Frequency Domain Detection of Biomolecules Using Silicon Nanowire Biosensors

Laboratory of Advanced Materials, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China.
Nano Letters (Impact Factor: 13.59). 08/2010; 10(8):3179-83. DOI: 10.1021/nl1020975
Source: PubMed


We demonstrate a new protein detection methodology based upon frequency domain electrical measurement using silicon nanowire field-effect transistor (SiNW FET) biosensors. The power spectral density of voltage from a current-biased SiNW FET shows 1/f-dependence in frequency domain for measurements of antibody functionalized SiNW devices in buffer solution or in the presence of protein not specific to the antibody receptor. In the presence of protein (antigen) recognized specifically by the antibody-functionalized SiNW FET, the frequency spectrum exhibits a Lorentzian shape with a characteristic frequency of several kilohertz. Frequency and conventional time domain measurements carried out with the same device as a function of antigen concentration show more than 10-fold increase in detection sensitivity in the frequency domain data. These concentration-dependent results together with studies of antibody receptor density effect further address possible origins of the Lorentzian frequency spectrum. Our results show that frequency domain measurements can be used as a complementary approach to conventional time domain measurements for ultrasensitive electrical detection of proteins and other biomolecules using nanoscale FETs.

Download full-text


Available from: Charles M Lieber
  • Source
    • "Potentiometry is one of the most simple electrochemical detection methods. Nanostructured biosensors based on field effect transistors (FETs) are considered members of this type [4] [5]. The miniaturized bio-FETs are able to detect nowadays large molecules such as plasma proteins or even bacteria [6] [7]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A comparison study on the performance characteristics and surface characterization of two different solid-contact selective potentiometric thrombin aptasensors, one exploiting a network of single-walled carbon nanotubes (SWCNTs) and the other the polyaniline (PANI), both acting as a transducing element, is described in this work. The molecular properties of both SWCNT and PANI surfaces have been modified by covalently linking thrombin binding aptamers as biorecognition elements. The two aptasensors are compared and characterized through potentiometry and electrochemical impedance spectroscopy (EIS) based on the voltammetric response of multiply charged transition metal cations (such as hexaammineruthenium, [Ru(NH3)6](3+)) bound electrostatically to the DNA probes. The surface densities of aptamers were accurately determined by the integration of the peak for the reduction of [Ru(NH3)6](3+) to [Ru(NH3)6](2+). The differences and the similarities, as well as the transduction mechanism, are also discussed. The sensitivity is calculated as 2.97 mV/decade and 8.03 mV/decade for the PANI and SWCNTs aptasensors, respectively. These results are in accordance with the higher surface density of the aptamers in the SWCNT potentiometric sensor.
    Full-text · Article · Feb 2013 · The Scientific World Journal
  • Source
    • "The state of the living system can be monitored by sensing different physical parameters, e.g., chemical, electrical, optical, thermal, magnetic, etc. There are indications that 1-D structures, such as semiconductor nanowires and CNTs, may offer superior sensitivity to planar devices and allow for picomolar detection of biomolecules [73]. An additional attractive feature of 1-D structures is that they might lend themselves to minimally invasive probes to contact or even puncture the cellular membrane, or even to be ingested into the cell itself. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, the historical effects and benefits of Moore's law for semiconductor technologies are reviewed, and it is offered that the rapid learning curve obtained to the benefit of society by feature size scaling might be continued in several different ways. The problem is that as features approach the range of a few nanometers, electron-based devices depart radically from the ideal switch and, in fact, become very leaky in the off state. It is argued that there are some short-term solutions involving more highly parallel manufacturing, increased design efficiency, and lower cost packaging technologies that could continue the steep learning curve for cost reductions that have historically been achieved via Moore's Law scaling. Another alternative might be to increase chip functionality by integrating devices that offer broadened chip functionality including, e.g., sensors, energy sources, oscillators, etc. A third alternative would be to invent an entirely new information processing state variable based on different physics, using electron spin, magnetic dipoles, photons, etc., to improve the performance and reduce switching energy for devices whose smallest features are on the order of a few nanometers. Each of these alternatives is being actively explored and an overview of each strategy and progress to date is given in the paper. A final alternative offered in the paper is to learn from information processing examples in nature, specifically in living systems. An E.coli cell of about one cubic micrometer volume is shown to be an incredibly powerful and energy-efficient information processor relative to the performance of an end-of-scaling silicon processor of the same volume. The paper concludes by pointing out some of the crucial differences between E.coli information processing and conventional approaches with the hope technologies can be invented using the hints offered by biosystems.
    Preview · Article · May 2012 · Proceedings of the IEEE
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present a simple mathematical model of adsorbed mass fluctuations in microcantilever sensors operating in liquids, taking into account the effects of the transfer process of analyte molecules from a solution to the sensor surface. Using the derived expressions the analysis is performed in order to estimate the influence of mass transfer on the equilibrium fluctuations of the measured signal. The results show that mass transfer significantly influences the spectrum of fluctuations. The theory is useful for determination of limiting performances of cantilever sensors and for characterization of molecular binding-unbinding interactions using measured fluctuations in the sensor’s signal.
    No preview · Article · Sep 2012 · Microelectronic Engineering
Show more