Research Interests

Cationic Carbon Dots in DNA Binding and Tumor Inhibition

Metformin Carbon dots in Pancreatic Cancer Treatment

Pancreatic Ductal Adenocarcinoma (PDAC) is a highly aggressive cancer with a poor prognosis due to its dense stromal microenvironment, tumor heterogeneity, and rapid development of drug resistance. Gemcitabine (GEM), a first-line FDA-approved chemotherapy for PDAC, remains ineffective at standard doses, often requiring high concentrations that results in severe side effects. Metformin (MET), a widely used antidiabetic agent, has emerged as a potential stromal modulator that can reshape the PDAC tumor microenvironment.

We propose utilizing non-toxic, fluorescent carbon dots derived from MET (MetCDs) as an efficient nanocarrier for GEM in PDAC therapy, leveraging their positive surface potential and structural resemblance to glutamine, a crucial amino acid for cancer cell proliferation, to enhance tumor targeting and drug delivery. To enable comparative analysis, studies were parallelly conducted on CND-GEM conjugate, synthesized from Carbon Nitride Dots (CNDs)—a similar nanomaterial with negative surface potential, proven to have selective cancer cell uptake.

Additionally, we aim to investigate the potential of combining nanotechnology and combination chemotherapy to effectively address the heterogenous nature and drug resistance in PDAC tumors. Specifically, we conjugated Idarubicin (IDR), an anthracycline drug commonly used in combination regimens, on carbon dots alongside GEM, to compare the efficacy to their mono-conjugate counterparts.

Pediatric Brain Tumor and Lymphoma

Our group also focuses on treating pediatric brain tumors, the leading cause of cancer-related deaths in children. Current treatments have severe side effects, prompting the development of carbon dots (CDs) for targeted drug delivery and fluorescence-guided surgery. We created a triple-conjugated CD system with transferrin, epirubicin, and temozolomide, which showed strong cytotoxicity and synergistic effects in brain tumor cells. Additionally, carbon nitride dots selectively entered SJGBM2 cells and emitted red photoluminescence, highlighting their potential for tumor imaging and surgical guidance.                             

Figure 4: Schematic illustration of a triple conjugated system composed of transferrin, epirubicin and temozolomide on the carboxylic acid functionalized C-dots (CDs). 

A novel approach to treat diffuse large B-cell lymphoma (DLBCL) was presented by our group in collaboration with Johnathan Schatz’ Lab (University of Miami). It consists of direct delivery of doxorubicin (Dox) to the tumor through the use of a chemotherapeutic-nanocarrier system, composed of carbon nitride dots (CND), Dox and transferrin (TF). According to the gain and loss of function studies, the TF is the key of tumor targeting. This system has shown 10-100 times more effectiveness against DLBCL cell lines than Dox alone. In vivo studies also presented significant results in mice survivability due to the reduced toxicity and tumor reduction caused by the direct delivery of drug. In order to improve the novel drug delivery system, studies are redirected to the increase of drug loading of Dox on CND and analyses of biomechanisms of drug release inside the cell.

Synthesis of Novel Chalcone Derivatives for Cancer Therapy

Chalcones as weandhetic analogues have attracted much interest due to their broad biological activities with clinical potentials against various diseases, particularly for antitumor activity. Design and development of new chalcone derivatives may improve the anticancer efficiency. In this project, many chalcone derivatives have been prepared and investigated in anti-glioblastoma cells. Meanwhile, conjugation of these derivatives with transferrin-CDs were performed. It was found that the conjugates were significantly more cytotoxic than the free chalcones.

Photodynamic Therapy

The lowest excited state of oxygen, singlet oxygen, has been shown to have promising results in medicinal purposes for many years. Typically, singlet oxygen is produced through irradiation of a photosensitizer, which are generally porphyrins, chlorophylls or dyes. Singlet oxygen possesses high reactivity towards a wide range of molecules, due to its strong oxidizing nature. This has led many to use it as a source of cancer treatment through selectively irradiating a tumorous area in the presence of a specific photosensitizer. Our goal is to use this approach externally, for treatments of Methicillin-resistant Staphylococcus aureus (MRSA) and fungal infections found on the eye. Treatment outside the body allows for a wider range of possible photosensitizers to be used, as the irradiation source does not need to penetrate many layers of skin or flesh to reach the infected area.

