Fluorescent Nanoparticles Research Articles

MUC1 and glycan probing of CA19-9 captured biomarkers from cyst fluids and serum provides enhanced recognition of ovarian cancer

Glycosylation changes of circulating proteins carrying the CA19-9 antigen may offer new targets for detection methods to be explored for the diagnosis of epithelial ovarian cancer (EOC). Search for assay designs for targets initially captured by a CA19-9 antigen reactive antibody from human body fluids by probing with fluorescent nanoparticles coated with lectins or antibodies to known EOC associated proteins. CA19-9 antigens were immobilized from ascites fluids, ovarian cyst fluids or serum samples using monoclonal antibody C192 followed by probing of carrier proteins using anti-MUC16, anti-MUC1 and, anti STn antibodies and seven lectins, all separately coated on nanoparticles. Compared to reference CA19-9 and CA125 immunoassays, nanoparticle aided detection using MUC16, Ma695 and STn antibodies and lectin WGA provided, both separately and combined, improved discrimination of EOC and borderline cancers from benign samples when applied to 60 cyst fluid specimens. When applied to a panel of 44 serum samples (EOC N = 24, healthy and benign samples N = 20) two assays, CA19-9Ma695 and CA19-9MUC1, stood out with equally superior separations (p-values < 10–8) of the two groups compared to conventional CA19-9 immunoassay (p-value 0.03).Eu+3 -NP based CA19-9MUC16, CA19-9Ma695, CA19-9STn and CA19-9WGA show promise for improved EOC detection when applied to ascites & cyst fluids. When applied to circulation-derived samples, the two MUC1 based assays, CA19-9Ma695 and CA19-9Ma552 outperformed other assay constructs. Our results call for further validation in larger EOC cohorts preferentially with early stage ovarian cancers and all major histotypes against commonly occurring benign conditions.

Fluorescent Heterocyclic Compound-Loaded Bi2Se3-Polysorbate Nanoparticles for Targeted Therapy in Non-Small Cell Lung Cancer.

This study introduces a novel approach for non-small cell lung cancer (NSCLC) treatment by developing Bi2Se3-Polysorbate nanoparticles as a multifunctional platform for photothermal therapy and targeted drug delivery. The Bi2Se3-Polysorbates nanoparticles are engineered as innovative photosensitive drug carriers, enhancing biocompatibility through the combination of Bi2Se3 and Polysorbates. Characterization techniques such as Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ultraviolet-visible (UV-Vis) spectroscopy confirm the successful synthesis of the nanoparticles. In a breakthrough step, these nanoparticles are combined with a novel heterocyclic drug (drug-1), verified by single-crystal analysis, to create the Bi2Se3-Polysorbates@drug-1 composite. Biological evaluations show that the system significantly inhibits cell proliferation in NSCLC cells, and molecular docking studies reveal that drug-1 interacts with the target protein through hydrogen bonds, halogen bonds, and hydrophobic interactions, suggesting promising anti-cancer activity. This research presents a novel multifunctional nanoplatform for effective drug delivery and offers a new strategy for the treatment of NSCLC, demonstrating significant advancements in cancer therapy.

Integrating Particle Motion Tracking into Thermal Gel Electrophoresis for Label-Free Sugar Sensing.

Bioanalytical sensors are adept at quantifying target analytes from complex sample matrices with high sensitivity, but their multiplexing capacity is limited. Conversely, analytical separations afford great multiplexing capacity but typically require analyte labeling to increase sensitivity. Here, we report the development of a separation-based sensor to sensitively quantify unlabeled polysaccharides using particle motion tracking within a microfluidic electrophoresis platform. Carboxymethyl dextran (20 kDa) was spiked into Pluronic thermal gel along with fluorescent nanoparticles (200 nm diameter) and loaded into single-channel microfluidic devices. Upon voltage application, the soluble sugar enriched into a concentrated band that induced motion of the insoluble particles as it passed. Bead displacement was tracked over time to produce electropherograms where peak areas were proportional to analyte concentrations. Key studies herein established the range of acceptable operating conditions (e.g., gel concentration, temperature) to characterize how the temperature-dependent rigidity of thermal gel influenced the analysis. Data processing strategies were then evaluated to identify conditions (e.g., exposure intervals, particle averaging, motion directionality) to maximize sensitivity. The quantitative response of the method was evaluated over a broad concentration range (0.5-5000 nM) where detection limits were found to be 520 pM for the 20 kDa sugar, providing a 106-fold superior mass LOD than a gold standard UV-vis absorbance method. Studies into the detection mechanism found that sensitivity was dependent on the molecular weight of the sugar as larger sugars produced greater responses. Collectively, these studies established best practices for integrating particle sensing into thermal gel separations for label-free polysaccharide quantitation.

