Conjugated Polymers

The optical bioimaging activities are at the forefront of innovation, combining advanced light-based techniques with engineered contrast agents and functional materials to enable sensitive, specific, and non-invasive visualization of biological systems. A central focus lies in fluorescence imaging, where the lab designs and utilizes novel organic fluorophores and conjugated polymer nanoparticles (CPNs) with enhanced brightness, photostability, and biocompatibility. These probes are tailored for targeted imaging of cancerous lesions, particularly in colorectal and breast cancer models, allowing real-time monitoring of tumor development, cellular uptake, and therapeutic response. Sophisticated in vitro and in vivo fluorescence systems are employed to study disease progression, biomarker dynamics, and drug distribution, often in small animal models. This work is supported by deep expertise in structure-property relationship studies, enabling the rational design of materials for optimal emission characteristics and bio-interaction profiles.

Complementing fluorescence, the lab applies photoacoustic imaging (PAI) to achieve deep-tissue visualization with high contrast and spatial resolution. This technique exploits the photoacoustic effect, where pulsed light absorbed by tissues or contrast agents generates ultrasound waves, providing hybrid optical-acoustic information. PAI is especially powerful for imaging tumor vasculature, hypoxia, and hemoglobin oxygenation, enabling functional assessments critical for cancer theranostics and cardiovascular research. Furthermore, ultrasound imaging is used both independently and in tandem with PAI to provide anatomical context and track physiological changes in real time. The lab also employs micro-Raman spectroscopy, a label-free, chemically specific technique that captures the intrinsic vibrational signatures of biomolecules. This allows for the discrimination of healthy and diseased tissues, monitoring of biochemical changes, and classification of tumor types at the single-cell level. Together, these complementary modalities are integrated into multimodal imaging platforms, offering comprehensive spatial, molecular, and functional insights. The laboratory’s approach not only enhances preclinical diagnostics but also serves as a technological foundation for clinical translation of precision imaging tools tailored to complex diseases.

The biosensors activities center on the development of next-generation organic electronic devices, particularly organic photodetectors (OPDs) and organic phototransistors (OPTs), as highly sensitive, flexible, and low-cost platforms for biomedical sensing. These devices are designed to detect optical signals (from endogenous or exogenous sources) and convert them into electrical outputs, enabling the real-time monitoring of biological events relevant to cancer diagnosis, cardiovascular health, and point-of-care diagnostics.

Organic Photodetectors (OPDs) for Biosensing

OPDs in the lab are engineered to operate across the visible to near-infrared (NIR) spectral range, allowing detection of weak optical signals in biological tissues, even under low-light conditions. These devices are fabricated using solution-processable conjugated polymers and small molecules, with tunable energy levels and absorption profiles tailored for specific bioanalytes or imaging wavelengths. The lab is actively working on integrating OPDs into biocompatible substrates and flexible electronics, enabling wearable or implantable biosensors. For cancer applications, OPDs are used to detect fluorescence signals from labeled biomarkers or autofluorescent metabolic indicators, with a focus on early-stage lesion identification and real-time intraoperative guidance. In cardiovascular monitoring, OPDs are being developed to sense oxygenation levels and blood flow dynamics through detection of reflected or transmitted optical signals in photoplethysmography (PPG) and pulse oximetry configurations.

Organic Phototransistors (OPTs) for Amplified Signal Detection

The lab also develops organic phototransistors, which offer intrinsic signal amplification and higher sensitivity compared to OPDs. These three-terminal devices can transduce very low light levels—such as those emitted from weakly fluorescent cancer biomarkers—into strong electrical signals with minimal noise. OPTs are fabricated using ambipolar or unipolar conjugated semiconductors, with careful engineering of the channel material, dielectric interface, and contact electrodes to maximize performance and stability under physiological conditions. In cancer biosensing, OPT-based platforms are being explored for detecting optical signals from molecular probes or nanoparticles that target specific cancer cell receptors, enabling high-contrast and selective tumor detection. For cardiovascular applications, the lab is investigating OPTs for continuous, high-fidelity detection of heartbeat, vascular stiffness, and photonic biosignals associated with endothelial function or inflammation.