FAQ

Principle: WWHS uses fluorescent nanospheres emitting in the second near-infrared window (NIR-II, >1,000 nm) as the signal label. Conjugated to specific antibodies, they form the core of the immunoassay system. In the test, the target analyte in the sample binds the labeled antibodies, producing a fluorescent signal on the test cartridge. The NIR-1000 analyzer reads the signal intensity in the NIR-II window and converts it — via a pre-established calibration curve — into a quantitative result. In essence, the technology combines immunochromatography with NIR-II optical detection: choosing a better optical window to raise the signal-to-noise ratio and quantitative stability.

Advantages:

• A. Lower background, higher signal-to-noise ratio. In the NIR-II window, absorption, scattering, and autofluorescence of common biological matrices (hemoglobin, lipids, bilirubin, etc.) drop sharply. Background noise is therefore far lower than with visible-light or NIR-I labels, yielding a higher SNR.
• B. Higher sensitivity for low-concentration quantification. With such low background, the effective signal is easier to isolate and amplify — delivering sensitivity approaching chemiluminescence, without magnetic-bead separation or complex washing steps.
• C. Better quantitative stability and reproducibility. NIR-II is less affected by ambient light, and the signal is less sensitive to sample color or mild hemolysis and lipemia, improving within-run and between-run repeatability.
• D. High performance with a simple workflow. The technology keeps the simplicity and speed of immunochromatography.
• E. A foundation for multi-analyte, platform-based testing. The nanospheres' optical tunability and batch-to-batch consistency allow different assays to be standardized and scaled on a single platform.

Mostly in-vivo imaging. Vascular angiography, cerebral and cerebrovascular imaging, tumor margin definition and surgical navigation, sentinel lymph node mapping, tracking stem cells and immune cells in vivo, and drug biodistribution — these have been the most active NIR-II fields over the past decade. In small-animal work, tissue transmission across 850–1,650 nm exceeds 92%, resolution reaches the 10-micron range, and acquisition can run at up to 2,000 frames per second. Longer-wavelength sub-windows such as NIR-IIb (1,500–1,700 nm) scatter less and deliver higher signal-to-noise.

In 2009, Professor Hongjie Dai's group reported the first in-vivo fluorescence imaging beyond 1 μm in Nature Nanotechnology, laying the groundwork for what later became the NIR-II window (1,000–1,700 nm). For more than a decade afterwards, the work stayed mostly in in-vivo imaging and materials science. Co-engineering the light source, the nanospheres, and the detector, then clearing stability validation and registration, takes a long cycle — which is one reason NIR-II remained largely a laboratory technique with few finished products.

The NIR-1000 is a dry fluorescence immunoanalyzer built on NIR-II fluorescence. It is positioned for primary-care POCT across three settings: chest pain centers and emergency departments in tertiary hospitals, county medical communities, and private clinics. The design trade-off is deliberate — as straightforward to operate as a colloidal gold strip, while returning a reliable quantitative result, at a cost primary care can carry.