(Invited) Real-Time Detection of Insulin Secreted By Pancreatic β-Cells Using Single-Walled Carbon Nanotube Sensors

Abstract

Quantification of insulin is essential for diabetes research in general, and for the study of pancreatic β-cell function in particular. Fluorescent single-walled carbon nanotubes (SWCNTs) find many applications as optical nanosensors for biomolecules, proteins, and enzyme, with real-time feedback on target analyte binding1–4. Herein, fluorescent SWCNT are used for the recognition and real-time quantification of insulin5. Two approaches for rendering the SWCNT sensors for insulin are compared, using surface functionalization with either a natural insulin aptamer with known affinity to insulin, or a synthetic lipid-PEG, both of which show a modulation of the emitted fluorescence in response to insulin. Although the PEGylated-lipid has no prior affinity to insulin, its response to insulin is more stable and reproducible compared to the insulin aptamer-SWCNTs. The SWCNT sensors successfully detect and quantify insulin secreted by β-cells within the complex environment of the conditioned media, and the results are found to be in agreement with an enzyme-linked immunosorbent assay5. This novel analytical tool for real time quantification of insulin secreted by β-cells provides new opportunities for rapid assessment of β-cell function.(1) Bisker, G.; Dong, J.; Park, H. D.; Iverson, N. M.; Ahn, J.; Nelson, J. T.; Landry, M. P.; Kruss, S.; Strano, M. S. Protein-Targeted Corona Phase Molecular Recognition. Nat. Commun. 2016, 7, 1–14.(2) Bisker, G.; Bakh, N. A.; Lee, M. A.; Ahn, J.; Park, M.; O’Connell, E. B.; Iverson, N. M.; Strano, M. S. Insulin Detection Using a Corona Phase Molecular Recognition Site on Single-Walled Carbon Nanotubes. ACS Sensors 2018, 8 (2), 367–377.(3) Amir, D.; Hendler-Neumark, A.; Wulf, V.; Ehrlich, R.; Bisker, G. Oncometabolite Fingerprinting Using Fluorescent Single-Walled Carbon Nanotubes. Adv. Mater. Interfaces 2021.(4) Wulf, V.; Slor, G.; Rathee, P.; Amir, R. J.; Bisker, G. Dendron-Polymer Hybrids as Tailorable Coronae of Single-Walled Carbon Nanotube. ChemRxiv 2021. https://doi.org/10.26434/ChemRxiv.14452785.V1.(5) Ehrlich, R.; Hendler‐Neumark, A.; Wulf, V.; Amir, D.; Bisker, G. Optical Nanosensors for Real‐Time Feedback on Insulin Secretion by Β‐Cells. Small 2021, 17 (30), 2101660.