Sensitivity
Even subtle binding is visible
Fragments, low affinity hits and low abundance targets produce signal instead of noise. Baseline noise sits typically below 0.1 RU RMS.
How label-free biosensing works with a photonic biosensor
The inQuiQ is a photonic ring-resonator biosensor that uses nanophotonic evanescent field sensing (NES) to detect binding through an evanescent field at the sensor surface, similar to surface plasmon resonance (SPR).
NES advances these principles using photonic integrated circuits on a silicon chip, so one multiplex optical biosensor reads many targets at a lower cost of ownership.
NES advances these principles using photonic integrated circuits on a silicon chip, so one multiplex optical biosensor reads many targets at a lower cost of ownership.
Label-free biosensing with ring resonators in five steps
Label-free biosensing means nothing is stained, tagged, or amplified. The molecule's own mass is the signal, and binding is recorded by the photonic ring resonators while it happens.
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At the right wavelength, the light resonates inside the ring, circulating many times and passing the same sensing area over and over.
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That tail defines the sensing area. Only molecules within the evanescent field influence the optical signal.
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Refractive index sensing describes how light interacts with a material. Even small changes affect the optical signal.
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Larger shifts indicate more bound material on the sensor surface.
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Fitting both phases returns ka, kd and KD from a single run.
n₁ > n₂ - light circulates in the ring
What NES brings to label-free biosensing
A photonic microring resonator guides light through a chip rather than reflecting it off a gold film like surface plasmon resonance, changing what label-free biosensing can do and cost.
Multiplexing
Many targets from one sample
Read many targets from one injection. The chip has 4 channels for in-flow immobilization, and 16 sensors that can be immobilized with a spotter.
compact system
A benchtop instrument
The instrument's footprint is only 30 by 40 cm, so you don't need a core facility to fit the inQuiQ label-free biosensor in your lab.
low cost
Lower cost through photonic architecture
The inQuiQ places complex optics in the photonic ring-resonator chip, enabling sensitive detection below 0.1 RU RMS at lower cost.
NES compared to SPR, BLI and ITC
Four label-free methods answer binding questions in different ways. How each one generates its signal shows up directly in sensitivity, throughput and cost.
The bands are qualitative and describe typical instruments in each category, not one product. Platforms within a category vary.
NES offers the strongest multiplexing and affordability in this comparison, while providing strong sensitivity and compatibility with complex matrices.
No method leads everywhere. BLI runs more samples per shift and handles crude material without microfluidics. ITC measures binding heat directly in solution, which no surface method does.
One label-free analysis platform for all your binding questions
Engineered Antibodies
Affinity, kinetics, and epitope binning for clone ranking.
Engineered antibodies
Small molecules
& Peptides
Reliable fragment screening and small molecule binding affinity, label-free.
Small molecules and peptides
Molecular Glues
& PROTACs
Protein degraders ternary complex kinetics and molecular glue screening.
Molecular glues and PROTACs
Complex Biological Matrices
Binding analysis in serum, plasma, and crude samples.
Complex biological matrices
Membrane proteins
GPCR ligand binding, lipid bilayer sensors, and construct comparison.
Membrane proteins
Aggregated Proteins
Characterization of aggregated proteins and protein self-association.
Aggregated proteins
Nucleic acids
Aptamer binding affinity, hybridization kinetics, and sequence specificity.
Nucleic acids
Questions about your application?
Tell us what you're measuring and we'll tell you whether the inQuiQ fits.
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Still have questions about NES?
Send it to an application scientist. You get an answer about your assay, and if the inQuiQ fits your workflow.
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Ask for a demo instead
A demo tailored to your assay and your targets, so you will get a clear picture if the inQuiQ is the right instrument to fill the gaps in your workflow.
Download the inQuiQ brochure
Sensitivity, channel layout, footprint, and consumable formats in a couple pages.
Delta Life Science
request@deltalifescience.nl
Send us an email, and we will get back to you as soon as possible.
request@deltalifescience.nl
Send us an email, and we will get back to you as soon as possible.
