PARC Optical Characterization Systems

Optical Characterization Systems
Example Application: Low-cost and compact class identification of biomolecules moving in fluids

The Problem


PARC's prototype compact chip-size spectrometer, mounted to a fluidic chamber.

The U.S. Office of Naval Research needed fast, sensitive, and easily deployable methods to identify and handle bio-molecules for portable flow-through water purification systems.

However, conventional laboratory approaches are expensive, time-consuming, and impractical for the field (especially for large expeditions on ships). Meanwhile, other portable technologies such as MEMS-based spectometers are too expensive or not compact enough for field use.

The Solution

PARC scientists developed fast, sensitive, and specific methods to detect and characterize analytes of interest. These analytes can include bio-agents, toxins, nanoparticles, micro-organisms, fungi, and viruses moving in water, food, blood, air, and other samples.


PARC's platform uses novel optical detector technologies, readily available system components, and cost-effective processing techniques to enable compact yet fully integrated systems. These systems:
-	provide warnings about suspicious particles and simultaneously classify them as well;
-	enable "on-the-fly" detection of moving particles without requiring concentration and without losing throughput capacity;
-	enable point-of-care detection and portability between systems;
-	allow secondary processing of bio-molecules such as identification, removal, disinfection, capture, or sorting;
-	are sensitive without using reagents (primers, binders, tagging chemicals, stains);
-	are automated and do not require expert operators; and
-	yield detailed spectral data, which is necessary to differentiate agents in complex mixtures.

How It Works

(a) Schematic cross-section of characterization platform with chip-size wavelength detector and a fluidic channel that incorporates an anti-resonant waveguide.

(b) Photograph of fluidic chamber where fluorescence light is anti-resonantly excited along the channel.

Class identification of selected stimulants via multi-color native fluorescence: 1) various analytes were excited with UV lasers; 2) their emission spectra were recorded; and 3) a systematic computational method was used to identify classification rules for them.

Building on PARC's chip-size spectrometers and anti-resonant waveguides, the system takes advantage of optical source motion and enhanced light-analyte interaction.

It uses native fluorescence of the biomolecules to eliminate the need for reagents; is well-suited for multi-signal analyses since it is unaffected by wavelength changes and film thickness; and enables various optical characterization techniques (e.g., multi-color auto-fluorescence, Raman spectroscopy, IR absorption) along the length of the fluidic channel by using different, sequentially addressed intensity/ wavelength selective detectors.

Applications

PARC's optical detector system is extensible and can be configured for various applications including: