Terahertz spectroscopy for bacterial detection: opportunities and challenges

Abstract

The demand for advanced bacterial detection tools is continuously increasing, promoted by its significant benefits in various applications. For instance, in the medical field, these tools would facilitate decision making about more tailored therapies once the infection source has been identified. In the past few years, terahertz (THz = 10(12) Hz) spectroscopy has also shown potential as a novel bacterial detection modality due to its unique advantages. Impressive breakthroughs have been achieved in this field related to bacterial component characterization, spore identification, and cell detection. However, some intrinsic limitations and technical bottlenecks have led to some debates about the practicability of its clinical adoption. In this review, we summarize the progress achieved in this field and discuss some challenges and strategies for future implementation of practical applications.

Terahertz Sensing Based on Metasurfaces

“…[4,5,[7][8][9][10]15,[22][23][24] Nevertheless, a challenge still open is how to achieve reliable sensing when the measured sample amount is very small. These properties have given rise to a powerful research line, and indeed, the list of biological applications of THz is extensive and in continuous development so the interested reader is referred to some recent books and reviews devoted to the topic.…”

“…These properties have given rise to a powerful research line, and indeed, the list of biological applications of THz is extensive and in continuous development so the interested reader is referred to some recent books and reviews devoted to the topic. [4,5,[7][8][9][10]15,[22][23][24] Nevertheless, a challenge still open is how to achieve reliable sensing when the measured sample amount is very small. [25] In this situation, the substance under test simply does not interact sufficiently with the electromagnetic waves inducing negligible changes in the response and making detection extremely difficult or even impossible with conventional techniques.…”

A Comprehensive Review on Food Applications of Terahertz Spectroscopy and Imaging

“…Molecular methods are also complex, but are fast and have LOD of several genome equivalents. Mass spectroscopy techniques are reagent‐free, very fast, and simple, with an LOD of between 10 5 and 10 6 CFU/mL (Yang, Yang, Luo, & Fu, ). None of these methods can detect microorganisms inside a package or differentiate between dead and living bacteria.…”

Nanoantenna enhanced terahertz interaction of biomolecules

“…Enhancement (E) 0 > 100 nm 100 -10 nm 10 -1 nm 10 1 10 2 10 3 < 1 nm w=1 m E=300 [39] w=100 nm E=1000 [89] w=70 nm E=1000 [34] w=20 nm E=1200 [36] w=2 nm E=1200 [21] w=9 nm E=180 [37] w=1.5 nm E=2000 [16] w=10 m E=30 [33] is a non-invasive and one of the most widely used technique in biosensing 80,[83][84][85][86][87] because the THz-spectra are less energetic (about a few milli-electronvolts) lies in the characteristic vibration frequency regime of proteins and DNA molecules. Terahertz nanoantennas provide us label-free and ultra-sensitive sensing of molecules 88,89 and biomolecules 37,81,[90][91][92][93][94] as the nanoantennas focus the THz waves into an extremely confined volume where we can place our analytes at very low concentrations.…”