Fluorescence nanosensor based on modified sustainable silica for highly sensitive detection of SARS-CoV-2 IgG antibody

This study presents an innovative fluorescence nanosensor utilizing modified sustainable silica for the ultra-sensitive detection of SARS-CoV-2 IgG antibodies. The sensor employs fluorescent dye-doped silica nanoparticles (FSNP) synthesized via the...

Building Up Functional Coiled-Coil-Based Supramolecular Assemblies for Biomedical and Biotechnological Applications.

The self-assembling nature of coiled-coils has brought this common structural motif into the spotlight of protein design since it offers a customizable framework for engineering innovative protein nanoparticles with tailored functionalities. We recently harnessed the self-assembling capabilities of ZapB, a bacterial coiled-coil protein, to build up fluorescent protein nanoparticles possessing remarkable affinity for antibodies. Here, we describe a complete workflow detailing the design, production, and characterization of such coiled-coil-based protein nanostructures. Additionally, we detail their functionalization with specific antibodies and illustrate their utility in stimulating the activation and proliferation of human T cells, underscoring the potential of these protein-only nanoparticles in immunotherapeutic interventions.

Dye‐Based Fluorescent Organic Nanoparticles, New Promising Tools for Optogenetics (Adv. Healthcare Mater. 2/2025)

Dye‐Based Fluorescent Organic Nanoparticles, New Promising Tools for Optogenetics (Adv. Healthcare Mater. 2/2025)

Dynamics of nanoparticle tracers in supercooled nanoparticle matrices.

We investigate the dynamics of tracer nanoparticles in bulk supercooled nanoparticle matrices using confocal microscopy. We mix fluorescent (tracer) and undyed (matrix) charged-stabilized polystyrene nanoparticles with tracer-to-matrix particle size ratios δ = 0.34, 0.36, 0.45, 0.71 at various matrix volume fractions ϕ. Single-particle and collective dynamics were obtained from particle-tracking algorithms and differential dynamic microscopy (DDM), respectively. The long-time behavior of the tracer mean-square displacement (MSD) and the shape of the distributions of particle displacements depend on δ and ϕ. At sufficiently large ϕ, small tracers (δ ≤ 0.36) remain mobile and subdiffusive but large tracers (δ ≥ 0.45) are dynamically arrested. The relaxation times determined from the intermediate scattering function (ISF) increase with δ and ϕ. Anomalous logarithmic decays in the ISF are observed for tracers of size δ ≤ 0.36 over a length scale of four to ten matrix particle diameters. These results provide insight into how penetrant size affects the transport of nanoparticles in porous media with soft interparticle interactions.

3D real-time single particle tracking using two-photon fluorescence from bright dye-based organic nanoparticles.

This paper addresses the use of ultrabright dye-based fluorescent organic nanoparticles in a 3D single-particle tracking two-photon microscopy setup. The nanoparticles consist of an assembly of quadrupolar dyes, presenting a large two-photon absorption cross-section. They exhibit low photobleaching, crucial for long-term tracking, and their high brightness allows nanometer localization precision. Their small size compared to previously used nonlinear inorganic nanocrystals, stable structure at physiological temperature, and adjustable optical properties make them promising tools for further biological research. This study highlights their potential to track dynamic processes with precision and stability, paving the way for exploring cellular processes at the nanoscale.

Quantitative fluorescent nanoparticle tracking analysis and nano-flow cytometry enable advanced characterization of single extracellular vesicles.

