ZnO nanostructures with different morphologies (nanowires, nanodisks, and nanostars) were synthesized hydrothermally. Gas sensing properties of the as-grown nanostructures were investigated under thermal and UV activation. The performance of the ZnO nanodisk gas sensor was found to be superior to that of other nanostructures (Sg ∼ 3700% to 300 ppm ethanol and response time and recovery time of ...

We propose and theoretically demonstrate a bottle resonator sensor with a nanoscale altitude and with alength several of hundreds of microns made on the top of the fiber with a radius of tens microns for refractive index and temperature sensor applications. The whispering gallery modes (WGMs) in the resonators can be excited with a taper fiber placed on the top of the resonator. These sensors c...

Nanoscale Field Effect Transistors have emerged as a promising technology for ultrasensitive, unlabeled diagnostic applications. However, their use as quantitative sensors has been problematic because of the need for individual sensor calibration. In this work we demonstrate an internal calibration scheme for multiplexed nanoribbon field effect sensors by utilizing the initial current rates rat...

There is a strong demand for portable systems that can detect and characterize individual pathogens and other nanoscale objects without the use of labels, for applications in human health, homeland security, environmental monitoring and diagnostics. However, most nanoscale objects of interest have low polarizabilities due to their small size and low refractive index contrast with the surroundin...

We demonstrate a versatile class of nanoscale chemical sensors based on single stranded RNAs (ssRNAs) as the chemical recognition sites and single-walled carbon nanotube field effect transistors (SWNT-FETs) as the electronic readout components. The sensor responses differ in sign and magnitude depending on both the type of gaseous analyte and the sequence of ssRNA being used. Such rapid respons...

We have fabricated submicron giant magnetoresistive (GMR) structures and evaluated their sensitivity for biomagnetic applications. GMR devices were fabricated using electron beam lithography, with minimum dimensions below 100 nm. We developed a new characterization technique for these sensors, using a scanned nanoscale magnetic probe and monitoring the resulting response of the sensors. The mag...

The development of sensors for detecting foodborne pathogens has been motivated by the need to produce safe foods and to provide better healthcare. However, in the more recent times, these needs have been expanded to encompass issues relating to biosecurity, detection of plant and soil pathogens, microbial communities, and the environment. The range of technologies that currently flood the sens...

This article presents a low-noise high-bandwidth giant magnetoresistance (GMR) sensor-readout circuit for nanometer resolution position sensing, critical requirement in several precision applications such as Atomic Force Microscopy (AFM). The main impediment to performance is the GMR sensor’s significantly higher 1/f noise extending over large bandwidths, thereby limiting achievable SNR. Theref...