Search

Continued advances in label-free electrical biosensors pave the way to simple, rapid, cost-effective, high-sensitivity, and quantitative biomarker testing at the point-of-care setting that would profoundly transform healthcare. However, implementation in routine diagnostics is faced with significant challenges associated with the inherent requirement for biofluid sample processing before and during testing. We present here a simple yet robust autonomous finger-prick blood sample processing platform integrated with nanoscale field-effect transistor biosensors and demonstrate the feasibility of measuring the SARS-CoV-2 nucleocapsid protein. The 3D-printed platform incorporates a high-yield blood-to-plasma separation module and a delay valve designed to terminate the assay at a specific time. The platform is driven by hydrostatic pressure to efficiently and automatically dispense plasma and washing/measurement buffer to the nanosensors. Our model study demonstrates the feasibility of detecting down to 1.4 pg/mL of the SARS-CoV-2 nucleocapsid protein within 25 min and with only minimal operator intervention. Refereed/Peer-reviewed

Development of new detection methodologies and amplification schemes is indispensable for plasmonic biosensors to improve the sensitivity for the detection of trace amounts of analytes. Herein, an ultrasensitive scheme for signal enhancement based on the concept of surface-plasmon-resonance-enhanced light scattering (SP-LS) was validated experimentally and theoretically. The SP-LS of gold nanoparticles' (AuNPs) tags was employed in a sandwich assay for the detection of cardiac troponin I and provided up to 2 orders of magnitude improved sensitivity over conventional AuNPs-enhanced refractometric measurements and 3 orders of magnitude improvement over label-free SPR. Simulations were also performed to provide insights into the physical mechanisms. Refereed/Peer-reviewed

Internalized gold nanoparticles were quantified in large numbers of individual prostate cancer cells using large area synchrotron X-ray fluorescence microscopy. Cells were also irradiated with a 6 MV linear accelerator to assess the biological consequence of radiosensitization with gold nanoparticles. A large degree of heterogeneity in nanoparticle uptake between cells resulted in influenced biological effect. Refereed/Peer-reviewed