A Subcutaneously Injected SERS Nanosensor Enabled Long-term in Vivo Glucose Tracking

Yikun Huang,1

Yi Luo,2

Haomin Liu,3

Xiuling Lu,3

Jing Zhao2

Yu Lei1,4*Email

1Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, CT 06269, USA

2Department of Chemistry, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269, USA

3Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Storrs, CT 06269, USA

4Department of Chemical and Biomolecular Engineering, University of Connecticut, 191 Auditorium Road, Storrs, CT 06269, USA

Abstract

Diabetes is a major health problem around the world. In vitro enzyme-based glucose test strips have dominated the self-monitoring of blood glucose; however, the pain associated with fingerstick often deters patients from frequent monitoring. In this study, we report a subcutaneously injected surface enhanced Raman scattering (SERS) nanosensor to enable long-term in vivo glucose tracking. The glucose-responsive SERS nanosensor was prepared by self-assembling of a monolayer of 4-mercaptophenylboronic acid (MPBA) on gold nanoparticles (AuNPs). The aggregates of MPBA-functionalized AuNPs (MPBA-AuNPs) resulted in Raman signal enhancement of MPBA, and thus endowed MPBA-AuNPs serving as functional SERS nanosensor for glucose monitoring. After the demonstration of in vitro and ex vivo glucose detection, the glucose-responsive SERS nanosensor was subcutaneously injected into nude mice to investigate its ability in long-term in vivo glucose tracking. The trends obtained from glucose monitoring using a portable Raman probe in mice show a reasonable match with the ones derived from blood using a commercial glucose meter over a period of 60 days. The good biocompatibility of the subcutaneously injected MPBA-AuNPs nanosensor was also validated through histological analysis. All these features indicate that the as-prepared SERS nanosensor holds great potential in long-term glucose tracking.

A Subcutaneously Injected SERS Nanosensor Enabled Long-term in Vivo Glucose Tracking