASF. However, because attenuated strains of African swine fever virus (ASFV) are constantly emerging, an ASFV antibody could be used more effectively to investigate the virus and control the disease on pig farms. The isolation of ASFV-specific antibodies is also essential for the diagnosis of ASF. Therefore, in this study, we developed two chemiluminescence immunoassays (CLIAs) to detect antibodies directed against ASFV p72: a traditional plate-type blocking CLIA (p72-CLIA) and an automatic tubular competitive CLIA based on magnetic particles (p72-MPCLIA). We compared the diagnostic performance of these two methods to provide a feasible new method for the effective prevention and control of ASF and the purification of ASFV. The cut-off value, diagnostic sensitivity (Dsn), and diagnostic specificity (Dsp) of p72-CLIA were 40%, 100%, and 99.6%, respectively, in known background serum, whereas those of p72-MPCLIA were 36%, 100%, and 99.6%, respectively. Thus, both methods show good Dsn, Dsp, and repeatability. However, when analytical sensitivity was evaluated, p72-MPCLIA was more sensitive than p72-CLIA or a commercial enzyme-linked immunosorbent assay. More importantly, p72-MPCLIA reduced the detection time to 15 min and allowed fully automated detection. In summary, p72-MPCLIA showed superior diagnostic performance and offered a new tool for detecting ASFV infections in the future.Key points• Two chemiluminescence immunoassay (plate-type CLIA and tubular CLIA) methods based on p72 monoclonal antibody (mAb) were developed to detect ASFV antibody.• Both methods show good diagnostic performance (Dsn (100%), Dsp (99.6%), and good repeatability), and p72-MPCLIA detects antibodies against ASFV p72 with high efficiency in just 15 min.

SATCAS: A CRISPR/Cas13a-based simultaneous amplification and testing platform for one-pot RNA detection and SNPs distinguish in clinical diagnosis

The clinical diagnosis of pathogen infectious diseases increasingly requires sensitive and rapid RNA detection technologies. The RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)/Cas13a system has shown immense potential in molecular diagnostics due to its trans-cleavage activity. However, most Cas13a-based detection methods require an amplicon transcription step, and the multi-step open-tube operations are prone to contamination, limiting their widespread application. Here, we propose an ultrasensitive (single-copy range, ∼aM) and rapid (within 40 min) isothermal one-pot RNA detection platform, termed SATCAS (Simultaneous Amplification and Testing platform based on Cas13a). This method effectively distinguishes viable bacteria (0%–100%) under constant total bacterial conditions, demonstrating its robustness and universality. SATCAS excels in identifying single nucleotide polymorphisms (SNPs), particularly detecting 0.5% drug-resistant mutations. We validated SATCAS by detecting infections in biological samples from 68 HBV, 23 EBV, and 48 SARS-CoV-2 patients, achieving 100% sensitivity, 92.86% specificity, and 97.06% accuracy in HBV infection testing. We anticipate that SATCAS has broad application potential in the early diagnosis, subtyping, drug resistance detection, and point-of-care monitoring of pathogen infectious diseases.

Triple quenching effect of nanozyme catalyzed precipitation combined with enzyme-free amplification for photoelectrochemical biosensing of circulating tumor DNA

In this work, a new photoelectrochemical (PEC) biosensor based on triple quenching effect of nanozyme catalyzed precipitation to PEC signal of MgIn2S4 was constructed for ultrasensitive detection of circulating tumor DNA (ctDNA). Enzyme-free amplification technology was used to convert target ctDNA into a large number of product chains (PC) to improve the detection sensitivity. Co3O4 nanozyme with excellent peroxidase (POD)-like activity was introduced to the surface of MgIn2S4 by PC. Co3O4 could oxidize chromogenic agent 3-Amino-9-ethylcarbazole (AEC) to produce red insoluble precipitation in the presence of H2O2, resulting in the PEC signal “off” of MgIn2S4 to achieve ultrasensitive detection of ctDNA. In particular, Co3O4 nanozyme showed three synergistic quenching effects on PEC signal of MgIn2S4, which contributed greatly to improving the detection sensitivity. Firstly, the light absorption range of Co3O4 could reach 1000 nm, and compete with MgIn2S4 for light absorption. Secondly, the produced red precipitation belonged to the insulating material and had large electrochemical impedance, which hindered the transmission of photogenerated carriers. Thirdly, the precipitation also prevented the electron donor ascorbic acid (AA) from transferring electrons to MgIn2S4. This biosensor provided a promising sensitive PEC detection technology for ctDNA, and further broadened the application of nanozymes in the field of PEC analysis.

