title: Multiplexed detection and differentiation of the DNA strains for influenza A (H1N1 2009) using a silicon-based microfluidic system.
abstract: Pandemic influenza by the swine-origin influenza virus (H1N1 2009) has attracted considerable concern worldwide. A convenient and accurate diagnostic approach that can be deployed at the point of care, such as in a doctor's office or at an airport, is critical for disease control. Here we report the development of a silicon-based microfluidic system for subtype differentiation of the novel H1N1 2009 strain vs. the seasonal influenza A (FluA) strain. The proposed system included two functional modules: a multiplexed PCR module for amplification of nucleic acid targets and a multiplexed silicon nanowire (SiNW) module for sequence determination. The PCR module consisted of a microfluidic PCR chamber and an electrical controller to perform a multiplexed protocol that simultaneously enriched specific segments of both H1N1 and FluA strains (if present), with 10(4)-10(5) amplification efficiency. The PCR amplicon was subsequently denatured and transferred to the SiNW sensing module for a label-free, multiplexed detection. A control SiNW was implemented, for the first time, in order to eliminate background interference. The detection module demonstrated a 10× change in the magnitude of differential current when the target DNA was injected. Overall, the system achieved a sensitivity of 20-30 fg/μl for H1N1 and seasonal FluA nucleic acids in a 10 μl sample. The low sample consumption, high sensitivity and high specificity render it a potential point-of-care (POC) platform to help doctors reach a yes/no decision for infectious diseases.
authors.affiliation: Institute of Microelectronics, Agency for Science, Technology and Research, 11 Science Park Road, Singapore Science Park II, Singapore 117685, Singapore. kaoth@ime.a-star.edu.sg
authors.forename: Linus Tzu-Hsiang
authors.initials: LT
authors.lastname: Kao
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Shankar
authors.forename: Tae Goo
authors.initials: TG
authors.lastname: Kang
authors.forename: Guojun
authors.initials: G
authors.lastname: Zhang
authors.forename: Guang Kai Ignatius
authors.initials: GK
authors.lastname: Tay
authors.forename: Siti Rafeah Mohamed
authors.initials: SR
authors.lastname: Rafei
authors.forename: Charlie Wah Heng
authors.initials: CW
authors.lastname: Lee
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D016133:Polymerase Chain Reaction / Q000295:instrumentation*; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry
chemical_list: D004269:DNA, Bacterial; D012825:Silicon