Fluorescence Biosensing in Nanopores

Jan Karolin, Dalibor Panek, Alexander MacMillan, Olaf Rolinski, David Birch

Research output: Chapter in Book/Report/Conference proceedingConference contribution book


Hydrated nanopores offer a unique environment for studying biological molecules under controlled conditions and fabricating sensors using fluorescence. Silica nanopores for example are non-toxic, biologically and optically compatible with protein, and can be easily synthesized to entrap protein and exclude potentially interfering macromolecules, while transmitting analytes of interest. A well known problem when polymerizing orthosilicates to fabricate silica sol-gel nanopores is the release of alcohol, which denatures proteins. We will describe how using the fluorescence of PRODAN (6-propionyl-2-(N,N-dimethylamino)naphthalene) to monitor methanol generated during polymerization has helped define a protocol with enhanced biocompatibility. The improved biocompatibility of sol-gel nanopores synthesized using tetramethyl orthosilicate (TMOS) has been demonstrated by preserving the unstable native trimer form of allophycocyanin (APC) for up to 500 Hrs without the need to covalently binding the subunits together. This has enabled the observation of native APC trimer by means of its fluorescence in a pore down to the single molecule level. In this paper we demonstrate how PRODAN and another polarity sensitive dye, 9-diethylamino-5H-benzo[alpha]phenoxazine-5-one, Nile red (NR) report on pore polarity and successfully extend protein encapsulation to nanochannels of alumina (Al2O3). Improved biocompatibility of nanopores has potential impact in nanomedicine where the ability to study single biomolecules is a primary goal as it underpins our understanding of disease pathology and therapeutics at the most fundamental level. In sensing also the advantages of nanopore isolation of metabolite-specific protein for detecting non-fluorescent metabolites has been demonstrated. Similar approaches can in principle be developed for both single-molecules and lab-on-a-chip sensors.
Original languageEnglish
Title of host publicationEngineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE
ISBN (Print)9781424432967
Publication statusPublished - Sep 2009
EventEngineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE - Minneapolis
Duration: 1 Jan 1900 → …


ConferenceEngineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE
Period1/01/00 → …


  • hydrated nanopores
  • biological molecules
  • fluorescence
  • silica nanopores
  • polymerizing orthosilicates
  • biocompatibility
  • biosensors
  • molecular biophysics
  • nanobiotechnology
  • nanostructured materials
  • optical sensors
  • proteins
  • silicon compounds
  • sol-gel processing
  • solvation

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