Organic Fluorophore-based Red Emissive Carbon Dots in Glioblastoma Imaging

In this study, we utilized indocyanine green (ICG), an FDA-approved NIR fluorophore as a precursor to synthesize water-soluble, red-emissive CDs with a peak emission at 697 nm. ICG was chosen for its clinical advantages, including low toxicity, NIR-region usability, and strong affinity for blood lipoproteins. Compared to free ICG, the resulting R-CDs exhibited enhanced thermal stability, photobleaching resistance, and a 50% increase in photothermal conversion efficiency, along with excellent photothermal cyclability across a broad pH range. These R-CDs also demonstrated tunable blood–brain barrier (BBB) penetration and tumor-targeting capabilities through peptide surface functionalization. Their stable red emission and improved photothermal properties position them as promising agents for bioimaging and targeted phototherapy.         

Figure 5a: Graphic visualization of the transit of R-CD-Tf via the BBB into the CNS as compared to R-CD in zebrafish

These ICG-derived CDs demonstrated strong red fluorescence for imaging glioblastoma stem-like cells (GSCs), along with low toxicity. Post-synthetic modifications further enhanced their tumor selectivity and enabled successful blood–brain barrier (BBB) penetration in zebrafish models. These findings highlight the potential of ICG-based CDs as multifunctional agents for targeted imaging and phototherapy in brain cancer.     

Figure 5b: GSCs were exposed to 500 μg/mL for 1 h and the fluorescent intensity observed.

Red Emissive Chlorophyllin Carbon Dots Harnessing Fenton-Fueled Ferroptosis

In this study, copper chlorophyllin-based CDs (Chl-D CDs) were synthesized, exhibiting strong red emission at 654 nm with a high quantum yield of 20–25%. This exceptional optical performance positions Chl-D CDs as dual-function agents-serving both as effective imaging probes and therapeutic tools. 

Chl-D CDs demonstrated the ability to induce a Fenton-like reaction, enhancing photodynamic therapy (PDT) through ferroptotic and apoptotic pathways. To further boost therapeutic efficacy, the anticancer drug temozolomide was conjugated to their surface, resulting in a synergistic effect between PDT and chemotherapy. The CDs showed excellent biocompatibility in immune cells and in vivo models, reinforcing their clinical promise.         

Figure 6b: The addition of Chl-D CDs and H2O2 in a combination that was subjected to 520 nm light radiation for 1 h lowered the PL emission maximum band of Evans blue substantially.

Water-Soluble Porphyrin-Like Self-Assembling Carbon Dots

o-Phenylenediamine-based Red-Emissive Carbon Dots for Bioimaging

o-Phenylenediamine (o-PDA) was combined with various precursors in solvents of differing acidity and oxidative strength to investigate the formation of red-emissive carbon dots (CDs) sensitive to water. The results revealed that both acid catalysis and oxidation are critical, promoting o-PDA oligomerization and crosslinking into aromatic structures responsible for red emission.

These CDs demonstrated high sensitivity for quantitative water detection in organic solvents. Conjugation with transferrin significantly improved their biocompatibility, enabling successful bioimaging of neuroblastoma cell lines with and without N-myc amplification. This study not only advances understanding of red-CD formation but also highlights their potential in tumor-specific imaging applications.

Figure 8b: Graphical illustration of CD preparation and application and 

Synthesis of Novel Red-Emissive Fluorophores and Carbon Dots

The synthesis of novel red-emissive fluorophores for carbon dot (CD) fabrication holds significant promise for advancing biosensing and bioimaging technologies. Red-emitting CDs offer deeper tissue penetration and reduced background interference due to minimal autofluorescence in biological systems. These fluorophores enable the development of CDs with high quantum yields and stable photoluminescence in the red to near-infrared region. Such properties are crucial for real-time, non-invasive imaging and highly sensitive detection of biomolecules. This approach paves the way for next-generation diagnostic tools with enhanced precision and biocompatibility.

A Combination Nanoplatform

Exosomes, once dismissed as cellular waste, are now emerging as powerful nanocarriers for drug delivery due to their biocompatibility and immune-evasive properties. However, their limited tracking and loading capabilities hinder broader application. Integrating carbon dots (CDs) renowned for their photoluminescence, water solubility, and safety addresses these limitations. This dual-platform system enables real-time tracking and efficient therapeutic delivery across biological barriers. The synergy between exosomes and CDs holds transformative potential for targeted treatment and early diagnosis of diseases like cancer and Alzheimer’s.