Questions researchers ask
Yes, NES uses photonic ring-resonators. NES is a label-free biosensing technology that measures binding as a refractive index change at a sensor surface, a similar physical principle used by surface plasmon resonance (SPR) and grating-coupled interferometry (GCI). The sensing element is a photonic integrated circuit rather than a gold film. It returns affinity (KD) and kinetics (kon, koff) in real time, in a benchtop-sized instrument with a baseline noise typically below 0.1 RU RMS, or even below 0.01 RU RMS for high-sensitivity sensors.
A microring resonator is a ring-shaped waveguide on a chip. Light of certain wavelengths circulates in the ring. When molecules bind near the ring, the local refractive index changes and the resonance wavelength shifts. The instrument tracks that shift in real time, giving a sensorgram that is fitted for kon, koff and KD.
No. Label-free platforms fall into three groups. An SPR instrument (Cytiva Biacore, Bruker Sierra SPR, Carterra LSA) reads a gold film through a prism. BLI systems (Sartorius Octet, Gator Bio) read a dip sensor moved between wells. An optical biosensor built on a photonic chip reads light in a waveguide, which is how the inQuiQ from Delta Life Science fits 16 high sensitivity sensors on one chip in a benchtop instrument.
All three detect binding without labels. Surface plasmon resonance reads a gold film through a prism, with complex optical components contributing to the cost of the instrument. Bio-layer interferometry reads a dip sensor moved between wells, making it well suited to complex matrices, but generally less sensitive for fragments and small molecules. NES integrates highly sensitive waveguide sensors directly onto a silicon photonic chip, enabling the inQuiQ to combine high sensitivity with 16 sensors in a compact, more affordable benchtop system.
The inQuiQ covers the same core measurements: KD, kon, koff, specificity, epitope binning and active concentration, across affinities from 10 pM to 10 mM. What changes is access. NES enables an affordable instrument with a sensitivity of up to 0.01 RU RMS, running serum and lysate directly after a 0.22 µm filter, sensors regenerate for reuse, and the instrument sits on your own bench.
Label-free detection means no stain, tag or amplification sits on either binding partner. ELISA returns an endpoint, meaning how much analyte is present after washing and detection. Label-free methods like nanophotonic evanescent field sensing record binding as it happens, so one run gives association rate, dissociation rate and affinity, and the inQuiQ reads unpurified samples without a coating, blocking or detection step.
Every run with the inQuiQ returns a sensorgram: association while sample flows over the surface, dissociation while buffer flows. Fitting both phases gives kon, koff and KD. The inQuiQ covers 10 pM to 10 mM, association rates from 10¹ to 10⁷ M⁻¹s⁻¹, dissociation rates from 1 to 10⁻⁶ s⁻¹, with baseline noise below 0.1 RU RMS for sensitivity sensors, down to 0.01 RU RMS for high sensitivity sensors.
Binding affinity is measured as the dissociation constant KD, either from the rate constants or from equilibrium. A label-free instrument flows the analyte over an immobilised target, records association and dissociation as a sensorgram, and fits both phases to give kon, koff and KD. Steady-state fitting gives KD directly where the interaction reaches equilibrium. The inQuiQ covers 10 pM to 10 mM.
inQuiQ in scientific literature
The microring resonator approach behind NES technology and inQuiQ has also been covered in the physics literature. A 2025 paper from the AIT Austrian Institute of Technology describes this approach and contrasts it with a lifetime-based sensing method that the authors propose.
Morozov YM, Lapchuk AS. Quantum emitters in silicon: Purcell-enhanced lifetime modulation as a probe of local refractive index changes. Physical Review Applied, 2025. https://doi.org/10.1103/xj8f-nvt3
Morozov YM, Lapchuk AS. Quantum emitters in silicon: Purcell-enhanced lifetime modulation as a probe of local refractive index changes. Physical Review Applied, 2025. https://doi.org/10.1103/xj8f-nvt3