Label-free quantitative DNA detection using the liquid core optical ring resonator

Department of Biological Engineering, 240D Bond Life Sciences Center, University of Missouri-Columbia, Columbia, MO 65211, USA.
Biosensors & Bioelectronics (Impact Factor: 6.45). 03/2008; 23(7):1003-9. DOI: 10.1016/j.bios.2007.10.005
Source: PubMed

ABSTRACT We demonstrated quantitative real-time label-free detection of DNA sequences using the liquid core optical ring resonator (LCORR) sensor. The LCORR is a recently developed sensing platform that integrates microfluidics and photonic sensing technology with low detection limit and sub-nanoliter detection volume. We analyzed experimentally and theoretically the LCORR response to a variety of DNA samples that had different strand lengths (25-100 bases), number of base- mismatches (1-5), and concentrations (10 pM to 10 microM) to evaluate the LCORR sequence detection capability. In particular, we established the linear correlation between the LCORR sensing signal and the molecule density, which allows us to accurately calculate the molecule density on the surface. It is found that the probe surface coverage was 26-51% and the extent of hybridization was 40-50%. The titration curve for 25-base probe and 25-base target DNA yields a dissociation constant of 2.9 nM. With a 37.1 nm/RIU LCORR, detection of 10 pM bulk DNA concentration was demonstrated. The mass detection limit was estimated to be 4 pg/mm(2), corresponding to a density of 10(10) molecules/cm(2) on the surface. We also showed that the LCORR was sensitive enough to differentiate DNA with only a few base-mismatches based on the raw sensing signal and kinetic analysis. Our work will provide important insight into the light-DNA interaction at the ring resonator surface and lay a foundation for future LCORR-based DNA label-free microarray development.

  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study we show an optical biosensor concept, based on elastic light scattering from sapphire microspheres. Transmitted and elastic scattering intensity of the microspheres (radius 500 μm, refractive index 1.77) on an optical fiber half coupler is analyzed at 1510 nm. The 0.43 nm angular mode spacing of the resonances is comparable to the angular mode spacing value estimated using the optical size of the microsphere. The spectral linewidths of the resonances are in the order of 0.01 nm, which corresponds to quality factors of approximately 105. A polydopamine layer is used as a functionalizing agent on sapphire microspherical resonators in view of biosensor implementation. The varying layer thickness on the microsphere is determined as a function of the resonance wavelength shift. It is shown that polymer functionalization has a minor effect on the quality factor. This is a promising step toward the development of an optical biosensor.
    Sensors and Actuators A Physical 02/2015; 222. DOI:10.1016/j.sna.2014.11.024 · 1.94 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Silicon photonics using microdisk and microring resonators are finding technologically important applications from telecommunications and on-chip optical interconnects to optofluidics and biosensing. Silicon-based microresonators that partially confine light by total internal reflection are versatile device structures which are highly wavelength-selective, reconfigurable via various refractive index tuning mechanisms, micrometer-scale footprint, and readily in/out-coupled with integrated waveguides. In this paper, we will highlight our latest progress in silicon photonics using microdisk and microring resonators for on-chip optical interconnects, optofluidics and biosensing applications including the experimental demonstrations of: (i) optical time delay and advance using silicon microring resonators integrated with pi- n diodes; (ii) photocurrent spectroscopy of microdisk resonators using two-photon-absorption induced photocarriers; (iii) optical trapping and transporting of microparticles using a water-clad silicon nitride microring resonator; and (iv) coupled microdisk resonator optical waveguide-based refractive index sensors.
    Conference on Laser Resonators and Beam Control XIII; 02/2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: We investigate an application case study of a phase sensitive surface plasmon resonance (SPR) biosensor based on Mach–Zehnder configuration for efficient targeted drug screening, where calculating reaction kinetic constants, inhibition effect and cytotoxicity analysis are three key factors in the evaluation. As a typical targeted drug, cetuximab is selected in the measurements assisted by the phase SPR biosensor with a sensitivity of 10−6 in terms of refractive index unit (RIU) and stability of 6 × 10−7 RIU in 80 min. The reaction kinetic constants of cetuximab binding to epidermal growth factor receptor (EGFR) are found as: kd (dissociation constant) = 1.75 ± 0.29 × 10−3 S−1, kD (equilibrium dissociation constant) = 4.19 ± 0.58 nM. The results of inhibition effect analysis show that cetuximab can block EGFR binding to its two ligands, epidermal growth factor (EGF) and EGFR-transforming growth factor α (TGF-α). This effect has been tested in three cell lines of lung adenocarcinoma, colon cancer and breast cancer. Comparing to other conventional methods, we find that the phase SPR biosensor can determine the cell sensitivity to cetuximab in just 4 h. As a label-free, real-time, high sensitivity and stability biosensor, the phase SPR biosensor is a potential optical technique for targeted drug screening and analysis of cell resistance to drugs with comparative advantages.
    Sensors and Actuators B Chemical 03/2015; 209. DOI:10.1016/j.snb.2014.11.134 · 3.84 Impact Factor


1 Download
Available from