232. MRI-Based Glucose Assay Using Magnetic Nanoparticle Sensors
Satoshi Okada, Satoko Takayasu, Akira Sumiyoshi, Ichio Aoki, Hiroyuki Nakamura; Analytical Sciences; (2021); DOI: 10.2116/analsci.21P08210.2116/analsci.21P082 (open access)
Glucose sensors for NMR relaxometry and magnetic resonance imaging (MRI) can be used for direct measurement of glucose in turbid biological specimens. Here, we proposed a magnetic glucose sensor based on superparamagnetic iron oride (SPIO) nanoparticles conjugated to a mannopyranoside derivative and concanavalin A (ConA). The binding of mannopyranoside groups to SonA produced a nanoparticle cluster that was dissociated by competitive binding of glucose to ConA, resulting in changes in the transverse relaxation time (T2) in a glucose-dependent manner. The sensor gave rise to significant T2 changes in physiological glucose levels of 3-8 mM at a nanoparticle concentration of 0.5 nM. Significant T2 responses were observed within 6 min of 5 mM glucose detection. Sensor-based MRI by a benchtop 1 tesla scanner permitted a measurement of multiple samples within 8 min. These results demonstrate that the relaxometric glucose sensor could lead to high throughput diret assay of blood samples by using a compact MRI scanner for point-of-care testing.