Quantum dot conjugation
Evaluate QD coating, coupling conditions, antibody loading and colloidal behaviour while preserving recognition activity.
Fluorescent lateral flow / Melbourne, Australia
Quantum dot lateral flow assay development
Develop a fluorescent rapid test around your target, sample and readout. Radetec combines quantum dot (QD) surface chemistry, bioconjugation, lateral flow assay (LFA) optimisation and reader-based measurement in one development workflow.
When fluorescence fits the question
Build the label and the strip together.
Quantum dots can provide a fluorescent signal that is measured with a suitable reader. They are worth evaluating when the project calls for instrument-assisted detection or a calibrated response. The label alone does not determine sensitivity: antibody affinity, conjugation, background, sample matrix, membrane flow and reader settings all matter.
We first establish whether the assay chemistry can meet the intended detection range. Then we compare practical label and strip configurations against agreed criteria. A gold nanoparticle format can be a useful comparator when visual readout is important.
See our quantum dot materials and conjugation page for CdSe/ZnS, InP/ZnS and CuInS₂/ZnS options.
QD LFA development scope
From nanoparticle to readable signal.
Strip and sample workflow
Select capture chemistry, membranes, buffers and sample handling to balance flow, specific signal and background.
Reader-based evaluation
Measure test and control line signals, assess detection range and repeatability, and explore semi-quantitative or quantitative readouts where feasible.
Technical considerations
What makes a QDs LFA work?
Target and assay format
Protein biomarkers and other analytes call for different capture strategies. We review whether available reagents support a sandwich assay or whether a competitive approach deserves investigation.
QD surface and conjugation
Particle coating, hydrodynamic size and conjugation orientation affect movement through the strip and binding at the test line. Surface chemistry is evaluated with the whole assay in mind.
Signal and background
Bright particles do not help if non-specific binding or sample fluorescence obscures the target signal. We assess blocking, buffer formulation, membrane choice and controls together.
Reader and calibration
Excitation, optical filters, exposure and analysis settings influence measured intensity. A semi-quantitative or quantitative claim needs a defined calibration and performance study for the intended matrix.
Frequently asked questions
Are quantum dots always more sensitive than gold nanoparticles?
No. Fluorescence can improve signal measurement with the right reader, but detection limits depend on the recognition chemistry, strip design, matrix and background. We compare approaches against your target requirements.
Can you work with our existing antibodies?
Yes. We can evaluate existing antibodies for QD conjugation and capture. If pairing or affinity is uncertain, reagent screening can be part of feasibility.
Can a QD LFA give a number rather than a positive or negative result?
Reader-assisted assays can be developed toward semi-quantitative or quantitative analysis when the response is suitable. The usable range, calibration and precision must be established experimentally.
Can you improve an existing fluorescent LFA?
Yes. We can focus on weak test lines, high background, poor conjugate release, matrix interference or inconsistent reader results. See our assay optimisation service.
Our QD lateral flow development can begin with a feasibility study or a specific technical bottleneck. Project outputs may include a conjugate preparation protocol, prototype strips, readout workflow and analytical evaluation against agreed criteria.
Explore nanoparticle bioconjugationStart with your target
Planning a fluorescent LFA?
Tell us the analyte, sample matrix, required detection range, available antibodies and development stage. We can define a practical first experiment.
Discuss your project