Label-free Biosensor
Label-free Biosensor - Related Videos
10:59
Use of Label-free Optical Biosensors to Detect Modulation of Potassium Channels by G-protein Coupled Receptors
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Cited by 5 •
2014
Optical biosensor techniques can detect changes in mass near the plasma membrane in living cells and allow one to follow cellular responses in both individual cells and populations of cells. This protocol will describe detection of the modulation of potassium channels by G-protein coupled receptors in intact cells using this approach.
13:21
In Vivo Biosensor Tracks Non-apoptotic Caspase Activity in Drosophila
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Cited by 5 •
2016
To detect healthy cells in whole animals that contain low levels of caspase activity, the highly sensitive biosensor designated CaspaseTracker was generated for Drosophila. Caspase-dependent biosensor activity is detected in long-lived healthy cells throughout the internal organs of adult animals reared under optimized conditions in the absence of death stimuli.
02:02
Detection of a Target Analyte Using a Bacterial Biosensor
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2025
Source: Barber, A. E., et al. Preparation and Application of a New Bacterial Biosensor for the Presumptive Detection of Gunshot Residue. J. Vis. Exp. (2019).This video demonstrates the detection of specific analytes using a bacterial biosensor. A bacterial culture carrying a plasmid with a red fluorescent protein (RFP) gene under an analyte-sensitive promoter is taken. After thoroughly wiping the test surface, a small section of the wipe is immersed in the culture and incubated. The analyte...
14:04
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
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Cited by 17 •
2013
Lytic phage biosensors and antibody beads are able to discriminate between methicillin resistant (MRSA) and sensitive staphylococcus bacteria. The phages were immobilized by a Langmuir-Blodgett method onto a surface of a quartz crystal microbalance sensor and worked as broad range staphylococcus probes. Antibody beads recognize MRSA.
09:19
Simultaneous Label-Free Autofluorescence Multi-Harmonic Microscopy
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Cited by 3 •
2025
This protocol presents a step-by-step guide for the Simultaneous Label-free Autofluorescence Multi-harmonic (SLAM) microscopic technique, including details on how to generate the laser light source, prepare a tissue sample, conduct imaging, and analyze the data. SLAM advances nonlinear microscopy by measuring four complementary label-free contrasts to investigate the tissue microenvironment.
FAQs
The transducer converts a biological interaction into a measurable physical or electrical response. Binding can alter surface mass, charge distribution, optical refractive index, electrical impedance, or mechanical behavior, depending on the platform design. Measuring that change allows the system to track recognition events directly, supporting rapid analysis and, in suitable configurations, real-time observation of biological processes.
These recognition elements provide the molecular selectivity needed to distinguish a target analyte from other sample components. An antibody, nucleic acid, or engineered receptor interacts with its corresponding molecule or biological target, and the resulting interaction changes a property measured by the transducer. Selecting the recognition element therefore strongly influences what the device can detect and how specifically it responds.
Because the target does not require a fluorescent, radioactive, or enzymatic tag, the workflow can avoid an additional labeling step and reduce sample preparation. Direct measurement may also support faster signal generation and real-time observation. These advantages are especially relevant when researchers need streamlined assays, although performance still depends on the recognition element, transducer, and biological sample.
Sensitivity and selectivity arise from the combined performance of the recognition element and transducer. Recognition chemistry determines which analyte produces a response, while the transducer determines how binding-related changes in mass, charge, refractive index, impedance, or mechanics are captured. Device miniaturization can support compact formats, but the overall analytical value depends on preserving reliable target discrimination and measurable signal changes.
A typical workflow begins by choosing a recognition element for the biological target and integrating it with a compatible transducer. The sample is then brought into contact with the sensing system, and binding or cellular activity is monitored through the selected physical signal. Researchers interpret that response to evaluate the target, biomarker, pathogen, drug effect, or cell behavior under investigation.
These platforms are useful when direct, rapid, or potentially continuous measurements are important. Bioengineers can apply them to biomarker detection, pathogen monitoring, drug screening, and analysis of cellular activity. Their simplified workflows and potential for miniaturization also support point-of-care diagnostics and continuous biological monitoring, where compact operation and reduced preparation can improve practical usability.