TY - JOUR

T1 - Terahertz probe of individual subwavelength objects in a water environment

AU - Masini, Luca

AU - Meucci, Sandro

AU - Xu, Jihua

AU - Degl'Innocenti, Riccardo

AU - Castellano, Fabrizio

AU - Beere, Harvey E.

AU - Ritchie, David

AU - Balduzzi, Donatella

AU - Puglisi, Roberto

AU - Galli, Andrea

AU - Beltram, Fabio

AU - Vitiello, Miriam S.

AU - Cecchini, Marco

AU - Tredicucci, Alessandro

PY - 2014/9

Y1 - 2014/9

N2 - Terahertz (THz) spectroscopy and imaging have been heralded for some time as potentially revolutionary techniques for biomedical applications. Label-free detection of molecules and recognition of molecular events are often mentioned as the most exciting possibilities. A crucial practical goal, however, is the ability to perform such measurements on tiny amounts of biological fluids or even on individual organic structures. Living cells, for instance, have diameters at most of some tens of micrometers, i.e. at least λ/10 even for few-THz radiation. Furthermore, all analyses relevant for a biological perspective must be performed in a water environment, which presents a strong absorption across the whole THz spectral range, severely limiting the penetration of the electromagnetic field. Here, it is shown how both issues can be overcome with a lab-on-a-chip approach based on a microfluidic platform coupled to a plasmonic antenna. Using a quantum cascade laser as THz illumination source, liquid volumes down to the picoliter range are probed, and direct operation on individual 10-μm diameter microparticles flowing in water is shown. The present demonstration opens the way to the development of THz biosensing of individual living cells and small probe volumes. A THz lab-on-a-chip device based on a microfluidic platform coupled to an integrated plasmonic antenna is shown. Using a quantum cascade laser as illumination source, liquid volumes down to the picoliter range are probed. A proof-of-concept experiment is performed in which single 10-μm diameter (∼ λ/10) microparticles flowing in water are identified and investigated. The present demonstration opens the way to the development of THz biosensing of individual living cells and small probe volumes.

AB - Terahertz (THz) spectroscopy and imaging have been heralded for some time as potentially revolutionary techniques for biomedical applications. Label-free detection of molecules and recognition of molecular events are often mentioned as the most exciting possibilities. A crucial practical goal, however, is the ability to perform such measurements on tiny amounts of biological fluids or even on individual organic structures. Living cells, for instance, have diameters at most of some tens of micrometers, i.e. at least λ/10 even for few-THz radiation. Furthermore, all analyses relevant for a biological perspective must be performed in a water environment, which presents a strong absorption across the whole THz spectral range, severely limiting the penetration of the electromagnetic field. Here, it is shown how both issues can be overcome with a lab-on-a-chip approach based on a microfluidic platform coupled to a plasmonic antenna. Using a quantum cascade laser as THz illumination source, liquid volumes down to the picoliter range are probed, and direct operation on individual 10-μm diameter microparticles flowing in water is shown. The present demonstration opens the way to the development of THz biosensing of individual living cells and small probe volumes. A THz lab-on-a-chip device based on a microfluidic platform coupled to an integrated plasmonic antenna is shown. Using a quantum cascade laser as illumination source, liquid volumes down to the picoliter range are probed. A proof-of-concept experiment is performed in which single 10-μm diameter (∼ λ/10) microparticles flowing in water are identified and investigated. The present demonstration opens the way to the development of THz biosensing of individual living cells and small probe volumes.

KW - Biochemical sensing

KW - Lab on a chip

KW - Plasmonic antennas

KW - Quantum cascade laser

KW - Terahertz

U2 - 10.1002/lpor.201300224

DO - 10.1002/lpor.201300224

M3 - Journal article

AN - SCOPUS:84906827390

VL - 8

SP - 734

EP - 742

JO - Laser and Photonics Reviews

JF - Laser and Photonics Reviews

SN - 1863-8880

IS - 5

ER -