Trends and frontiers in signal amplification for aptamer-based tumor detection: A bibliometric analysis.

Malignant tumors are one of the leading causes of death worldwide, imposing a substantial economic and social burden. Early detection is the key to improving cure rates and reducing mortality rates, which requires the development of sensitive early detection technologies. Signal amplification techniques play a crucial role in aptamer-based early detection of tumors and are increasingly garnering attention from researchers. To investigate the current research status, developmental trajectories, and hotspots in signal amplification for aptamer-based tumor detection through bibliometric analysis. English publications pertaining to signal amplification in aptamer-based tumor detection were retrieved from the Web of Science Core Collection database. VOSviewer and CiteSpace software were employed to analyze various information within this field, including countries, institutions, authors, co-cited authors, journals, co-cited journals, cited references, and keywords. A total of 757 publications were included in this study. China accounted for 85.47% of all publications, with Nanjing University (China) emerging as the institution with the highest publication output. The most influential authors and journals were Hasanzadeh M. from Iran and "Biosensors and Bioelectronics", respectively. Exosomes and carcinoembryonic antigen (CEA) stood out as the most researched tumor-related molecules. Currently, the predominant signal amplification technique, nanomaterial, and signal transduction method were identified as hybridization chain reactions, gold nanoparticles, and electrochemical methods, respectively. Over the past 3 years, exosomes, CEA, electrochemical biosensors, and nanosheets have emerged as research hotspots, exhibiting a robust burst of intensity. This study is the first bibliometric analysis of literature on signal amplification in aptamer-based tumor detection and elucidates the current status, hotspots, and prospective research directions within this realm. Additionally, it provides an important reference for researchers.

Facile Preparation of TiO2NTs/Au@MOF Nanocomposites for High-Sensitivity SERS Sensing of Gaseous VOC.

Surface-enhanced Raman spectroscopy (SERS) is a promising and highly sensitive molecular fingerprint detection technology. However, the development of SERS nanocomposites that are label-free, highly sensitive, selective, stable, and reusable for gaseous volatile organic compounds (VOCs) detection remains a challenge. Here, we report a novel TiO2NTs/AuNPs@ZIF-8 nanocomposite for the ultrasensitive SERS detection of VOCs. The three-dimensional TiO2 nanotube structure with a large specific surface area provides abundant sites for the loading of Au NPs, which possess excellent local surface plasmon resonance (LSPR) effects, further leading to the formation of a large number of SERS active hotspots. The externally wrapped porous MOF structure adsorbs more gaseous VOC molecules onto the noble metal surface. Under the synergistic mechanism of physical and chemical enhancement, a better SERS enhancement effect can be achieved. By optimizing experimental conditions, the SERS detection limit for acetophenone, a common exhaled VOC, is as low as 10-11 M. And the relative standard deviation of SERS signal intensity from different points on the same nanocomposite surface is 4.7%. The acetophenone gas achieves a 1 min response and the signal reaches stability in 4 min. Under UV irradiation, the surface-adsorbed acetophenone can be completely degraded within 40 min. The experimental results demonstrate that this nanocomposite has good detection sensitivity, repeatability, selectivity, response speed, and reusability, making it a promising sensor for gaseous VOCs.

