Research applications​

Affinité's innovations generated 20+ scientific papers in bioanalytical and other areas

Quantitative measurement of a drug or biomarker in biological fluids, primarily blood, plasma, serum, urine or tissue.

Assessment of the quality of the environment in order to control the risk of pollution and potential harm to humans.

Discovering new plasmonic and chemical materials. Exploiting their optical properties for biosensing applications.

Breast Cancer Biomarker 

Approximately one in five women diagnosed with breast cancer worldwide will have HER2-positive breast cancer, a particularly aggressive form of the disease. Although four diagnostic tests exist, research has shown that some HER2 status test results may still be wrong. 

A diagnostic test using SPR may help address some of the current issues. The potential biosensing application of a new ultra-low fouling ionic liquid is demonstrated using the P4SPR for the analysis of HER2 in breast cancer cell lysates. 

Small Peptide Detection

Elucidating  a mechanism of CD36

CD36 is a scavenger receptor important in age-related macular degeneration and other diseases. CD36 transmembrane proteins have diverse roles in lipid uptake, cell adhesion and pathogen sensing. Despite numerous in vitro studies, how they act in native cellular contexts is poorly understood. In an investigation with a Drosophila CD36 homologue, SNMP1, the P4SPR was employed to assess small-molecule interactions with a CD36 sensor chip.


DNA Detection

Potential new therapeutic pathway for infectious and autoimmune diseases 

Cytokine release syndrome is a form of systemic inflammatory response syndrome that arises as a complication of some diseases or infections, and is also an adverse effect of some monoclonal antibody drugs and other treatments. Severe cases have been called “cytokine storms” and can be fatal. 

Understanding the mechanism of inflammation is important. Here, the P4SPR was deployed to investigate the binding of a gene (EBI3) to IL-6, a pro-inflammatory cytokine. This unexpected observation could lead to a new therapeutic biologic for autoimmune diseases. 

Protein-Protein Detection

Development of an allergy testing immunosensor for a leukemia treatment

E. Coli L-asparaginase II (EcAII) is a critical component of chemotherapy for childhood acute lymphoblastic leukemia (ALL). This therapeutic, listed as essential medicine by the WHO since 1995, may be compromised by allergic reactions, overt or silent. The main concern relative to the silent hypersensitivity that occurs in 5-46% of patients is the development of neutralizing antibodies that result in silent inactivation of the treatment.

In order to monitor the efficacy of the treatment with EcAII, a test to detect the anti-EcAII antibodies (neutralizing antibodies) using the P4SPR. SPR bioassays were performed in undiluted serum from children undergoing therapy for ALL.

Cancer Therapeutic

Monitoring therapeutic drugs for dosage optimization

Methotrexate (MTX) is one of the most widely studied and effective therapeutics agents available to treat many solid tumors, hematologic malignancies, and autoimmune diseases such as rheumatoid arthritis; however, the poor pharmacokinetic and narrow safety margin of the drug limits the therapeutic outcomes of conventional drug delivery systems.

MTX concentrations in a patient’s serum undergoing chemotherapy treatments can be determined by surface plasmon resonance (SPR) sensing using folic acid-functionalized gold nanoparticles (FA-AuNP) in competition with MTX for the bioreceptor, human dihydrofolate reductase (hDHFR) immobilized on the SPR sensor chip.

Explosive Residue Detection

In the field environmental monitoring of explosive residues in ground water

Rapid detention explosives (RDX) have been used extensively in the manufacture of munitions and accounts for a large part of the explosives contamination at active and former military installations in various parts of the world. Most RDX are not significantly retained by most soil and biodegrade very slowly. As a result, it can easily migrate to groundwater. They are classified as possibly carcinogen and can damage the nervous system if inhaled or ingested.

See how the P4SPR was deployed on the field to test RDX in water at levels near the EPA limit of 2 ppb.

Plasmonic films

A new class of plasmonic material for biosensing

Surface plasmon resonance as an analytical technique has been used in industry for more than 30 years. While instrumentation and assays have significantly evolved, the core material of SPR, thin Au films, have remained constant. It is proven that using 2D and 3D shaped sensors can significantly improve sensitivity but often at the cost of reproducibility which is problematic for industrial applications. 

Here the P4SPR was use to characterize the plasmonic response and analytical parameters of a new class of thin films: microhole arrays. This new class of material can improve sensitivity up to 45% and is compatible with the majority of SPR systems currently on the market. 


Biofiltration System

Towards point-of-care SPR testing

Chemical measurements are rarely performed in crude blood due to the poor performance of sensors and devices exposed to biofluids. In particular, biosensors have been severely limited for detection in whole blood due to surface fouling from proteins, the interaction of cells with the sensor surface and potential optical interference when considering optical methods of analysis. 

To solve this problem, a dialysis chamber was introduced to a surface plasmon resonance (SPR) biosensor to create a diffusion gate for large molecules. This dialysis chamber relies on the faster migration of small molecules through a microporous membrane towards a sensor, located at a specified distance from the membrane. 

Analytical Integration

Dual analytical methods for enhanced performances

ELISA and SPR are complementary. ELISA has high sensitivity but does not inform about kinetics or affinity of a specific biomolecular interaction. Consequently, researchers must perform two separate experiment to gather ELISA and SPR information which cost precious money and time. Therefore, a combined ELISA and SPR device could shorten the process and potentially accelerate key discoveries.

A multi-channel system combining fluidics and micropatterned plasmonic materials with wavelength interrogation SPR and fluorescence detection was integrated from the combination of a small and motorized fluorescence microscope mounted on the P4SPR.

Surface Chemistry
Antifouling Property Characterization

Development of a low biofouling surface chemistry for biosensing

Biomaterials such as protein, DNA and cells have a tendency to stick to metallic and polymer surface which is problematic for assays and diagnostic tests. Surface chemistry coatings are employed to reduce this undesired effect.

Here, it was found that short peptides significantly reduce nonspecific binding adsorption of proteins in complex biological matrices such as serum and crude lysate. The effect of the short peptide on reducing nonspecific adsorption was demonstrated by quantifying beta-lactamase in crude lysate using SPR. A library of short peptide was studied and compared to standard surface chemistry such as dextran and PEG.

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