Current state-of-the-art tools for analysing extracellular vesicles (EVs) offer either highly sensitive but unidimensional bulk measurements of EV components, or high-resolution multiparametric single-particle analyses which lack standardization and appropriate reference materials. This limits the accuracy of the assessment of marker abundance and overall marker distribution amongst individual EVs, and finally, the understanding of true EV heterogeneity. In this study, we aimed to define the standardized operating procedures and reference material for fluorescent characterization of EVs with two commonly used EV analytical platforms-nanoparticle tracking analysis (NTA) and nano-flow cytometry (nFCM). We achieved quantitative fluorescence analyses on ZetaView NTA and NanoAnalyzer nFCM instruments, by utilizing yellow-green FluoSpheres (FS) with assigned ERF (equivalent reference fluorophore) values. This standardization technique allowed for fluorescent EV signal to be expressed in ERF units (indicative of bound fluorescent antibodies per EV), thus enabling measurement of target protein marker abundance on individual EVs, and in the whole EV population. The NTA's and nFCM's limits of detection (LoD) were evaluated at 21 and 9 Alexa Fluor 488 (AF488) molecules, respectively. To complement the limited quantification of markers expressed in a few copies per single EV, in-line bulk fluorescence measurements with a plate reader were performed. This provided absolute marker quantification and more insightful analyses of EV heterogeneity and marker stoichiometry. The standardization method outlined in this work unlocks the full analytical potential of NTA and nFCM, enabling cross-platform data comparison. At the same time, it highlights some of the technical challenges and considerations and thus contributes to the ongoing efforts towards the development of EV analytical tools.

ICT-based fluorescent nanoparticles for selective cyanide ion detection and quantification in apple seeds.

In this report, we successfully engineered a novel probe based on an acceptor-donor-acceptor (A-D-A) architecture featuring dicyanovinyl-substituted thieno[3,2-b]thiophene, termed DCVTT. The designed probe self-assembles into luminous nanoparticles (DCVTT NPs) upon introducing mixed aqueous solutions. These fluorescent nanostructures served as a ratiometric probe for detecting cyanide (CN-) ions in aqueous-based environments, owing to the robust Intramolecular Charge Transfer (ICT) characteristics of DCVTT. The A-D-A substituents in DCVTT significantly enhanced ICT behavior by promoting more efficient electron transfer between the donor and acceptor groups. This improved electron transfer process leads to heightened sensitivity in detection applications. In the case of cyanide (CN) sensing, this enhanced ICT behavior manifests as a strong colorimetric response, allowing for a visible color change before and after interaction with cyanide. Speculation regarding the interaction mechanism between DCVTT and CN- is proposed based on the findings of various experimental analyses. The detection limit (LOD) for DCVTT in identifying CN- is 0.83 nM, significantly lower than the CN- concentration thresholds deemed safe by the World Health Organization (WHO) and the United States Environmental Protection Agency (EPA). Time-Dependent Density Functional Theory (TD-DFT) has been utilized to theoretically analyze the optical properties of DCVTT both before and after the introduction of the CN- ions. A paper-based test strip was developed to demonstrate its practical application to enable efficient qualitative CN- detection by visual inspection. Furthermore, this sensing platform demonstrates highly accurate quantitative detection of CN- in apple seeds. No prior reports have utilized fluorescence techniques to estimate apple seeds' CN levels.

Ultrasensitive turn-off fluorescent sensor for estimation of the new influenza antiviral prodrug baloxavir marboxil in its pharmaceutical formulation.

Carbon quantum dots (CQDs) are a recently developed class of fluorescent nanoparticles made from carbon. Co-doping with heteroatoms such as nitrogen and sulfur improved the properties and generated a high quantum yield. In the proposed study, we utilized a simple, cost-effective, single-stage hydrothermal approach to produce extreme photoluminescence co-doped, nitrogen and sulfur, CQDs (N,S-CODs). Thiosemicarbazide was used as a nitrogen and sulfur source, while citric acid was used as a carbon source to produce fluorescent probes. The prepared N,S-CQDs were subjected to extensive characterization. The generated N,S-CQDs yielded strong fluorescence emission at λ em 430.0 nm after excitation at λ ex 360.0 nm, with a relatively high quantum yield of 41.3% utilizing quinine sulfate as a reference fluorescent compound. These N,S-CQDs were applied as fluorescent nanosensors for the ultrasensitive spectrofluorimetric determination of baloxavir marboxil (BXM) directly without pre-derivatization for the first time. BXM effectively quenches the native fluorescence of N,S-CQDs. Considering the optimal conditions, the fluorescence intensity reduction of N,S-CQDs exhibited a 'turn-off' response to BXM at concentrations of 10.0-100.0 ng ml-1, with detection limits of 1.88 ng ml-1 and quantitation limits of 5.69 ng ml-1, respectively. The proposed method determined BXM successfully in its tablet dosage form and further expanded to confirm the content uniformity of the tablet units in agreement with USP guidelines.

