Highly sensitive and selective sugar detection by terahertz nano-antennas

TL;DR

This paper introduces a highly sensitive and selective terahertz nano-antenna sensor capable of detecting and discriminating various carbohydrate molecules at low concentrations, outperforming previous methods.

Contribution

The development of a nano-slot-antenna array-based sensing chip operating in the terahertz range for carbohydrate detection and discrimination is a novel approach.

Findings

Effective detection of carbohydrates at low concentrations.

High selectivity in distinguishing different carbohydrate molecules.

Successful application to real market beverages.

Abstract

Molecular recognition and discrimination of carbohydrates are important because carbohydrates perform essential roles in most living organisms for energy metabolism and cell-to-cell communication. Nevertheless, it is difficult to identify or distinguish various carbohydrate molecules owing to the lack of a significant distinction in the physical or chemical characteristics. Although there has been considerable effort to develop a sensing platform for individual carbohydrates selectively using chemical receptors or an ensemble array, their detection and discrimination limits have been as high in the millimolar concentration range. Here we show a highly sensitive and selective detection method for the discrimination of carbohydrate molecules using nano-slot-antenna array-based sensing chips which operate in the terahertz frequency range. This THz metamaterial sensing tool recognizes various types of carbohydrate molecules over a wide range of molecular concentrations. Strongly localized and enhanced terahertz transmission by nano-antennas can effectively increase the molecular absorption cross sections, thereby enabling the detection of these molecules even at low concentrations. We verified the performance of nano-antenna sensing chip by both THz spectra and images of transmittance. Screening and identification of various carbohydrates can be applied to test even real market beverages with a high sensitivity and selectivity.