Label-free aptamer sensor based on silicon microring resonators

• Published in: Sensors and actuators. B, Chemical Vol. 176; pp. 552 - 559
• Main Authors: Park, Mi Kyoung, Kee, Jack Sheng, Quah, Jessie Yiying, Netto, Vivian, Song, Junfeng, Fang, Qing, La Fosse, Eric Mouchel, Lo, Guo-Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2013
• Subjects: air; antigens; Aptamer sensor; Arrays; detection limit; DNA; Human; humans; immunoglobulin E; Immunoglobulins; Label-free detection; oligonucleotides; Optical sensor; polycyclic aromatic hydrocarbons; Resonators; Sensor arrays; Sensors; Silicon; Silicon biophotonics; Silicon microring resonator; Thrombin; Aptamer sensor; Optical sensor; Silicon microring resonator; Label-free detection; Silicon biophotonics
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2012.08.078

We present a label-free DNA aptamer sensor based on silicon microring resonators for the detection of human immunoglobulin E (IgE) and human thrombin. An array of silicon resonators consisting of three sensor microrings and one reference microring was fabricated and its surface sensitivity, detection limit and repeatability were investigated by the deposition of poly (sodium-4-styrenesulfonate) (PSS) and poly (allylamine hydrochloride) (PAH) multilayers. The surface sensitivity and the limit of detection of the fabricated sensor ring are found to be 0.35nm/ngmm−2 and 26pg/mm2 in air and 0.24nm/ngmm−2 and 38pg/mm2 in water, respectively. We have demonstrated quantitative, sensitive and specific detection of human IgE and thrombin with aptamer modified silicon microring resonators over a broad range of antigen concentrations. The sensor array showed an experimental detection limit of 33pM and 1.4nM for IgE and thrombin, respectively. Multiplexing was also performed successfully with a mixed solution of IgE and thrombin and proved the sensor to be highly specific. We believe our silicon microring resonator technology in combination with aptamers offers a low cost solution for various point-of-care applications.