Liquid-nano-liquid interface–oriented anisotropic encapsulation

Emulsion interface engineering has been widely employed for the synthesis of nanomaterials with various morphologies. However, the instability of the liquid-liquid interface and uncertain interfacial interactions impose significant limitations on controllable fabrications. Here, we developed a liquid-nano-liquid interface-oriented anisotropic encapsulation strategy for fabricating asymmetric nanohybrids. Specifically, functional nanoparticles such as magnetic nanoparticles, lanthanide fluorescent nanoparticles, and Au nanorods were anisotropically encapsulated by mesoporous polydopamine (mPDA). In this emulsion system, the wetting behavior of functional nanoparticles at the water/oil interface could be manipulated by the stabilizer of the emulsion (surfactant), leading to the anisotropic assembly of mPDA shell and resulting in various nanostructures, including core-shell, yolk-shell with small opening, ball-in-bowl, and multipetal structures. Due to their structural asymmetry, inherent magnetic properties, and photothermal properties, the ball-in-bowl structured Fe3O4@SiO2&mPDA nanohybrids, serving as proof of concept for nanomotors, demonstrated effective penetration of bacterial biofilm and promotion of infected wound healing. Overall, our approach offers a different perspective for designing morphologically controllable asymmetric structures based on liquid-nano-liquid interface in microemulsion systems that hold great potential for establishing innovative functional nanomaterials.

Engineering an Ionic Aggregation-Induced Luminescence-Labeled Fluorescence Lateral Flow Immunoassay for C-Reactive Protein in Human Plasma.

The surge of lateral flow immunoassays (LFAs) stimulates researchers to explore the novel vibrant aggregation-induced emission luminogen (AIEgen)-doped nanoparticles to improve the accuracy and reliability of LFAs. However, the loading amount of AIEgens currently used for the LFA in microspheres is limited due to their symmetrical large conjugated skeleton structure, which significantly reduces the fluorescence brightness of the signal reporter in the LFA. Herein, an ionic AIEgens with a donor-acceptor type was developed as the signal reporter of the LFA for C-reactive protein (CRP). Ionic AIEgens are unable to enter the hydrophobic cavity of polystyrene nanoparticles (PS) because of their low hydrophobic nature. By altering ionic AIEgens with extended alkyl chains, it is possible to increase their hydrophobicity, thereby potentially increasing the loading capacity within PS. Notably, the fluorescent nanoparticles (denoted as AIETPANPs) formed by embedding (E)-4-(4-(diphenylamino)styryl)-1-octadecylpyridin-1-ium iodide (TPA) in PS showed orange-red fluorescence emission and have high fluorescence quantum yield. Anti-CRP antibody (mAb1) could be effectively conjugated to the surface of AIETPANPs by an amino-carboxyl reaction, resulting in AIETPANPs-mAb1. The AIETPANPs-mAb1 exhibited a fluorescence emission at 613 nm, a point detectable by the naked eye with minimal background interference. The entire analysis was accomplished in just 10 min, achieving a limit of detection of 4.06 ng/mL for CRP. The AIETPANPs-mAb1-based LFA demonstrates excellent stability and specificity and fully meets the requirements for clinical diagnosis.

PDDA-Assisted Synthesis of Magnetic Fluorescent Fe3O4@SiO2-CQD Composites.

