Abstract
During growth, tumor spheroids develop gradients of glucose. In this work, we unveiled real time glucose gradient in tumor spheroid using Confocal Raman Spectroscopy. For sensor preparation, 50 nm silver nanoparticle is conjugated with Raman based dye, mercapto-phenylboronic acid(MPBA). The sensor approach a detection limit of 1 mM and dynamic range from 1-100 mM of glucose. MPBA -glucose bonding being reversible, helps for continuous measurement inside 3D microenvironment. Sensors are mixed with co-cultured cells(colon cancer and fibroblast) and seeded in 3D culture chip for spheroid formation. Raman measurement showed an increased glucose concentration from center to surface of spheroid.