Weisenstein C, Schaar D, Katharina Wigger A, Schäfer-Eberwein H, Bosserhoff AK, Haring Bolívar P. Ultrasensitive THz biosensor for PCR-free cDNA detection based on frequency selective surfaces.
BIOMEDICAL OPTICS EXPRESS 2020;
11:448-460. [PMID:
32010527 PMCID:
PMC6968760 DOI:
10.1364/boe.380818]
[Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 05/31/2023]
Abstract
THz technologies are a powerful tool for label-free detection of biomolecules. However, significant reduction of the lower detection limit is required to apply THz-sensors in biomedical diagnosis. This paper reports an ultrasensitive THz-biosensor based on asymmetric double split ring resonators (aDSRR) for the direct label- and PCR-free detection of DNA at physiologically relevant concentrations. We introduce selective functionalization and localized electric field concentration to enhance aDSRR sensitivity and specificity. The sensor characteristics are demonstrated using the human tumor marker MIA in cDNA samples produced from total RNA without PCR-amplification. Measurements of DNA samples with concentrations as low as 1.55 × 10-12 mol/l are presented.
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