Biosensing platforms based on extracellular vesicles are currently receiving a lot of attention. The reason is that extracellular vesicles, which are endocytic lipid-membrane bound bodies, have the potential to be used as biomarkers in cancer and neurodegenerative disease and can be easily accessed via non-invasive liquid biopsies.
Biosensing to diagnose disease
In my research group we focus on fundamental questions related to how materials form and interact on the nanoscale with the overall ambition to develop novel methodologies supporting healthcare and the environment. Typically, we explore design strategies based on molecular self-assembly of polymers, nanoparticles, and biomolecules. Biosensing platforms, which could be used for sensitive detection of analytes enabling disease diagnosis, are an important area for us. In this context we explore novel biosensor architectures as well as different strategies to increase biosensor sensitivity and specificity.
Using QCM-D and EQCM-D analysis to monitor biosensor build-up and performance
The QCM-D analysis enabled us to monitor the surface immobilization of the nanoparticles, as well as the subsequent uptake and release of binding partners.Using the QCM-D data, we could also model the binding kinetics of the respective nanoparticle - analyte couples, and determine important binding parameters, such as the association and dissociation rate constants (kon and koff) and apparent binding constant Ka.
Developing new biosensor assays
Recently, we developed an approach for stepwise surface functionalization of biosensing surfaces with a particular focus on extracellular vesicles. The build-up of the surface architecture and performance was characterized by QCM-D and EQCM-D analysis.[2,3] As an example, with the ambition to enhance the sensitivity of the platform, we investigated a 2D and 3D nanostructuring of the QCM-D electrode.[4,5]
Listen to the webinar to learn more about biosensor development
Sign up for the webinar to learn more about our recent efforts on implementing QCM-D for reliable biosensing.
Probing nanoparticle-analyte interaction in real time via quartz crystal microbalance with dissipation monitoring - Y. Yang, G. Poss, N. Nianias, Y. Weng, R. Qi, H. Zheng, E. Kay, S. Guldin, Nanoscale, vol. 11, pp. 11107 – 11113, 2019.
Acoustic immunosensing of exosomes using a quartz crystal microbalance with dissipation monitoring - J. Suthar, E. Parsons, B. Hoogenboom, G. Williams, S. Guldin, Analytical Chemistry, vol. 92, pp. 4082 – 4093, 2020.
Dual-mode and label-free detection of exosomes from plasma using an electrochemical quartz crystal microbalance with dissipation monitoring - J. Suthar, B. Prieto-Simon, G.R. Williams, S. Guldin, Analytical Chemistry, vol. 94, pp. 2465 – 2475, 2022.
Silica inverse opal nanostructured sensors for enhanced immunodetection of extracellular vesicles by quartz crystal microbalance with dissipation monitoring - J. Suthar, A. Alvarez- Fernandez, G.R. Williams, S. Guldin, ACS Applied Nano Materials, DOI: 10.1021/acsanm. 2c02775, 2022.
Amplified EQCM-D detection of exosomes using 2D gold nanostructure arrays fabricated by block copolymer self-assembly – J.Suthar, A. Alvarez-Fernandez, G.R. Williams, S. Guldin, in preparation for submission.
Dr. Stefan Guldin is a full professor in Chemical Engineering, head of the Adaptive and Responsive Nanomaterials group, and deputy head of department (Enterprise) at University College London. His research interests include the study of material formation on the nanoscale by molecular self-assembly, creation of adaptive and responsive materials architectures, and translation into chemo- & biosensing applications.