Magnetic fluorescent nanomaterials have broad application prospects as taggants in fields such as anticounterfeiting identification, suspicious object tracking, and potential fingerprint recognition in forensic medicine. It is a common method to synthesize magnetic fluorescent composite nanoparticles by preparing a shell on the surface of magnetic particles to load fluorescent materials. In this work, a magnetic fluorescence nanohybrid was synthesized by in situ encapsulation of carbon quantum dots (CQDs) during the preparation of a SiO2 shell on the surface of Fe3O4 nanoparticles. The traditional Stöber method was employed to synthesize the SiO2 shell. Meanwhile, CQDs were introduced into the hydrolysis process of tetraethyl orthosilicate. To address the issue of charge repulsion between the negatively charged hydrolysis intermediate of tetraethyl orthosilicate and the negatively charged CQDs, poly(diallyldimethylammonium chloride) with positive charge was introduced in the synthesis process. The repulsive charges in the reaction system were balanced by poly(diallyldimethylammonium chloride), allowing for the successful encapsulation of CQDs in the SiO2 shell. The structure, morphology, and magnetic and fluorescence properties of the prepared Fe3O4@SiO2-CQDs were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, a vibrating sample magnetometer, and a fluorescence spectrophotometer. The Fe3O4@SiO2-CQDs exhibited excellent magnetic and fluorescence properties, making them suitable for fluorescence labeling on various substrates and showing great potential in labeling, tracing, and fluorescence sensors.

An Augmented Reality Visor for Intraoperative Visualization, Guidance, and Temperature Monitoring Using Fluorescence

ABSTRACTFluorescence‐guided surgeries, including tumor resection and tissue soldering, are advancing the frontiers of surgical precision by offering enhanced control that minimizes tissue damage, improving recovery and outcomes. However, integrating fluorescence visualization with real‐time temperature monitoring remains a challenge, limiting broader clinical use. We address this issue with an augmented reality (AR) visor that combines nanomaterial excitation, fluorescence detection, and temperature monitoring. Using advanced fluorescent nanoparticles like indocyanine green‐doped particles and carbon nanotubes, the visor provides a comprehensive view of both the surgical field and sub‐surface conditions invisible to the naked eye. This integration improves the safety and efficacy of fluorescence‐guided surgeries, including laser tissue soldering, by ensuring optimal temperatures and laser guidance in real time. The presented technology enhances existing surgical techniques and supports the development of new strategies and sensing technologies in areas where traditional methods fall short, marking significant progress in precision surgery and potentially improving patient care.

Role of Oxygen Defects in Eliciting a Divergent Fluorescence Response of Single-Walled Carbon Nanotubes to Dopamine and Serotonin.

Modulating the optical response of fluorescent nanoparticles through rational modification of their surface chemistry can yield distinct optical signatures upon the interaction with structurally related molecules. Herein, we present a method for tuning the fluorescence response of single-walled carbon nanotubes (SWCNTs) toward dopamine (DA) and serotonin, two structurally related monoamine-hydroxylated aromatic neurotransmitters, by introducing oxygen defects into (6,5) chirality-enriched SWCNTs suspended by sodium cholate (SC). This modification facilitated opposite optical responses toward these neurotransmitters, where DA distinctly increased the fluorescence of the defect-induced emission of SWCNTs (D-SWCNTs) 6-fold, while serotonin notably decreased it. In contrast, pristine, defect-free SWCNTs exhibited similar optical responses to both neurotransmitters. The underlying mechanisms for the divergent fluorescence response were found to be polydopamine (PDA) surface adsorption in the case of the fluorescence enhancement in response to DA, while the fluorescence decrease in response to serotonin was attributed to enhanced solvent relaxation effects in the presence of defects. Importantly, the divergent optical response of D-SWCNTs to DA and serotonin, via the introduction of defects, was validated in complex biological environments such as serum. Further, the generality of our approach was confirmed by the demonstrations of a divergent fluorescence response of D-SWCNTs suspended by an additional dispersant, namely lipid-polyethylene glycol (PEG). This study offers promising avenues for the broad applicability of surface functionalization of SWCNTs to achieve divergent responses toward structurally related molecules and advance applications in sensing, imaging, and diagnostic technologies.

Preparation of β-Myrcene-Chitosan Nanoparticles and Their Uptake and Toxicity in Aedes aegypti Larvae.