Thiolated Carbon Dots as Potential Anti-viral Agents

Although the World Health Organization has declared the end of the SARS-CoV-2 public health emergency, coronavirus-related research remains critical. As of 2024, COVID-19 severity has declined due to vaccines and treatments, yet severe complications still occur, underscoring the need for innovative therapeutic strategies.This study explores viral entry mechanisms and the therapeutic potential of sulfhydryl (thiol) groups in COVID-19 treatment. We developed biocompatible thiol-functionalized carbon dots (CDs) and examined how thiol content influences pseudo-SARS-CoV-2 inhibition, reactive oxygen species (ROS) scavenging, and anti-inflammatory activity.

Figure 9a: Circular dichroism spectra of bare spike protein RBD and after incubation with 5 mM DTT and 0.4 mg/mL CystaD 1−1 and CystaD 2−1.

To investigate the effect of thiols, two different molar ratios of precursors citric acid and cyteamine were utilized to obtain CystaD 1-1 and CystaD 2-1. Thiolated CDs demonstrated strong free radical scavenging, effective ROS regulation, and high cell viability. Notably, they achieved up to 60.4% viral inhibition and promoted anti-inflammatory responses under inflammatory conditions, as shown by flow cytometry. A clear correlation was observed between thiol density and therapeutic efficacy, positioning thiolated CDs as promising candidates for preventing and treating COVID-19 and related viral infections.

Figure 9b: Viral infection levels calculated for viral inhibition of both CDs. 

Drug Delivery Across the Blood-Brain Barrier

One of the major challenges in treating brain tumors or neurodegerative disorders are the inability of many therapeutic agents to cross the blood–brain barrier (BBB), a selective physiological barrier that protects the central nervous system (CNS) from harmful substances. While essential for neuroprotection, the BBB significantly limits drug delivery, allowing only molecules with specific physicochemical properties to pass through. Traditional methods to bypass the BBB, such as ultrasound, heat, osmotic pressure, or microbubbles pose high risks due to their disruptive nature. As a safer alternative, recent research has focused on nanoparticle-based delivery systems capable of crossing the BBB without compromising its integrity.

Figure 10(a): Graphical illustration of carbon dots crossing the blood-brain barrier

Glucose-derived carbon dots (GluCDs) were designed to mimic glucose and exploit GLUT1 transporters for blood–brain barrier (BBB) crossing. We hypothesized that GluCDs possess glucose-like surface groups, enabling transporter-mediated uptake and CNS delivery. Fluorescein-labeled GluCDs (GluCD-F) were synthesized and tested in yeast, zebrafish, and rat models. Results confirmed GLUT1-dependent uptake and successful BBB penetration, highlighting GluCDs as promising nanocarriers for CNS-targeted drug delivery.

Figure 10(b): Confocal image of transgenic zebrafish.

Among these, transferrin (Tf)-mediated delivery has gained attention. Tf, an 80 kDa iron-transport protein, utilizes receptor-mediated endocytosis to cross the BBB, exploiting the abundance of Tf receptors on brain endothelial cells and many cancer cells. This dual targeting potential makes Tf an attractive ligand for tumor-specific drug delivery. For instance, Tf-conjugated polymeric nanoparticles have been shown to effectively deliver doxorubicin to resistant breast cancer cells with reduced toxicity to healthy tissues, as validated in zebrafish models. These findings underscore the promise of Tf-functionalized nanocarriers in overcoming BBB-related therapeutic barriers in CNS diseases.

Alzheimer’s disease (AD) is the most common cause of dementia in the elderly, affecting an estimated 30 million people globally and ranking as the sixth leading cause of death in the U.S. While several FDA-approved drugs exist, only recently approved anti-amyloid antibodies such as Lecanemab and Donanemab have shown meaningful potential to slow disease progression. Despite its prevalence, no disease-modifying treatments currently exist, but only medications that ease symptoms. Our research focuses on developing carbon dots (CDs) and CD conjugates as potential therapeutics and drug carriers for AD. Several CD-based systems have demonstrated the ability to cross the blood–brain barrier and inhibit the aggregation of amyloid-beta (Aβ) and hyperphosphorylated tau- the two key pathological markers of the disease.

Carbon dots as dual inhibitors of tau and amyloid-beta aggregation

The choice of precursor materials critically shapes the structural and functional properties of carbon dots (CDs), making it essential for application-specific design. Using Congo red as a CD precursor offers a promising strategy to enhance its blood–brain barrier (BBB) permeability while retaining its natural ability to inhibit both amyloid-beta (Aβ) and tau aggregation. This approach presents a novel and compelling direction for developing effective Alzheimer’s disease (AD) therapies.