Emerging Technologies for Sensitive Detection of Organophosphate Pesticides: A Review

Abstract: The use of organophosphate pesticides (OPPs) in agricultural practices improves crop yield and controls pests, but their indiscriminate use and persistence in the environment pose significant health risks. Therefore, it has become increasingly important to develop reliable and efficient detection methods for OPPs to ensure food safety and monitor their presence. In recent years, OPP detection methods have undergone significant advancements. Sensors such as colorimetric, fluorescence, electrochemical, and impedometric offer several advantages over traditional methods, such as high sensitivity, selectivity, and portability. The purpose of this review paper is to provide an overview of recent developments in OPP detection methods. The paper discusses the different types of sensors that are available for the detection of OPPs, as well as their advantages and disadvantages. Many electrochemical methods have been employed to investigate OPP detection, including voltammetry, impedance spectroscopy, and amperometry. The integration of nanomaterials, such as carbon nanotubes, graphene, and metal nanoparticles, has significantly enhanced the performance of electrochemical sensors by providing high surface area, enhanced electron transfer, and specific analyte interactions. Furthermore, the review discusses the utilization of biomolecules, such as enzymes and aptamers, as recognition elements in sensor platforms for selective and sensitive OPP detection. The incorporation of these biomolecules offers high specificity and enables real-time monitoring of OPP residues in food samples and environmental matrices. It emphasizes the importance of continued research and development to optimize detection methods, improve sensor performance, and make these technologies more widely accessible for effective monitoring and control of OPP contamination in various domains.

Screen-Printed Bimetallic Cobalt-Manganese Metal-Organic Framework Electrodes for Electrochemical Detection of Dichlorvos

Organophosphate pesticides are extremely hazardous to human health and the environment, discerning the development of sensitive and selective detection technologies. In this paper, we describe a novel technique for detecting dichlorvos (DDVP), an organophosphate pesticide, using a modified screen-printed electrode (SPE). The metal-organic framework (MOF) containing cobalt and manganese ions in an equimolar ratio was synthesised using a solvothermal method. The synthesized material was characterized using various techniques: FE-SEM, XRD, XPS, BET, Raman spectroscopy, and FTIR. The electro-catalytic behavior of the material was studied utilizing electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The insightful behaviour of the material towards dichlorvos had been investigated through differential pulse voltammetry (DPV) in the concentration range of 1–10 nM with a detection limit of 0.645 nM. Furthermore, we tested our proposed sensor’s selectivity and applicability using real-world samples. Our findings provide insight into the development of highly sensitive and selective detection systems for organophosphate pesticides, which might have implications for environmental monitoring and public health.

Recent advances of molecular imprinting technology for the separation and recognition of complex biological sample systems

Given continuous improvements in industrial production and living standards, the analysis and detection of complex biological sample systems has become increasingly important. Common complex biological samples include blood, serum, saliva, and urine. At present, the main methods used to separate and recognize target analytes in complex biological systems are electrophoresis, spectroscopy, and chromatography. However, because biological samples consist of complex components, they suffer from the matrix effect, which seriously affects the accuracy, sensitivity, and reliability of the selected separation analysis technique. In addition to the matrix effect, the detection of trace components is challenging because the content of the analyte in the sample is usually very low. Moreover, reasonable strategies for sample enrichment and signal amplification for easy analysis are lacking. In response to the various issues described above, researchers have focused their attention on immuno-affinity technology with the aim of achieving efficient sample separation based on the specific recognition effect between antigens and antibodies. Following a long period of development, this technology is now widely used in fields such as disease diagnosis, bioimaging, food testing, and recombinant protein purification. Common immuno-affinity technologies include solid-phase extraction (SPE) magnetic beads, affinity chromatography columns, and enzyme linked immunosorbent assay (ELISA) kits. Immuno-affinity techniques can successfully reduce or eliminate the matrix effect; however, their applications are limited by a number of disadvantages, such as high costs, tedious fabrication procedures, harsh operating conditions, and ligand leakage. Thus, developing an effective and reliable method that can address the matrix effect remains a challenging endeavor. Similar to the interactions between antigens and antibodies as well as enzymes and substrates, biomimetic molecularly imprinted polymers (MIPs) exhibit high specificity and affinity. Furthermore, compared with many other biomacromolecules such as antigens and aptamers, MIPs demonstrate higher stability, lower cost, and easier fabrication strategies, all of which are advantageous to their application. Therefore, molecular imprinting technology (MIT) is frequently used in SPE, chromatographic separation, and many other fields. With the development of MIT, researchers have engineered different types of imprinting strategies that can specifically extract the target analyte in complex biological samples while simultaneously avoiding the matrix effect. Some traditional separation technologies based on MIP technology have also been studied in depth; the most common of these technologies include stationary phases used for chromatography and adsorbents for SPE. Analytical methods that combine MIT with highly sensitive detection technologies have received wide interest in fields such as disease diagnosis and bioimaging. In this review, we highlight the new MIP strategies developed in recent years, and describe the applications of MIT-based separation analysis methods in fields including chromatographic separation, SPE, diagnosis, bioimaging, and proteomics. The drawbacks of these techniques as well as their future development prospects are also discussed.