Mosquito control still relies heavily on synthetic molecules, which can lead to the selection of resistant populations and undesirable environmental problems. This study described the preparation of a nanoparticle of the plant-derived molecule, β-myrcene, with chitosan, and the assessment of its toxicity against larvae of the yellow fever mosquito, Aedes aegypti. By producing fluorescent chitosan nanoparticles, we were able to observe their distribution in the digestive tract of larvae of Ae. aegypti. Chitosan-based nanoparticles containing β-myrcene (238 mg/L) could kill 100% of the larvae tested, whereas the blank control (i.e., the nanoparticle without β-myrcene) showed no larvicidal activity. The chitosan nanoparticles with β-myrcene had a zeta potential of +15 mV and a hydrodynamic diameter ranging from 30 to 2800 nm. The blank control, without β-myrcene, had a zeta potential of +26 mV and a diameter of 30 to 830 nm. Fluorescence analysis showed that the nanoparticles were efficiently absorbed and distributed in the digestive tract organs of the Ae. aegypti larvae. In short, our results reinforce the benefits of using chitosan to carry molecules of plant-derived-molecules, such as β-myrcene, in mosquito control, suggesting a broad internal distribution that contributes to their toxicity.

NIR-II Ratiometric Optical Theranostic Capsule for In Situ Diagnosis and Precise Therapy of Intestinal Inflammation.

Capsules were widely used in clinical settings for the oral delivery of various drugs, although it remains challenging to trace real-time drug release behavior and adjust dosages based on the therapeutic effect. To address these issues, we developed theranostic capsules that loaded two kinds of fluorescence nanoparticles, H2O2-responsive Janus Ag/Ag2S nanoparticles (Ag/Ag2S JNPs) and the downconversion nanoparticles (DCNPs), and the dexamethasone (Dex) drug. The Ag/Ag2S JNPs exhibit a highly sensitive fluorescence (FL) signal at 1250 nm in response to H2O2, while the FL signal from the DCNPs at 1550 nm remains stable under physiological conditions. The ratio of these two FL signals formed the ratiometric FL signal, which shows correlation with the H2O2 concentration with a detection limit of 1.7 μM. Moreover, the capsules can be precisely delivered into the intestine, where they release the JNPs and DCNPs simultaneously. The H2O2-triggered ratiometric FL signals and images can diagnose inflammation and indicate its location. Meanwhile, the encapsulated Dex is released in the disease region, with ratiometric imaging allowing for real-time tracking of therapeutic efficacy and providing guidance for ongoing treatment. The theranostic capsule system provides an approach for quantitative detection of disease biomarkers and further localized release of therapeutics, thereby avoiding overdose and reducing side effects.

Facile synthesis of stable and fluorescent carbon nanoparticles from brewery bagasse for value-added applications

Facile synthesis of stable and fluorescent carbon nanoparticles from brewery bagasse for value-added applications

Dissolving microneedle array patches containing mesoporous silica nanoparticles of different pore sizes as a tunable sustained release platform.

Dissolving microneedle array patches (DMAP) enable efficient and painless delivery of therapeutic molecules across the stratum corneum and into the upper layers of the skin. Furthermore, this delivery strategy can be combined with the sustained release of nanoparticles to enhance the therapeutic potential in a wide variety of pathological scenarios. Among the different types of nanoparticles that can be included in microneedle formulations, mesoporous silica nanoparticles (MSN) of tunable pore sizes constitute a promising tool as drug delivery systems for cargos of a wide range of molecular weights. In this work, a new preparation method was developed to produce DMAP containing ca. 2.3mg of MSN of different pore sizes located mainly in the microneedle tips. The successful insertion of these DMAPs was confirmed in vitro (using Parafilm), ex vivo (using excised neonatal porcine skin) and in vivo (in the back of mice). The dissolution of the microneedles and deposition of the nanoparticles inside the skin were also confirmed both ex vivo and in vivo using fluorescent nanoparticles (with an intradermal deposition of 20.9±7.26% of the MSN in each DMAP in neonatal porcine skin). Finally, the in vivo release of the cargo from nanoparticles deposited inside mouse skin after microneedle insertion was confirmed through in vivo fluorescence measurements.