Amphiphilic carbon dots for the inhibition of β-amyloid

Inhibition  of Aβ fibrillation can be achieved by enhancing the structural flexibility of Aβ monomers using hydrophilic carbon dots (CDs). In our study, the synthesized Y-CDs exhibited amphiphilic properties, combining a hydrophilic surface with abundant hydrophobic functionalities. The hydrophilic surface aids in preventing Aβ fibrillation, while the hydrophobic components facilitate blood–brain barrier (BBB) penetration via passive diffusion. Tested in cellular models, they mimic real CNS conditions and show strong potential as nontoxic, BBB-permeable nanocarriers for AD therapy. 

Figure 12.  (A) Y-CDs significantly reduced APP production in-vitro studies. (B) Quantification of APP mean fluorescence intensity (MFI) per cell following Y-CDs treatments.  (C) Quantification of the secreted β-Amyloid (Aβ) monomers in cell culture media following Y-CDs treatments.

Bone Infection Treatment

Our research group observed CDs prepared from carbon nanopowder could specifically target bones using zebrafish as a model. Since CDs have small size, high PL, water dispersity, nontoxicity, biocompatibility and abundant surface functional groups, CDs are promising drug nanocarrier to load drugs and deliver drugs in vivo, which can be tracked by their excellent PL. Therefore, we are trying to conjugate CDs with bone-related antibiotics and use zebrafish larvae as a model to examine whether the antibiotics could be efficiently delivered to the bones of zebrafish.

Figure 13. Bone-specific targeting and bioimaging with CDs synthesized from carbon nanopowder.

Photocatalytic Degradation of Environmental Contaminants

A microwave-assisted method was used to synthesize size-tunable carbon dots (CDs) with distinct photoluminescence (PL), structural features, and photocatalytic activity. Interestingly, PL emission did not correlate with size, suggesting a mechanism beyond quantum confinement. Diffuse reflectance spectroscopy revealed semiconductor behavior in one fraction (Fraction 3) with a narrow band gap of 2.04 eV. Smaller CDs (~2 nm) showed superior photocatalytic degradation of RhB and MB dyes under simulated sunlight, primarily via hole oxidation and superoxide radicals. Fraction 3 also achieved 70% degradation of p-nitrophenol and maintained stability over multiple cycles. This study is the first to report size-dependent photocatalytic activity in CDs, highlighting their potential as efficient, metal-free photocatalysts for environmental remediation.

Thermoelectric Effect of Carbon Dots

Cu₂Se is a promising thermoelectric (TE) material due to its earth-abundant elements and high mid-temperature performance. This study enhanced its TE efficiency by doping with gel-like carbon dots (G-CDs), synthesized via a rapid solvothermal method. Cu₂Se powders doped with 2 wt% G-CDs and spark plasma sintered achieved a record-high figure of merit (ZT) of 2.1 at 880 K—among the highest reported for this system. Structural analysis confirmed high purity, while the presence of quasi-spherical CDs, dense grain boundaries, and a compact Cu₂Se matrix boosted phonon scattering and electrical conductivity. This work demonstrates a scalable approach to G-CD doping and positions Cu₂Se as a strong candidate for future energy harvesting technologies.

Hybrid Rocket Fuel with Carbon Dots

This study investigated the combustion behavior of a novel hybrid rocket fuel composed of ABS and paraffin, enhanced with 1 wt% gel-like carbon dots (G-CDs). 3D-printed ABS molds were filled with neat and CD-loaded paraffin, while pure ABS served as a control. Ballistic tests using gaseous oxygen revealed that CD-loaded fuels achieved a combustion efficiency of 88% and a regression rate of 1.13 mm/s; improvements of 7% and 11%, respectively, over the non-doped paraffin blend. These enhancements were linked to increased particle entrainment due to reduced viscosity and improved thermal conductivity, supported by rheological, thermal, and SEM analyses.

Figure 16. The multi-step experimental strategy followed in this research.

Printing and Cosmetics

Due to the excellent PL, CDs have been applied in our group to make security, 3D printings and fingerprint. 3D printing was achieved through embedding CDs into a superabsorbent polymer. In addition, many photoluminescent cosmetic products have been developed such as photoluminescent nail polish, sun cream, and permanent hair colorant.