Ultra-sensitive and rapid detection of Salmonella enterica and Staphylococcus aureus to single-cell level by aptamer-functionalized carbon nanotube field-effect transistor biosensors

Foodborne diseases caused by Salmonella enterica (S. enterica) and Staphylococcus aureus (S. aureus) significantly impact public health, underscoring the imperative for highly sensitive, rapid, and accurate detection technologies to ensure food safety and prevent human diseases. Nanomaterials hold great promise in the development of high-sensitivity transistor biosensors. In this work, field-effect transistor (FET) comprising high-purity carbon nanotubes (CNTs) were fabricated and modified with corresponding nucleic acid aptamers for the high-affinity and selective capture of S. enterica and S. aureus. The aptamer-functionalized CNT-FET biosensor demonstrated ultra-sensitive and rapid detection of these foodborne pathogens. Experimental results indicated that the biosensor could detect S. enterica at a limit of detection (LOD) as low as 1 CFU in PBS buffer, and S. aureus at an LOD of 1.2 CFUs, achieving single-cell level detection accuracy with exceptional specificity. The biosensor exhibited a rapid response time, completing single detections within 200 s. Even in the presence of interference from six complex food matrices, the biosensor maintained its ultra-sensitive (3.1 CFUs) and rapid response (within 200 s) characteristics for both pathogens. The developed aptamer-functionalized CNT-FET biosensor demonstrates a capability for low-cost, ultra-sensitive, label-free, and rapid detection of low-abundance S. enterica and S. aureus in both buffer solutions and complex environments. This innovation holds significant potential for applying this detection technology to on-site rapid testing scenarios, offering a promising solution to the pressing need for efficient and reliable pathogen monitoring in various settings.

RNA-Based Sensor Systems for Affordable Diagnostics in the Age of Pandemics.

In the era of the COVID-19 pandemic, the significance of point-of-care (POC) diagnostic tools has become increasingly vital, driven by the need for quick and precise virus identification. RNA-based sensors, particularly toehold sensors, have emerged as promising candidates for POC detection systems due to their selectivity and sensitivity. Toehold sensors operate by employing an RNA switch that changes the conformation when it binds to a target RNA molecule, resulting in a detectable signal. This review focuses on the development and deployment of RNA-based sensors for POC viral RNA detection with a particular emphasis on toehold sensors. The benefits and limits of toehold sensors are explored, and obstacles and future directions for improving their performance within POC detection systems are presented. The use of RNA-based sensors as a technology for rapid and sensitive detection of viral RNA holds great potential for effectively managing (dealing/coping) with present and future pandemics in resource-constrained settings.

Hybrid Materials From Peptide Nanofibrils and Magnetic Beads to Concentrate and Isolate Virus Particles

AbstractPeptide nanofibrils (PNFs) are considered a novel and highly efficient class of retroviral transduction enhancers due to their ability to efficiently bind virus particles and promote their attachment to the membrane of target cells. In this study, the virus‐binding properties of enhancing factor C (EF‐C) PNFs are used to develop a method for concentrating and isolating HIV‐1 particles without the need for centrifugation. Upon incubation in a virus‐laden sample, PNF‐coated magnetic beads facilitate magnetic separation, effectively depleting virus particles from the solution and consequently reducing its infectious nature. Remarkably, the isolated virus particles maintain their infectivity and exhibit an enhanced ability to infect target cells due to the complexation with EF‐C PNFs. This enhancement is pivotal for further virus propagation in cell cultures or detailed analysis. The presented method addresses the urgent need for more rapid, sensitive detection, and purification technologies for viral agents. It provides a tool to efficiently capture, isolate, and concentrate HIV‐1 particles. This may significantly improve the sensitivity of existing diagnostic tools and analytical tests.

