Photonic Crystal Fiber Nanosensors

Stevens Institute of Technology’s Dr. Henry Du and his research team have pioneered work on the integration of photonic crystal fibers (PCFs) with nanoscale technologies that will potentially lead to robust chemical and biological sensing devices. The National Science Foundation recently granted Du’s team $1.3 million to pursue a multidisciplinary project in the area.

Using molecular and nanoscale surface modification, state-of-the-art laser techniques, and computer simulation, their research seeks to enhance the prospects of PCF sensors, sensor arrays, and sensor networks for diverse applications such as remote and dynamic environmental monitoring, manufacturing process safety, medical diagnosis, early warning of biological and chemical warfare, and homeland defense.

“Through basic and applied research,” said Du, “the optically robust PCFs with surface-functionalized, axially-aligned air holes are expected to achieve a quantum leap in chemical and biological detection capability over conventional fiber-optic sensor technology.”

PCF sensors enabled by nanotechnology also have the potential to be a powerful research platform for in-situ fundamental studies of surface chemistry and chemical/biological interactions in microchemical and microbiological systems.

Specifically, PCFs will be fabricated via a modified sol-gel method for optical fibers with the aid of simulation-based design for optimum light-analyte interactions. Nanoscale surface functionalization will be conducted following two strategies:

1. Surface attachment of Ag nanoparticles mediated by 3-mercaptopropyltrimethoxysilane self-assembled monolayer (SAM) for chemical sensing of NOx, CO, and SO2, where surface-enhanced Raman scattering (SERS) can be exploited for high sensitivity and molecular specificity; and
2. Surface binding of biospecific recognition entities for biological sensing using the following recognition pairs: biotin/avidin, cholera toxin/anticholera toxin and organophosphorous hydrolase (OPH)/paraoxon, where SERS may also be exploited.

The functionalized hollow core or cladding air holes will be filled with analytes for evaluation of sensing capabilities of PCFs. Surface functionalization studies will employ various surface-sensitive analytical techniques. Sensing measurements will make use of a range of state-of-the-art laser techniques. Experimental studies will be augmented by computer simulation, taking into account of the effects of surface functionalization, analyte medium, and biospecific interactions on the optical characteristics of PCFs.

An interdisciplinary team of academic and industrial researchers cutting across a broad spectrum of disciplines has been assembled to carry out this project. The project also involves postdoctoral fellows, graduate students, and several undergraduate/high-school summer research scholars, thus affording them the training and exposure in chemical and biological sensing and monitoring, a priority area of federal R&D, in view of the challenges faced by the nation.

Broad dissemination of research findings will be achieved via conference presentations, publications, and yearly on-site workshops.

A program-specific website will also be developed for timely release of significant research outcomes. The project is being conducted in collaboration with OFS Laboratories (formerly the Optical Fiber Division, Bell Laboratories), a world leader in fiber optic research, via NSF’s GOALI mechanism.

The research team consists of Professor Du (PI), Stevens’ Department of Chemical, Biomedical, and Materials Engineering; Professor Svetlana Sukhishvili (Co-PI); Stevens’ Department of Chemistry and Chemical Biology; Professors Hong-Liang Cui (Co-PI), Rainer Martini (Faculty Fellow), and Kurt Becker (Faculty Fellow), Stevens’ Department of Physics and Engineering Physics; Professor Christos Christodoulatos (Co-PI), Stevens’ Center for Environmental Systems; and Dr. Ryan Bise (Co-PI), OFS Laboratories (formerly Fiber Optic Research Department of Bell Laboratories).

Source: Stevens Institute of Technology

Related stories:

Chemical 'orienteering': how accurately can cells follow a chemical trail to find their way around?
(PhysOrg.com) -- Scientists have long known that single-cell organisms find their way around by detecting chemicals in their surroundings. Now new research out this week in the Proceedings of the National Academy of Sciences (PNAS) journal has shown how accurately cells are able to do this.
That tastes -- sweet? Sour? No, it's definitely calcium!
Chemists in Philadelphia are reporting a discovery that could expand the palate of human tastes — sweet, sour, salty, bitter, and savory — to include a new taste sensation that they term "calcium."
'Edible optics' could make food safer
Imagine an edible optical sensor that could be placed in produce bags to detect harmful levels of bacteria and consumed right along with the veggies. Or an implantable device that would monitor glucose in your blood for a year, then dissolve.
Scientists demonstrate highly directional semiconductor lasers
Applied scientists at Harvard collaborating with researchers at Hamamatsu Photonics in Hamamatsu City, Japan, have demonstrated, for the first time, highly directional semiconductor lasers with a much smaller beam divergence than conventional ones.
Study reveals principles behind stability and electronic properties of gold nanoclusters
A report published in the July 8 issue of the journal Proceedings of the National Academy of Sciences (PNAS) is the first to describe the principles behind the stability and electronic properties of tiny nanoclusters of metallic gold. The study, which confirms the "divide and protect" bonding structure, resulted from the work of researchers at four universities on two continents.
Northwestern chemist investigates lost reds in Homer painting
More than 30 years ago, when Northwestern University chemist Richard Van Duyne developed a powerful new sensing technique, he never thought he would be using it to learn more about treasures in the Art Institute of Chicago's collection -- including a watercolor recently featured in the museum's exhibition "Watercolors by Winslow Homer: The Color of Light."
New detector uses nanotubes to sense deadly gases
Using carbon nanotubes, MIT chemical engineers have built the most sensitive electronic detector yet for sensing deadly gases such as the nerve agent sarin.
Toy-Like Microboat Could Carry Tiny Cargoes
As a child, Cheng Luo, an engineer from the University of Texas at Arlington, recalls playing with wooden toy boats that were propelled forward when a drop of oil was placed on the back of the boats. When the oil slid off into the water, it created lower surface tension behind the boat than in front, which pushed the boat forward. This surface-tension-based propulsion is called the Marangoni effect.

News discussion:

Nanotechnology news