On-Chip Glucose Sensing at Terahertz Frequencies

TL;DR

This paper presents a novel on-chip terahertz sensor for detecting D-glucose by measuring frequency-dependent changes in transmission, demonstrating label-free detection at specific THz resonances with potential for sensing other materials.

Contribution

The work introduces an on-chip THz sensing platform for D-glucose detection, combining experimental measurements with simulations, advancing miniaturized biosensing technologies.

Findings

Detection of D-glucose at 1.42 THz and 2.07 THz resonances

Alignment of experimental results with simulations and literature

Verification of on-chip THz sensing capability

Abstract

This paper demonstrates an on-chip anhydrous D-glucose sensor based using a coplanar stripline (CPS) on a thin (1 um) silicon nitride membrane at terahertz (THz) frequencies. A thin layer (~10 um) of D-glucose was placed in close proximity to the CPS and the transmission response was measured using a modified THz-TDS setup. The D-glucose introduces frequency-dependent changes to the effective permittivity of the CPS resulting in a modified spectral response at the receiver. Measurement results show absorption signatures at 1.42 THz and 2.07 THz corresponding to the first two significant resonances beyond 1 THz for D-glucose allowing for label-free detection. The frequency-dependent attenuation coefficient was estimated by simulation for several D-glucose layer thicknesses using a modified Lorentz model. Measurement results align with simulations and other literature that use free-space THz radiation. This work verifies on-chip THz sensing of D-glucose and presents a pathway towards on-chip sensing of other materials at THz frequencies.