Abstract B045: In vivo ovarian cancer detection using folate receptor-α targeted iron oxide nanoparticles

Abstract Ovarian cancer is the second most common and most deadly gynecological cancer in women. Early and accurate detection is crucial in improving survival rate and quality of life of patients. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used in a variety of cancer detection/imaging applications, including Magnetic Resonant Imaging (MRI), Magnetic Particle Imaging (MPI) as well as Superparamagnetic Relaxometry (SPMR) detection currently being developed in-house. SPMR is a highly sensitive detection technology that can differentiate the magnetic signature of nanoparticles bound to tumor cells from unbound nanoparticles (NP). Folate receptor alpha (FRα) is a folate transporter overexpressed in approximately 90% of ovarian cancer, which makes it a suitable molecular target to use in developing tumor imaging methods. Our earlier study using xenograft model with KB (FRα +ve) and A549 (FRα -ve) cells implanted subcutaneously on the flank region of female athymic nude mice demonstrated higher level tumor accumulation of folate-NPs in KB tumor compared to A549 tumor, detectable by SPMR and MRI. To translate such results into a potential clinical application, we recently generated two orthotopic mice ovarian cancer models by implanting KB cells surgically into ovary as well intraperitoneally (IP) into mice abdominal cavity (metastasis model). Implanted tumor cells were allowed to grow for about 2 weeks. Folate-NPs (20mg Fe/kg) were delivered via tail vein or IP injections. PEG-NPs were also delivered as controls. Mice were euthanized 24-hour post-dosing. Mesenteric tumor tissue and reproductive organs with tumors were resected and measured on SPMR. Same tissues from mice without NP injection or with PEG-NP injection were also measured. Our results demonstrated that Folate-NPs reached the tumor sites in both orthotopic models and accumulated specifically at high level detectable by SPMR ex vivo. The amount of NP accumulation in mice with orthotopically implanted tumor was 3x-10x more than those of the xenograft subcutaneous flank implanted tumor model, indicating efficient NP delivery and binding of NP with tumor cells in its natural tissues/organs. The repeat studies of these orthotopic mice models used in the SPMR experiment are currently being conducted using MRI as an alternative in vivo detection method with images taken pre- and post- dosing of the NPs. We anticipate that folate-NPs presence in the tumors will be easily observable on MRI images as it produces T2 contrast along with additional anatomical information. Favorable orthotopic mice model results presented here will lay the groundwork for IND-enabling development of these targeted NP as T2 contrast agent for early ovarian cancer detection using MRI. This type of targeted imaging technology will improve the accuracy of cancer detection in vivo without the use of radioisotopes or radiation, therefore, minimize the needs of invasive biopsies/surgery, with further potential of monitoring therapy response or recurrence. Citation Format: Marie Zhang, Yamitha Perera, Kathirvel Kandasamy, Dan Inglese. In vivo ovarian cancer detection using folate receptor-α targeted iron oxide nanoparticles [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B045.

Synergetic Effect of β-Cyclodextrin and CuO Nanocomposite for Ultrasensitive Determination of Chloramphenicol in Food

Chloramphenicol (CAP), a broad-spectrum antibiotic, has severely impacted human health and the ecological environment, which brings an increasing demand for an efficient monitoring technology for rapid and sensitive antibiotic residue detection. Herein, a highly sensitive and selective electrochemical sensor was developed for detecting CAP, based on the synergistic effect of β-cyclodextrin (β-CD) and CuO-nanomaterials modifying glassy carbon electrode (GCE). Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) spectrometry were used for morphological characterization. β-CD/CuO/GCE sensor with high-specific surface area and cavity structure was prepared by modifying GCE for further electrochemical testing. Experimental parameters were optimized using square wave stripping voltammetry. The developed sensor obtains an ultra-wide linear range from 1.0 × 10−7 mol l−1 to 5.0 × 10−4 mol l−1and the limit of detection is 0.5 × 10−7 mol l−1. The sensor displays high sensitivity, remarkable stability, and reproducibility; particularly more convenient than the Liquid chromatography-mass spectrometry (LC-MS) verification method. Furthermore, the applicability of the developed β-CD/CuO/GCE sensor was demonstrated by detecting CAP in food samples.