Nanomaterial-based sensors ("nanosensors") are attractive detection tool to detect multiple disease biomarkers swiftly and at point-of-care. These nanosensors make use nanometer-sized particles with unique physical, optical, and electrical properties to induce enhanced output signals in response to the detection and/or changes in concentrations of analytes. In this talk, I will discuss my group's effort in using one of the nanosensors, surface-enhanced Raman scattering (SERS) nanosensors for various biomedical applications. SERS utilizes metallic nanoparticles such as Ag and Au to harness incoming light excitation, concentrate surface plasmon resonances, and boost the Raman vibrational signatures of biomarkers for ultrasensitive detection. Firstly, I will discuss various SERS platform fabrication strategies to bestow desirable chemoselectivity and increase target analyte/biomarker affinity to achieve higher detection sensitivity and selectivity. I will also highlight various emerging research strategies which utilize machine learning algorithms for rapid on-site prediction of disease infection. Specifically, how chemometrics and machine learning algorithms can transform the assimilation and interpretation of complex spectral data in biological samples by discerning more patterns hidden within the data, to achieve high throughput data analysis, sensitivity, and disease prediction. Collectively, these advances underscore the potential of SERS nanosensors and hybrid analytical strategies to address longstanding challenges in biomarker sensing and to accelerate innovation in biomedical diagnostics.

Accessible and sustainable diagnostics are essential for rapid pandemic response, personalized home care, and long-term management of conditions such as cancer and neurodegenerative diseases. We present microfluidic platforms enhanced with nanomaterials--from metallic nanoparticles to 2D graphene--enabling lateral flow assays, wearable devices, and standalone sensors. These scalable, eco-conscious technologies offer high sensitivity and adaptability, addressing urgent global health needs at the point of care.

The microbiome-gut-brain axis (MGBA), has emerged as an incredibly important, but complex, part of human physiology. Dysregulation or disruption of the MGBA is implicated in a host of pathologies that affect brain and gut (e.g. Autism Spectrum disorder, Crohn's disease) but also whole body disorders where inflammation and metabolism are affected (e.g. diabetes). Physiologically relevant in vitro human models, as well as advanced tools to study in vivo animal models, are urgently required to elucidate mechanisms in MGBA. Until recently, the majority of studies that seek to explore the mechanisms underlying the microbiome-gut-brain axis relied almost exclusively on animal models. Despite the great progress made with these models, various limitations, including ethical considerations and interspecies differences that limit the translatability of data to human systems, pushed researchers to seek for alternatives. In this talk I'll discuss a new generation of electronic tools, based on conducting polymers, for understanding the gut-brain-microbiome axis. First, I'll discuss our progress towards generating a complete platform of the human microbiota-gut-brain axis with integrated monitoring and sensing capabilities. Bringing together principles of materials science, tissue engineering, 3D cell biology and bioelectronics, we are building advanced models of the GI, with integrated real-time and label-free electronic monitoring, aiming to elucidate the role of microbiota in the gut-brain axis communication. Recent integration of patient derived microbiome and gut biopsy derived epithelial organoids makes the models more human relevant. Second, I'll discuss conformable electronic devices we've developed for both ex-situ measurements of GI tissue from rats in organ baths as well as validation in vivo experiments in live rats. Integration of fluidics is an ongoing concern. Our device platforms ultimately aim to allow highly sensitive monitoring of impedance of the tissue (as an indicator of gut health) as well as the enteric nervous system.

A full understanding of the molecular basis of diseases depends on the development of molecular probes able to recognize disease targets of interest. Until very recently, such tools have been absent from the clinical practice of medicine. The newest molecular probe, and one that holds great promise, is a new class of designer nucleic acids, termed aptamers, which are single-stranded DNA/RNA able to recognize specific targets, such as single proteins and even small molecules. Recently, we applied a simple, fast and reproducible cell-based aptamer selection strategy called Cell-SELEX which uses whole, intact cells as the target for aptamer selection. This selection process then generates multiple aptamers for the specific recognition of biological cells, but without the need for prior knowledge about the signature of target cell-surface molecules. The selected aptamers have dissociation constants in the nanomolar to picomolar range. Thus far, we have selected aptamer probes for many different diseases, and used them to carry out studies at the vanguard of biomedical science, including ultrasensitive detection of tumors, molecular imaging, targeted drug delivery, cancer biomarker discovery, and, most critically, molecular subtyping of diseases in real clinic. Taken together, these molecular level tools form a solid scientific platform from which to pursue advanced studies in molecular medicine. We will report our most recent progress in this exciting research and development area, especially in clinic trials.