Nanoparticle Sensors and Nanoparticle-Based Detector Systems

Description:
These are sensor systems that both detect nanoparticles and rely on the formation of nanoparticles that have been developed as sensing species.

Broad Fields of Use:
Sensors can employ nanotechnology in two ways. First, sensors can be developed for the detection and study of nanoparticles in programs whose primary focus is the synthesis and production of nanoparticles. Second, however, one also can employ nanoparticles and the process of their formation as part of sensor systems that utilize the nanoparticles as a basis of detecting other chemicals and materials. The detection of gases, for example, can use the formation of nanoparticles as detectors for the gas of interest. Chemical species that are formed in this manner as the basis of the sensor system are nanosize in nature. The approach can be extended to liquids and solutions as well as gases. The mechanism on which the two sensor applications are based also can be used to synthesize new nanoparticle systems.

Comparison with Current Technologies:
There is no single commercially available sensor on the market that uses nanoparticle-based sensing technology as such. Sensors we have designed are capable of detecting a number of liquids and gases that are of industrial and commercial interest through the mechanism of forming nanoparticles and clusters that serve as the sensing platform.

Nanoparticles and related nanoclusters originating from synthetic schemes targeted at nanophase materials in the laboratory are detectable by a number of means we are currently using. By using the approach we have employed for the development of nanotechnology in sensors, one can gain much valuable information with respect to the mechanism by which they work.

Description of Current Application:
We have developed a technique for the use of nanoparticles to act as sensors for a variety of chemicals, with the sensors responding to the nanoparticles that are formed from the interaction between the sensor and the analyte of interest. Alternately, we have developed new techniques for the characterization of nanoparticles and their morphology and chemistries, particularly with respect to nanogram and sub-nanogram contaminants.

Figure 1. The structures of the α-PbO (litharge) (a) and β-PbO (massicot) (b) phases of lead(II) oxide. The solid lines represent the unit cell frameworks of the molecules.

Figure 2. X-ray diffractogram of freshly prepared α-PbO, litharge.

The techniques used to study nanoparticles and nanoclusters yield information concerning oxidation state, electronic state, and magnetic state data for the elements that comprise the chemical composition of the particles. They allow a researcher to follow very discrete changes in the chemistry of the particles as well as any structural changes.

Important advantages of the techniques are the ability to gather here-to-fore impossible to obtain detailed chemical information on nanoparticles. The increased sensitivity and detection limits of elemental species involved in nanoparticle rapid response allows for the measurement of particle changes as a function of particle synthesis and history. The techniques have applications in biomaterials, electronics, coatings, and other areas in which nanomaterials are of interest.

Contact and Brief Bio:

Dale L. Perry, Senior Scientist
Phone: (510) 486-4819
E-mail:

MS 70A1150
Sensors Group
Lawrence Berkeley National Laboratory
Berkeley, CA 94720