(231c) Enzyme-Conjugated Nanosensors with a Tunable Detection Limits for Small Bio-Molecule Monitoring

Analyte monitoring in biological settings is crucial for medical providers and researchers in numerous fields. However, the current methods of analyte detection can be limited in biocompatibility, their ability to measure continuously, monitor spatially, or provide non-invasive online monitoring in vivo. Nanosensors are a next generation sensor technology that hold the possibility of analyte monitoring with none of these limitations. Their miniaturized nature allows them to provide analyte information through a three dimensional space while their light-based information transfer makes them ideal for continuous monitoring. Therefore, nanosensor technology development can lead to more accurate medical diagnoses and disease management and allow for cell culture analysis in ways not currently possible. However, functionalization of nanosensors is necessary to expand the range of accessible analytes. In this work, we develop a platform of enzyme-linked nanosensors (ELiNS) for glucose detection. The platform consists of a biotin/avidin based conjugation approach to attach the enzyme glucose oxidase to oxygen-detecting nanosensors. We show that the dynamic range can be shifted by adjusting amount of enzyme associated with each nanosensor, providing an easy tool to produce an optimized sensor for multiple applications. We also show that the enzyme/nanosensor ratio can be easily adjusted by controlling the amount of biotin-functionalized lipids on the nanosensor surface. Furthermore, we show that the specificity of the sensor can be easily adjusted by swapping the enzyme for a different type of oxidase enzyme, making the technique ideal for building a suite specific towards other small biomolecules such as lactic acid.