Multilayer Porous Hydrogel for Robust Sensing of Macromolecules with Florescent Carbon Nanotube Sensors

Technology      

Individually dispersed, semiconducting single-walled carbon nanotubes (SWNT) exhibit near-infrared (nIR) photoluminescence (PL). Previously, selective modulation of SWNT PL has been demonstrated in response to glucose, divalent metal cations, DNA hybridization, and reactive oxygen species. The use of SWNTs as nIR optical sensors has potential utility in clinical or medical settings because nanotube PL occurs in a region of the electromagnetic spectrum in which blood and tissue is particularly transparent. Additionally, SWNTs do not photobleach and are ideally suited for long-term sensing applications. Hydrogels are cross-linked polymer matrices that can swell in the presence of water and are attractive materials for biological applications due to their biocompatibility and structural properties. They have been proposed as scaffolds for tissue engineering and have been fabricated to respond, by expanding or contracting, to specific stimuli for a number of drug delivery and sensing applications. Hydrogels have previously been fabricated with single-walled and multi-walled carbon nanotubes embedded; however, there exists no demonstration of SWNT PL inside a hydrogel matrix. The current invention proposes a hydrogel-based sensor utilizing SWNTs that can be advantageous for in vivo applications due to the inherent biocompatibility of the hydrogel matrix, and if the matrix is non-biodegradable, it would also prevent nanotube leaching.  

Problem Addressed

Other biological sensors are not transparent through blood and tissues and are more susceptible to photobleaching. This device allows for inserting stable photoluminescent SWNTs into hydrogels which can then be embedded into biological tissues for stable long term in vivo sensing.  

Advantages      

• Long-term sensing
• In vivo sensing applications
• Biocompatibility
• Avoids SWNT leeching into the body if the hydrogel matrix is non-biodegradable.  

Publications

Modulation of Single-Walled Carbon Nanotube Photoluminescence by Hydrogel Swelling. ACS Nano 3, no. 2 (2009): 338-344.