On-Chip Surface-Based Detection with Nanohole Arrays

Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia, Canada
Analytical Chemistry (Impact Factor: 5.64). 07/2007; 79(11):4094-100. DOI: 10.1021/ac070001a
Source: PubMed


A microfluidic device with integrated surface plasmon resonance (SPR) chemical and biological sensors based on arrays of nanoholes in gold films is demonstrated. Widespread use of SPR for surface analysis in laboratories has not translated to microfluidic analytical chip platforms, in part due to challenges associated with scaling down the optics and the surface area required for common reflection mode operation. The resonant enhancement of light transmission through subwavelength apertures in a metallic film suggests the use of nanohole arrays as miniaturized SPR-based sensing elements. The device presented here takes advantage of the unique properties of nanohole arrays: surface-based sensitivity; transmission mode operation; a relatively small footprint; and repeatability. Proof-of-concept measurements performed on-chip indicated a response to small changes in refractive index at the array surfaces. A sensitivity of 333 nm per refractive index unit was demonstrated with the integrated device. The device was also applied to detect spatial microfluidic concentration gradients and to monitor a biochemical affinity process involving the biotin-streptavidin system. Results indicate the efficacy of nanohole arrays as surface plasmon-based sensing elements in a microfluidic platform, adding unique surface-sensitive diagnostic capabilities to the existing suite of microfluidic-based analytical tools.

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Available from: Reuven Gordon, Aug 12, 2014
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    • "Nanoplasmonic biosensors, which utilize plasmonic effects in engineered metal nanoparticles or nanostructures, have been proposed recently as a promising alternative to conventional SPR techniques, greatly broadening the range of potential technological applications [2]–[6]. Such nanoplasmonic biosensors eliminate the bulky prism-coupling geometry used in current SPR instruments, using instead a simple collinear transmission or reflection illumination geometry, which creates greater opportunities for sensor miniaturization, low-cost production, and integration with microfluidic platforms [7]. Scalability of the sensor footprint down to a few square micrometers also offers the possibility of massive multiplexing, which is difficult to achieve using previous SPR techniques [8]. "
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    ABSTRACT: Label-free biomolecular sensing is by far the most common and successful application area in the emerging field of nanoplasmonics. This review paper highlights the latest progress and achievements made in this area. Key aspects of the nanoplasmonic sensor development, including performance enhancement, efforts to increase multiplexing capacity, and the progress in sensor integration and miniaturization, are discussed.
    IEEE Photonics Journal 04/2014; 6(2):1-5. DOI:10.1109/JPHOT.2014.2311440 · 2.21 Impact Factor
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    • "SPR-based biosensors achieve higher sensitivities in different types of analyzes relative to other label-free sensors, such as in electrochemical [4], interferometric [5], and other systems [6] [7]. Also they present great potential for miniaturization [8], integration with microfluidics [9] and multiplexing detection capabilities [10]. Such characteristics are required for the implementation of lab-on-a-chip technologies [1]. "
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    ABSTRACT: Surface plasmon resonance platforms, based on arrays of nanoholes on gold films, were used to detect the binding of organic and biological molecules. Optical sensors were assembled using nanohole arrays with different resonance energies, tuned by adjusting the distance between the holes. A direct relationship between plasmon energy and bulk sensitivity to refractive index changes was verified experimentally. The highest sensitivity (ca. 463 nm/RIU) was obtained for the (1,0) SPP mode, excited on an array of nanoholes with 455 nm periodicity. Real-time monitoring of the specific biotin–streptavidin binding was also used to demonstrate the influence of transmitted light intensity and FWHM on the sensor performance.
    Sensors and Actuators 03/2013; 178:366-370. DOI:10.1016/j.snb.2012.12.090
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    • "In the last decade, many research groups have devoted their efforts to the study and development of label-free techniques such as Surface Plasmon Resonance (SPR), microcantilevers and semiconductor nanowires, for monitoring biological binding events [1] [2]. Among these techniques, SPR is probably one of the most studied, presenting many advantages including sensitivity , selectivity, speed and reliability in analysis, allowing real-time measurements, and placing additional emphasis on portability, miniaturization and on-site analysis [3] [4] [5] [6]. Thus, the literature describes works where SPR sensors have been applied in biomedical and biochemical research for the characterization and quantification of binding events. "
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    ABSTRACT: a b s t r a c t Surface plasmon resonance platforms based on laser inscribed azo polymer surface relief diffraction gratings were used to detect the binding of organic and biological molecules. Optical sensors were assem-bled to operate in transmission mode, resulting in a very simple setup. This new approach is observed to present a high sensitivity when compared to other systems, such as SPR-based biosensors using nanoholes. The corrugated surface provides a relatively large surface area and the improved sensitiv-ity to binding events is related to resonant plasmon enhancement on the surface relief grating. It was found that varying the periodicity from 400 to 410 nm does not improve efficiency, however changing the groove depth from 30 to 65 nm, resulted in a two-fold increase in sensitivity. An interesting result is that sensors with higher energy surface plasmons present higher sensitivity when compared to lower energy ones. This result can drive further studies toward improved surface plasmon-based sensors.
    Sensors and Actuators B Chemical 11/2012; 174:270-273. DOI:10.1016/j.snb.2012.08.026 · 4.10 Impact Factor
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