Hybridization-based DNA biosensing with a limit of detection of 4 fM in 30 s using an electrohydrodynamic concentration module fabricated by grayscale lithography

Inga Tijunelyte (1) , Jeffrey Teillet (1) , Paul Bruand (1) , Rémi Courson (2) , Aurélie Lecestre (2) , Pierre Joseph (1) , Aurélien Bancaud (1)

1 LAAS-MILE - Équipe Micro-Nanofluidique pour les sciences de la vie et de l’environnement
2 LAAS-TEAM - Service Techniques et Équipements Appliqués à la Microélectronique

Speeding up and enhancing the performances of nucleic acid biosensing technologies have remained drivers for innovation. Here, we optimize a fluorimetry-based technology for DNA detection based on the concentration of linear targets paired with probes. The concentration module consists of a microfluidic channel with the shape of a funnel in which we monitor a viscoelastic flow and a counter-electrophoretic force. We report that the technology performs better with a target longer than 100 nucleotides (nt) and a probe shorter than 30 nt. We also prove that the control of the funnel geometry in 2.5D using grayscale lithography enhances sensitivity by 100-fold in comparison to chips obtained by conventional photolithography. With these optimized settings, we demonstrate a limit of detection of 4 fM in 30 s and a detection range of more than five decades. This technology hence provides an excellent balance between sensitivity and time to result.

Domaines: Sciences de l'ingénieur [physics]; Matériaux; Micro et nanotechnologies/Microélectronique

Inga Tijunelyte, Jeffrey Teillet, Paul Bruand, Rémi Courson, Aurélie Lecestre, et al.. Hybridization-based DNA biosensing with a limit of detection of 4 fM in 30 s using an electrohydrodynamic concentration module fabricated by grayscale lithography. Biomicrofluidics, 2022, 16 (4), pp.044111. ⟨10.1063/5.0073542⟩. ⟨hal-03771547⟩