In vivo Real-time Biosensor: Convergence of Electroanalytical Chemistry, Nanotechnology and Bioengineering

Presenter: Kaiyu Fu, Department of Radiology and Electrical Engineering, Stanford University

The emerging biosensing devices largely extend our capability to measure and monitor the biomolecules in living organisms. Yet most commercially available detection platforms are ether simplified for a handful of abundant molecules in vivo, e.g., glucose and electrolytes, or designed with time-consuming pretreatment procedures for targets with a lower concentration. There is an urgent quest to integrate the advancement of analytical chemistry and nanotechnology to solve the long-existing problems for biodetection.

In this talk, I will first present a novel electrochemical detection platform that consists of high-density nanoscale electrodes, viz. nanopore electrode array (NEA), for ultrasensitive biomolecule detection. Through a robust fabrication method to achieve nanopores with embedded electrodes, I will explore how electron transfer and ion transport are coupled in the nanostructures for the m\t (ass-limited samples. Next, I will present a real-time sensing technology to measure biomolecules in live animals based on the above-mentioned nanoporous electrode. In the first example, I will discuss an implantable NEA drug sensor to collect tissue-based pharmacokinetics. So far, the efficacy and safety of chemotherapy are measured based on blood samples. This NEA drug sensor can continuously measure the concentrations of the chemotherapy drug at multiple tumor sites in a rodent model. Due to the tumor microenvironment heterogeneity, it demonstrates apparent differences in pharmacokinetics relative to the circulation that could meaningfully affect treatment. Last, I will introduce the second example that an implantable NEA neurochemical sensor can continuously measure the neurotransmitters in the cerebrospinal fluid of the brain. This NEA neurochemical sensor is designed on a flexible substrate with multiple sensing elements for chronic recording at different brain regions. In addition, the whole system is integrated with a wireless module as a potentially cable-free device to track the behaviors of freely moving animals associated with the detection of neurochemical signals. Overall, this talk will depict a generalized approach to access in vivo real-time biochemical information for future clinical applications.