Electric chips for rapid detection and quantification of nucleic acids
2004 (English)In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 19, no 6, 537-546 p.Article in journal (Refereed) Published
A silicon chip-based electric detector coupled to bead-based sandwich hybridization (BBSH) is presented as an approach to perform rapid analysis of specific nucleic acids. A microfluidic platform incorporating paramagnetic beads with immobilized capture probes is used for the biorecognition steps. The protocol involves simultaneous sandwich hybridization of a single-stranded nucleic acid target with the capture probe on the beads and with a detection probe in the reaction solution, followed by enzyme labeling of the detection probe, enzymatic reaction, and finally, potentiometric measurement of the enzyme product at the chip surface. Anti-DIG-alkaline phosphatase conjugate was used for the enzyme labeling of the DIG-labeled detection probe. p-Aminophenol phosphate (pAPP) was used as a substrate. The enzyme reaction product, p-aminophenol (pAP), is oxidized at the anode of the chip to quinoneimine that is reduced back to pAP at the cathode. The cycling oxidation and reduction of these compounds result in a current producing a characteristic signal that can be related to the concentration of the analyte. The performance of the different steps in the assay was characterized using in vitro synthesized RNA oligonucleotides and then the instrument was used for analysis of 16S rRNA in Escherichia coli extract. The assay time depends on the sensitivity required. Artificial RNA target and 16S rRNA, in amounts ranging from 10(11) to 10(10) molecules, were assayed within 25 min and 4 h, respectively.
Place, publisher, year, edition, pages
2004. Vol. 19, no 6, 537-546 p.
electric biochips, sandwich hybridization, magnetic bead, redox recycling, 16S rRNA, labeled oligonucleotide probes, in-situ accessibility, escherichia-coli, ribosomal-rna, dna, hybridization, arrays, immobilization, amplification, technology
IdentifiersURN: urn:nbn:se:kth:diva-23118DOI: 10.1016/s0956-5663(03)00273-2ISI: 000188504900003ScopusID: 2-s2.0-0347626208OAI: oai:DiVA.org:kth-23118DiVA: diva2:341816
QC 20100525 QC 201110312010-08-102010-08-102011-10-31Bibliographically approved